diff --git a/binding/bitmap-binding.cpp b/binding/bitmap-binding.cpp
index ee77646c..5af6deb4 100644
--- a/binding/bitmap-binding.cpp
+++ b/binding/bitmap-binding.cpp
@@ -49,6 +49,12 @@ void bitmapInitProps(Bitmap *b, VALUE self) {
     b->setInitFont(font);
     
     rb_iv_set(self, "font", fontObj);
+
+    // Leave property as default nil if hasHires() is false.
+    if (b->hasHires()) {
+        b->assumeRubyGC();
+        wrapProperty(self, b->getHires(), "hires", BitmapType);
+    }
 }
 
 RB_METHOD(bitmapInitialize) {
@@ -94,6 +100,8 @@ RB_METHOD(bitmapHeight) {
     return INT2FIX(value);
 }
 
+DEF_GFX_PROP_OBJ_REF(Bitmap, Bitmap, Hires, "hires")
+
 RB_METHOD(bitmapRect) {
     RB_UNUSED_PARAM;
     
@@ -741,6 +749,9 @@ void bitmapBindingInit() {
     
     _rb_define_method(klass, "width", bitmapWidth);
     _rb_define_method(klass, "height", bitmapHeight);
+
+    INIT_PROP_BIND(Bitmap, Hires, "hires");
+
     _rb_define_method(klass, "rect", bitmapRect);
     _rb_define_method(klass, "blt", bitmapBlt);
     _rb_define_method(klass, "stretch_blt", bitmapStretchBlt);
diff --git a/binding/graphics-binding.cpp b/binding/graphics-binding.cpp
index 75095c2c..6873f35e 100644
--- a/binding/graphics-binding.cpp
+++ b/binding/graphics-binding.cpp
@@ -19,6 +19,7 @@
  ** along with mkxp.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "config.h"
 #include "graphics.h"
 #include "sharedstate.h"
 #include "binding-util.h"
diff --git a/mkxp.json b/mkxp.json
index afa41c51..8a3649c7 100644
--- a/mkxp.json
+++ b/mkxp.json
@@ -91,6 +91,35 @@
     // "lanczos3Scaling": false,
 
 
+    // Replace the game's Bitmap files with external high-res files
+    // provided in the "Hires" directory.
+    // (You'll also need to set the below Scaling Factors.)
+    // (default: disabled)
+    //
+    // "enableHires": false,
+
+
+    // Scaling factor for textures (e.g. Bitmaps)
+    // (higher values will look better if you use high-res textures)
+    // (default: 1.0)
+    //
+    // "textureScalingFactor": 4.0,
+
+
+    // Scaling factor for screen framebuffer
+    // (higher values will look better if you use high-res textures)
+    // (default: 1.0)
+    //
+    // "framebufferScalingFactor": 4.0,
+
+
+    // Scaling factor for tileset atlas
+    // (higher values will look better if you use high-res textures)
+    // (default: 1.0)
+    //
+    // "atlasScalingFactor": 4.0,
+
+
     // Sync screen redraws to the monitor refresh rate
     // (default: disabled)
     //
diff --git a/src/config.cpp b/src/config.cpp
index 9048c6d7..58932abc 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -136,6 +136,10 @@ void Config::read(int argc, char *argv[]) {
         {"fixedAspectRatio", true},
         {"smoothScaling", false},
         {"lanczos3Scaling", false},
+        {"enableHires", false},
+        {"textureScalingFactor", 1.},
+        {"framebufferScalingFactor", 1.},
+        {"atlasScalingFactor", 1.},
         {"vsync", false},
         {"defScreenW", 0},
         {"defScreenH", 0},
@@ -261,6 +265,10 @@ try { exp } catch (...) {}
     SET_OPT(fixedAspectRatio, boolean);
     SET_OPT(smoothScaling, boolean);
     SET_OPT(lanczos3Scaling, boolean);
+    SET_OPT(enableHires, boolean);
+    SET_OPT(textureScalingFactor, number);
+    SET_OPT(framebufferScalingFactor, number);
+    SET_OPT(atlasScalingFactor, number);
     SET_OPT(winResizable, boolean);
     SET_OPT(vsync, boolean);
     SET_STRINGOPT(windowTitle, windowTitle);
diff --git a/src/config.h b/src/config.h
index ade1e64f..328df348 100644
--- a/src/config.h
+++ b/src/config.h
@@ -45,6 +45,10 @@ struct Config {
     bool fixedAspectRatio;
     bool smoothScaling;
     bool lanczos3Scaling;
+    bool enableHires;
+    double textureScalingFactor;
+    double framebufferScalingFactor;
+    double atlasScalingFactor;
     bool vsync;
     
     int defScreenW;
diff --git a/src/display/bitmap.cpp b/src/display/bitmap.cpp
index e97252b7..847539f1 100644
--- a/src/display/bitmap.cpp
+++ b/src/display/bitmap.cpp
@@ -237,11 +237,19 @@ struct BitmapPrivate
      * in the texture and blit to it directly, saving
      * ourselves the expensive blending calculation */
     pixman_region16_t tainted;
+
+    // For high-resolution texture replacement.
+    Bitmap *selfHires;
+    Bitmap *selfLores;
+    bool assumingRubyGC;
     
     BitmapPrivate(Bitmap *self)
     : self(self),
     megaSurface(0),
-    surface(0)
+    selfHires(0),
+    selfLores(0),
+    surface(0),
+    assumingRubyGC(false)
     {
         format = SDL_AllocFormat(SDL_PIXELFORMAT_ABGR8888);
         
@@ -326,16 +334,30 @@ struct BitmapPrivate
         return result != PIXMAN_REGION_OUT;
     }
     
-    void bindTexture(ShaderBase &shader)
+    void bindTexture(ShaderBase &shader, bool substituteLoresSize = true)
     {
+        if (selfHires) {
+            selfHires->bindTex(shader);
+            return;
+        }
+
         if (animation.enabled) {
+            if (selfLores) {
+                Debug() << "BUG: High-res BitmapPrivate bindTexture for animations not implemented";
+            }
+
             TEXFBO cframe = animation.currentFrame();
             TEX::bind(cframe.tex);
             shader.setTexSize(Vec2i(cframe.width, cframe.height));
             return;
         }
         TEX::bind(gl.tex);
-        shader.setTexSize(Vec2i(gl.width, gl.height));
+        if (selfLores && substituteLoresSize) {
+            shader.setTexSize(Vec2i(selfLores->width(), selfLores->height()));
+        }
+        else {
+            shader.setTexSize(Vec2i(gl.width, gl.height));
+        }
     }
     
     void bindFBO()
@@ -468,6 +490,24 @@ struct BitmapOpenHandler : FileSystem::OpenHandler
 
 Bitmap::Bitmap(const char *filename)
 {
+    std::string hiresPrefix = "Hires/";
+    std::string filenameStd = filename;
+    Bitmap *hiresBitmap = nullptr;
+    // TODO: once C++20 is required, switch to filenameStd.starts_with(hiresPrefix)
+    if (shState->config().enableHires && filenameStd.compare(0, hiresPrefix.size(), hiresPrefix) != 0) {
+        // Look for a high-res version of the file.
+        std::string hiresFilename = hiresPrefix + filenameStd;
+        try {
+            hiresBitmap = new Bitmap(hiresFilename.c_str());
+            hiresBitmap->setLores(this);
+        }
+        catch (const Exception &e)
+        {
+            Debug() << "No high-res Bitmap found at" << hiresFilename;
+            hiresBitmap = nullptr;
+        }
+    }
+
     BitmapOpenHandler handler;
     shState->fileSystem().openRead(handler, filename);
     
@@ -482,6 +522,8 @@ Bitmap::Bitmap(const char *filename)
     
     if (handler.gif) {
         p = new BitmapPrivate(this);
+
+        p->selfHires = hiresBitmap;
         
         if (handler.gif->width >= (uint32_t)glState.caps.maxTexSize || handler.gif->height > (uint32_t)glState.caps.maxTexSize)
         {
@@ -510,6 +552,9 @@ Bitmap::Bitmap(const char *filename)
             delete handler.gif_data;
             
             p->gl = texfbo;
+            if (p->selfHires != nullptr) {
+                p->gl.selfHires = &p->selfHires->getGLTypes();
+            }
             p->addTaintedArea(rect());
             return;
         }
@@ -583,6 +628,7 @@ Bitmap::Bitmap(const char *filename)
     {
         /* Mega surface */
         p = new BitmapPrivate(this);
+        p->selfHires = hiresBitmap;
         p->megaSurface = imgSurf;
         SDL_SetSurfaceBlendMode(p->megaSurface, SDL_BLENDMODE_NONE);
     }
@@ -602,7 +648,11 @@ Bitmap::Bitmap(const char *filename)
         }
         
         p = new BitmapPrivate(this);
+        p->selfHires = hiresBitmap;
         p->gl = tex;
+        if (p->selfHires != nullptr) {
+            p->gl.selfHires = &p->selfHires->getGLTypes();
+        }
         
         TEX::bind(p->gl.tex);
         TEX::uploadImage(p->gl.width, p->gl.height, imgSurf->pixels, GL_RGBA);
@@ -613,15 +663,30 @@ Bitmap::Bitmap(const char *filename)
     p->addTaintedArea(rect());
 }
 
-Bitmap::Bitmap(int width, int height)
+Bitmap::Bitmap(int width, int height, bool isHires)
 {
     if (width <= 0 || height <= 0)
         throw Exception(Exception::RGSSError, "failed to create bitmap");
     
+    Bitmap *hiresBitmap = nullptr;
+
+    if (shState->config().enableHires && !isHires) {
+        // Create a high-res version as well.
+        double scalingFactor = shState->config().textureScalingFactor;
+        int hiresWidth = (int)lround(scalingFactor * width);
+        int hiresHeight = (int)lround(scalingFactor * height);
+        hiresBitmap = new Bitmap(hiresWidth, hiresHeight, true);
+        hiresBitmap->setLores(this);
+    }
+
     TEXFBO tex = shState->texPool().request(width, height);
     
     p = new BitmapPrivate(this);
     p->gl = tex;
+    if (p->selfHires != nullptr) {
+        p->gl.selfHires = &p->selfHires->getGLTypes();
+    }
+    p->selfHires = hiresBitmap;
     
     clear();
 }
@@ -679,6 +744,10 @@ Bitmap::Bitmap(const Bitmap &other, int frame)
     other.ensureNonMega();
     if (frame > -2) other.ensureAnimated();
     
+    if (other.hasHires()) {
+        Debug() << "BUG: High-res Bitmap from animation not implemented";
+    }
+
     p = new BitmapPrivate(this);
     
     // TODO: Clean me up
@@ -762,6 +831,28 @@ int Bitmap::height() const
     return p->gl.height;
 }
 
+bool Bitmap::hasHires() const{
+    guardDisposed();
+
+    return p->selfHires;
+}
+
+DEF_ATTR_RD_SIMPLE(Bitmap, Hires, Bitmap*, p->selfHires)
+
+void Bitmap::setHires(Bitmap *hires) {
+    guardDisposed();
+
+    Debug() << "BUG: High-res Bitmap setHires not fully implemented, expect bugs";
+    hires->setLores(this);
+    p->selfHires = hires;
+}
+
+void Bitmap::setLores(Bitmap *lores) {
+    guardDisposed();
+
+    p->selfLores = lores;
+}
+
 bool Bitmap::isMega() const{
     guardDisposed();
     
@@ -809,13 +900,35 @@ void Bitmap::stretchBlt(const IntRect &destRect,
                         int opacity)
 {
     guardDisposed();
-    
+
     // Don't need this, right? This function is fine with megasurfaces it seems
     //GUARD_MEGA;
-    
+
     if (source.isDisposed())
         return;
-    
+
+    if (hasHires()) {
+        int destX, destY, destWidth, destHeight;
+        destX = destRect.x * p->selfHires->width() / width();
+        destY = destRect.y * p->selfHires->height() / height();
+        destWidth = destRect.w * p->selfHires->width() / width();
+        destHeight = destRect.h * p->selfHires->height() / height();
+
+        p->selfHires->stretchBlt(IntRect(destX, destY, destWidth, destHeight), source, sourceRect, opacity);
+        return;
+    }
+
+    if (source.hasHires()) {
+        int sourceX, sourceY, sourceWidth, sourceHeight;
+        sourceX = sourceRect.x * source.getHires()->width() / source.width();
+        sourceY = sourceRect.y * source.getHires()->height() / source.height();
+        sourceWidth = sourceRect.w * source.getHires()->width() / source.width();
+        sourceHeight = sourceRect.h * source.getHires()->height() / source.height();
+
+        stretchBlt(destRect, *source.getHires(), IntRect(sourceX, sourceY, sourceWidth, sourceHeight), opacity);
+        return;
+    }
+
     opacity = clamp(opacity, 0, 255);
     
     if (opacity == 0)
@@ -936,7 +1049,7 @@ void Bitmap::stretchBlt(const IntRect &destRect,
         quad.setTexPosRect(sourceRect, destRect);
         quad.setColor(Vec4(1, 1, 1, normOpacity));
         
-        source.p->bindTexture(shader);
+        source.p->bindTexture(shader, false);
         p->bindFBO();
         p->pushSetViewport(shader);
         
@@ -963,6 +1076,16 @@ void Bitmap::fillRect(const IntRect &rect, const Vec4 &color)
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        int destX, destY, destWidth, destHeight;
+        destX = rect.x * p->selfHires->width() / width();
+        destY = rect.y * p->selfHires->height() / height();
+        destWidth = rect.w * p->selfHires->width() / width();
+        destHeight = rect.h * p->selfHires->height() / height();
+
+        p->selfHires->fillRect(IntRect(destX, destY, destWidth, destHeight), color);
+    }
+
     p->fillRect(rect, color);
     
     if (color.w == 0)
@@ -992,6 +1115,16 @@ void Bitmap::gradientFillRect(const IntRect &rect,
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        int destX, destY, destWidth, destHeight;
+        destX = rect.x * p->selfHires->width() / width();
+        destY = rect.y * p->selfHires->height() / height();
+        destWidth = rect.w * p->selfHires->width() / width();
+        destHeight = rect.h * p->selfHires->height() / height();
+
+        p->selfHires->gradientFillRect(IntRect(destX, destY, destWidth, destHeight), color1, color2, vertical);
+    }
+
     SimpleColorShader &shader = shState->shaders().simpleColor;
     shader.bind();
     shader.setTranslation(Vec2i());
@@ -1039,6 +1172,16 @@ void Bitmap::clearRect(const IntRect &rect)
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        int destX, destY, destWidth, destHeight;
+        destX = rect.x * p->selfHires->width() / width();
+        destY = rect.y * p->selfHires->height() / height();
+        destWidth = rect.w * p->selfHires->width() / width();
+        destHeight = rect.h * p->selfHires->height() / height();
+
+        p->selfHires->clearRect(IntRect(destX, destY, destWidth, destHeight));
+    }
+
     p->fillRect(rect, Vec4());
     
     p->onModified();
@@ -1051,6 +1194,12 @@ void Bitmap::blur()
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        p->selfHires->blur();
+    }
+
+    // TODO: Is there some kind of blur radius that we need to handle for high-res mode?
+
     Quad &quad = shState->gpQuad();
     FloatRect rect(0, 0, width(), height());
     quad.setTexPosRect(rect, rect);
@@ -1097,6 +1246,11 @@ void Bitmap::radialBlur(int angle, int divisions)
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        p->selfHires->radialBlur(angle, divisions);
+        return;
+    }
+
     angle     = clamp<int>(angle, 0, 359);
     divisions = clamp<int>(divisions, 2, 100);
     
@@ -1161,7 +1315,7 @@ void Bitmap::radialBlur(int angle, int divisions)
     SimpleMatrixShader &shader = shState->shaders().simpleMatrix;
     shader.bind();
     
-    p->bindTexture(shader);
+    p->bindTexture(shader, false);
     TEX::setSmooth(true);
     
     p->pushSetViewport(shader);
@@ -1193,6 +1347,10 @@ void Bitmap::clear()
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        p->selfHires->clear();
+    }
+
     p->bindFBO();
     
     glState.clearColor.pushSet(Vec4());
@@ -1221,9 +1379,52 @@ Color Bitmap::getPixel(int x, int y) const
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        Debug() << "GAME BUG: Game is calling getPixel on low-res Bitmap; you may want to patch the game to improve graphics quality.";
+
+        int xHires = x * p->selfHires->width() / width();
+        int yHires = y * p->selfHires->height() / height();
+
+        // We take the average color from the high-res Bitmap.
+        // RGB channels skip fully transparent pixels when averaging.
+        int w = p->selfHires->width() / width();
+        int h = p->selfHires->height() / height();
+
+        if (w >= 1 && h >= 1) {
+            double rSum = 0.;
+            double gSum = 0.;
+            double bSum = 0.;
+            double aSum = 0.;
+
+            long long rgbCount = 0;
+            long long aCount = 0;
+
+            for (int thisX = xHires; thisX < xHires+w && thisX < p->selfHires->width(); thisX++) {
+                for (int thisY = yHires; thisY < yHires+h && thisY < p->selfHires->height(); thisY++) {
+                    Color thisColor = p->selfHires->getPixel(thisX, thisY);
+                    if (thisColor.getAlpha() >= 1.0) {
+                        rSum += thisColor.getRed();
+                        gSum += thisColor.getGreen();
+                        bSum += thisColor.getBlue();
+                        rgbCount++;
+                    }
+                    aSum += thisColor.getAlpha();
+                    aCount++;
+                }
+            }
+
+            double rAvg = rSum / (double)rgbCount;
+            double gAvg = gSum / (double)rgbCount;
+            double bAvg = bSum / (double)rgbCount;
+            double aAvg = aSum / (double)aCount;
+
+            return Color(rAvg, gAvg, bAvg, aAvg);
+        }
+    }
+
     if (x < 0 || y < 0 || x >= width() || y >= height())
         return Vec4();
-    
+
     if (!p->surface)
     {
         p->allocSurface();
@@ -1252,6 +1453,24 @@ void Bitmap::setPixel(int x, int y, const Color &color)
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        Debug() << "GAME BUG: Game is calling setPixel on low-res Bitmap; you may want to patch the game to improve graphics quality.";
+
+        int xHires = x * p->selfHires->width() / width();
+        int yHires = y * p->selfHires->height() / height();
+
+        int w = p->selfHires->width() / width();
+        int h = p->selfHires->height() / height();
+
+        if (w >= 1 && h >= 1) {
+            for (int thisX = xHires; thisX < xHires+w && thisX < p->selfHires->width(); thisX++) {
+                for (int thisY = yHires; thisY < yHires+h && thisY < p->selfHires->height(); thisY++) {
+                    p->selfHires->setPixel(thisX, thisY, color);
+                }
+            }
+        }
+    }
+
     uint8_t pixel[] =
     {
         (uint8_t) clamp<double>(color.red,   0, 255),
@@ -1283,6 +1502,10 @@ bool Bitmap::getRaw(void *output, int output_size)
     
     guardDisposed();
     
+    if (hasHires()) {
+        Debug() << "GAME BUG: Game is calling getRaw on low-res Bitmap; you may want to patch the game to improve graphics quality.";
+    }
+
     if (!p->animation.enabled && (p->surface || p->megaSurface)) {
         void *src = (p->megaSurface) ? p->megaSurface->pixels : p->surface->pixels;
         memcpy(output, src, output_size);
@@ -1300,6 +1523,10 @@ void Bitmap::replaceRaw(void *pixel_data, int size)
     
     GUARD_MEGA;
     
+    if (hasHires()) {
+        Debug() << "GAME BUG: Game is calling replaceRaw on low-res Bitmap; you may want to patch the game to improve graphics quality.";
+    }
+
     int w = width();
     int h = height();
     int requiredsize = w*h*4;
@@ -1318,6 +1545,10 @@ void Bitmap::saveToFile(const char *filename)
 {
     guardDisposed();
     
+    if (hasHires()) {
+        Debug() << "GAME BUG: Game is calling saveToFile on low-res Bitmap; you may want to patch the game to improve graphics quality.";
+    }
+
     SDL_Surface *surf;
     
     if (p->surface || p->megaSurface) {
@@ -1377,6 +1608,11 @@ void Bitmap::hueChange(int hue)
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        p->selfHires->hueChange(hue);
+        return;
+    }
+
     if ((hue % 360) == 0)
         return;
     
@@ -1395,7 +1631,7 @@ void Bitmap::hueChange(int hue)
     
     FBO::bind(newTex.fbo);
     p->pushSetViewport(shader);
-    p->bindTexture(shader);
+    p->bindTexture(shader, false);
     
     p->blitQuad(quad);
     
@@ -1525,6 +1761,26 @@ void Bitmap::drawText(const IntRect &rect, const char *str, int align)
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    if (hasHires()) {
+        Font &loresFont = getFont();
+        Font &hiresFont = p->selfHires->getFont();
+        // Disable the illegal font size check when creating a high-res font.
+        hiresFont.setSize(loresFont.getSize() * p->selfHires->width() / width(), false);
+        hiresFont.setBold(loresFont.getBold());
+        hiresFont.setColor(loresFont.getColor());
+        hiresFont.setItalic(loresFont.getItalic());
+        hiresFont.setShadow(loresFont.getShadow());
+        hiresFont.setOutline(loresFont.getOutline());
+        hiresFont.setOutColor(loresFont.getOutColor());
+
+        int rectX = rect.x * p->selfHires->width() / width();
+        int rectY = rect.y * p->selfHires->height() / height();
+        int rectWidth = rect.w * p->selfHires->width() / width();
+        int rectHeight = rect.h * p->selfHires->height() / height();
+
+        p->selfHires->drawText(IntRect(rectX, rectY, rectWidth, rectHeight), str, align);
+    }
+
     std::string fixed = fixupString(str);
     str = fixed.c_str();
     
@@ -1564,15 +1820,20 @@ void Bitmap::drawText(const IntRect &rect, const char *str, int align)
         SDL_Color co = outColor.toSDLColor();
         co.a = 255;
         SDL_Surface *outline;
+        // Handle high-res for outline.
+        int scaledOutlineSize = OUTLINE_SIZE;
+        if (p->selfLores) {
+            scaledOutlineSize = scaledOutlineSize * width() / p->selfLores->width();
+        }
         /* set the next font render to render the outline */
-        TTF_SetFontOutline(font, OUTLINE_SIZE);
+        TTF_SetFontOutline(font, scaledOutlineSize);
         if (p->font->isSolid())
             outline = TTF_RenderUTF8_Solid(font, str, co);
         else
             outline = TTF_RenderUTF8_Blended(font, str, co);
         
         p->ensureFormat(outline, SDL_PIXELFORMAT_ABGR8888);
-        SDL_Rect outRect = {OUTLINE_SIZE, OUTLINE_SIZE, txtSurf->w, txtSurf->h};
+        SDL_Rect outRect = {scaledOutlineSize, scaledOutlineSize, txtSurf->w, txtSurf->h};
         
         SDL_SetSurfaceBlendMode(txtSurf, SDL_BLENDMODE_BLEND);
         SDL_BlitSurface(txtSurf, NULL, outline, &outRect);
@@ -1787,6 +2048,9 @@ IntRect Bitmap::textSize(const char *str)
     GUARD_MEGA;
     GUARD_ANIMATED;
     
+    // TODO: High-res Bitmap textSize not implemented, but I think it's the same as low-res?
+    // Need to double-check this.
+
     TTF_Font *font = p->font->getSdlFont();
     
     std::string fixed = fixupString(str);
@@ -1811,11 +2075,19 @@ DEF_ATTR_RD_SIMPLE(Bitmap, Font, Font&, *p->font)
 
 void Bitmap::setFont(Font &value)
 {
+    // High-res support handled in drawText, not here.
     *p->font = value;
 }
 
 void Bitmap::setInitFont(Font *value)
 {
+    if (hasHires()) {
+        Font *hiresFont = new Font(*value);
+        // Disable the illegal font size check when creating a high-res font.
+        hiresFont->setSize(hiresFont->getSize() * p->selfHires->width() / width(), false);
+        p->selfHires->setInitFont(hiresFont);
+    }
+
     p->font = value;
 }
 
@@ -1826,11 +2098,24 @@ TEXFBO &Bitmap::getGLTypes() const
 
 SDL_Surface *Bitmap::surface() const
 {
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap surface not implemented";
+    }
+
     return p->surface;
 }
 
 SDL_Surface *Bitmap::megaSurface() const
 {
+    if (hasHires()) {
+        if (p->megaSurface) {
+            Debug() << "BUG: High-res Bitmap megaSurface not implemented (low-res has megaSurface)";
+        }
+        if (p->selfHires->megaSurface()) {
+            Debug() << "BUG: High-res Bitmap megaSurface not implemented (high-res has megaSurface)";
+        }
+    }
+
     return p->megaSurface;
 }
 
@@ -1865,6 +2150,10 @@ void Bitmap::stop()
     GUARD_UNANIMATED;
     if (!p->animation.playing) return;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap stop not implemented";
+    }
+
     p->animation.stop();
 }
 
@@ -1874,6 +2163,11 @@ void Bitmap::play()
     
     GUARD_UNANIMATED;
     if (p->animation.playing) return;
+
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap play not implemented";
+    }
+
     p->animation.play();
 }
 
@@ -1881,6 +2175,10 @@ bool Bitmap::isPlaying() const
 {
     guardDisposed();
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap isPlaying not implemented";
+    }
+
     if (!p->animation.playing)
         return false;
     
@@ -1896,6 +2194,10 @@ void Bitmap::gotoAndStop(int frame)
     
     GUARD_UNANIMATED;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap gotoAndStop not implemented";
+    }
+
     p->animation.stop();
     p->animation.seek(frame);
 }
@@ -1905,6 +2207,10 @@ void Bitmap::gotoAndPlay(int frame)
     
     GUARD_UNANIMATED;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap gotoAndPlay not implemented";
+    }
+
     p->animation.stop();
     p->animation.seek(frame);
     p->animation.play();
@@ -1914,6 +2220,10 @@ int Bitmap::numFrames() const
 {
     guardDisposed();
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap numFrames not implemented";
+    }
+
     if (!p->animation.enabled) return 1;
     return (int)p->animation.frames.size();
 }
@@ -1922,6 +2232,10 @@ int Bitmap::currentFrameI() const
 {
     guardDisposed();
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap currentFrameI not implemented";
+    }
+
     if (!p->animation.enabled) return 0;
     return p->animation.currentFrameI();
 }
@@ -1932,6 +2246,14 @@ int Bitmap::addFrame(Bitmap &source, int position)
     
     GUARD_MEGA;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap addFrame dest not implemented";
+    }
+
+    if (source.hasHires()) {
+        Debug() << "BUG: High-res Bitmap addFrame source not implemented";
+    }
+
     if (source.height() != height() || source.width() != width())
         throw Exception(Exception::MKXPError, "Animations with varying dimensions are not supported (%ix%i vs %ix%i)",
                         source.width(), source.height(), width(), height());
@@ -1989,6 +2311,10 @@ void Bitmap::removeFrame(int position) {
     
     GUARD_UNANIMATED;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap removeFrame not implemented";
+    }
+
     int pos = (position < 0) ? (int)p->animation.frames.size() - 1 : clamp(position, 0, (int)(p->animation.frames.size() - 1));
     shState->texPool().release(p->animation.frames[pos]);
     p->animation.frames.erase(p->animation.frames.begin() + pos);
@@ -2016,6 +2342,10 @@ void Bitmap::nextFrame()
     
     GUARD_UNANIMATED;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap nextFrame not implemented";
+    }
+
     stop();
     if ((uint32_t)p->animation.lastFrame >= p->animation.frames.size() - 1)  {
         if (!p->animation.loop) return;
@@ -2032,6 +2362,10 @@ void Bitmap::previousFrame()
     
     GUARD_UNANIMATED;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap previousFrame not implemented";
+    }
+
     stop();
     if (p->animation.lastFrame <= 0) {
         if (!p->animation.loop) {
@@ -2051,6 +2385,10 @@ void Bitmap::setAnimationFPS(float FPS)
     
     GUARD_MEGA;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap setAnimationFPS not implemented";
+    }
+
     bool restart = p->animation.playing;
     p->animation.stop();
     p->animation.fps = (FPS < 0) ? 0 : FPS;
@@ -2059,6 +2397,10 @@ void Bitmap::setAnimationFPS(float FPS)
 
 std::vector<TEXFBO> &Bitmap::getFrames() const
 {
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap getFrames not implemented";
+    }
+
     return p->animation.frames;
 }
 
@@ -2068,6 +2410,10 @@ float Bitmap::getAnimationFPS() const
     
     GUARD_MEGA;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap getAnimationFPS not implemented";
+    }
+
     return p->animation.fps;
 }
 
@@ -2077,6 +2423,10 @@ void Bitmap::setLooping(bool loop)
     
     GUARD_MEGA;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap setLooping not implemented";
+    }
+
     p->animation.loop = loop;
 }
 
@@ -2086,16 +2436,32 @@ bool Bitmap::getLooping() const
     
     GUARD_MEGA;
     
+    if (hasHires()) {
+        Debug() << "BUG: High-res Bitmap getLooping not implemented";
+    }
+
     return p->animation.loop;
 }
 
 void Bitmap::bindTex(ShaderBase &shader)
 {
+    // Hires mode is handled by p->bindTexture.
+
     p->bindTexture(shader);
 }
 
 void Bitmap::taintArea(const IntRect &rect)
 {
+    if (hasHires()) {
+        int destX, destY, destWidth, destHeight;
+        destX = rect.x * p->selfHires->width() / width();
+        destY = rect.y * p->selfHires->height() / height();
+        destWidth = rect.w * p->selfHires->width() / width();
+        destHeight = rect.h * p->selfHires->height() / height();
+
+        p->selfHires->taintArea(IntRect(destX, destY, destWidth, destHeight));
+    }
+
     p->addTaintedArea(rect);
 }
 
@@ -2121,8 +2487,17 @@ bool Bitmap::invalid() const {
     return p == 0;
 }
 
+void Bitmap::assumeRubyGC()
+{
+    p->assumingRubyGC = true;
+}
+
 void Bitmap::releaseResources()
 {
+    if (p->selfHires && !p->assumingRubyGC) {
+        delete p->selfHires;
+    }
+
     if (p->megaSurface)
         SDL_FreeSurface(p->megaSurface);
     else if (p->animation.enabled) {
diff --git a/src/display/bitmap.h b/src/display/bitmap.h
index 6ca72c13..44760bb6 100644
--- a/src/display/bitmap.h
+++ b/src/display/bitmap.h
@@ -39,7 +39,7 @@ class Bitmap : public Disposable
 {
 public:
 	Bitmap(const char *filename);
-	Bitmap(int width, int height);
+	Bitmap(int width, int height, bool isHires = false);
     Bitmap(void *pixeldata, int width, int height);
 	/* Clone constructor */
     
@@ -49,6 +49,9 @@ public:
 
 	int width()  const;
 	int height() const;
+	bool hasHires() const;
+	DECL_ATTR(Hires, Bitmap*)
+	void setLores(Bitmap *lores);
 	bool isMega() const;
     bool isAnimated() const;
 
@@ -161,6 +164,8 @@ public:
     
     bool invalid() const;
 
+    void assumeRubyGC();
+
 private:
 	void releaseResources();
 	const char *klassName() const { return "bitmap"; }
diff --git a/src/display/font.cpp b/src/display/font.cpp
index 98d4033e..d0aa8d4b 100644
--- a/src/display/font.cpp
+++ b/src/display/font.cpp
@@ -399,14 +399,17 @@ void Font::setName(const std::vector<std::string> &names)
 	p->sdlFont = 0;
 }
 
-void Font::setSize(int value)
+void Font::setSize(int value, bool checkIllegal)
 {
 	if (p->size == value)
 		return;
 
 	/* Catch illegal values (according to RMXP) */
-	if (value < 6 || value > 96)
-		throw Exception(Exception::ArgumentError, "%s", "bad value for size");
+	if (value < 6 || value > 96) {
+		if (checkIllegal) {
+			throw Exception(Exception::ArgumentError, "%s", "bad value for size");
+		}
+	}
 
 	p->size = value;
 	p->sdlFont = 0;
diff --git a/src/display/font.h b/src/display/font.h
index f76b8421..fe7d9751 100644
--- a/src/display/font.h
+++ b/src/display/font.h
@@ -76,7 +76,9 @@ public:
 
 	const Font &operator=(const Font &o);
 
-	DECL_ATTR( Size,     int    )
+	int getSize() const;
+	void setSize(int value, bool checkIllegal=true);
+
 	DECL_ATTR( Bold,     bool   )
 	DECL_ATTR( Italic,   bool   )
 	DECL_ATTR( Color,    Color& )
diff --git a/src/display/gl/gl-meta.cpp b/src/display/gl/gl-meta.cpp
index 1f39dc8d..f80050c1 100644
--- a/src/display/gl/gl-meta.cpp
+++ b/src/display/gl/gl-meta.cpp
@@ -26,6 +26,11 @@
 #include "quad.h"
 #include "config.h"
 
+namespace FBO
+{
+	ID boundFramebufferID;
+}
+
 namespace GLMeta
 {
 
@@ -138,6 +143,7 @@ static void _blitBegin(FBO::ID fbo, const Vec2i &size)
 {
 	if (HAVE_NATIVE_BLIT)
 	{
+		FBO::boundFramebufferID = fbo;
 		gl.BindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo.gl);
 	}
 	else
@@ -164,18 +170,56 @@ static void _blitBegin(FBO::ID fbo, const Vec2i &size)
 	}
 }
 
-void blitBegin(TEXFBO &target)
+int blitDstWidthLores = 1;
+int blitDstWidthHires = 1;
+int blitDstHeightLores = 1;
+int blitDstHeightHires = 1;
+
+int blitSrcWidthLores = 1;
+int blitSrcWidthHires = 1;
+int blitSrcHeightLores = 1;
+int blitSrcHeightHires = 1;
+
+void blitBegin(TEXFBO &target, bool preferHires)
 {
-	_blitBegin(target.fbo, Vec2i(target.width, target.height));
+	blitDstWidthLores = target.width;
+	blitDstHeightLores = target.height;
+
+	if (preferHires && target.selfHires != nullptr) {
+		blitDstWidthHires = target.selfHires->width;
+		blitDstHeightHires = target.selfHires->height;
+		_blitBegin(target.selfHires->fbo, Vec2i(target.selfHires->width, target.selfHires->height));
+	}
+	else {
+		blitDstWidthHires = blitDstWidthLores;
+		blitDstHeightHires = blitDstHeightLores;
+		_blitBegin(target.fbo, Vec2i(target.width, target.height));
+	}
 }
 
 void blitBeginScreen(const Vec2i &size)
 {
+	blitDstWidthLores = 1;
+	blitDstWidthHires = 1;
+	blitDstHeightLores = 1;
+	blitDstHeightHires = 1;
+
 	_blitBegin(FBO::ID(0), size);
 }
 
 void blitSource(TEXFBO &source)
 {
+	blitSrcWidthLores = source.width;
+	blitSrcHeightLores = source.height;
+	if (source.selfHires != nullptr) {
+		blitSrcWidthHires = source.selfHires->width;
+		blitSrcHeightHires = source.selfHires->height;
+	}
+	else {
+		blitSrcWidthHires = blitSrcWidthLores;
+		blitSrcHeightHires = blitSrcHeightLores;
+	}
+
 	if (HAVE_NATIVE_BLIT)
 	{
 		gl.BindFramebuffer(GL_READ_FRAMEBUFFER, source.fbo.gl);
@@ -186,15 +230,20 @@ void blitSource(TEXFBO &source)
 		{
 			Lanczos3Shader &shader = shState->shaders().lanczos3;
 			shader.bind();
-			shader.setTexSize(Vec2i(source.width, source.height));
+			shader.setTexSize(Vec2i(blitSrcWidthHires, blitSrcHeightHires));
 		}
 		else
 		{
 			SimpleShader &shader = shState->shaders().simple;
 			shader.bind();
-			shader.setTexSize(Vec2i(source.width, source.height));
+			shader.setTexSize(Vec2i(blitSrcWidthHires, blitSrcHeightHires));
+		}
+		if (source.selfHires != nullptr) {
+			TEX::bind(source.selfHires->tex);
+		}
+		else {
+			TEX::bind(source.tex);
 		}
-		TEX::bind(source.tex);
 	}
 }
 
@@ -205,10 +254,24 @@ void blitRectangle(const IntRect &src, const Vec2i &dstPos)
 
 void blitRectangle(const IntRect &src, const IntRect &dst, bool smooth)
 {
+	// Handle high-res dest
+	int scaledDstX = dst.x * blitDstWidthHires / blitDstWidthLores;
+	int scaledDstY = dst.y * blitDstHeightHires / blitDstHeightLores;
+	int scaledDstWidth = dst.w * blitDstWidthHires / blitDstWidthLores;
+	int scaledDstHeight = dst.h * blitDstHeightHires / blitDstHeightLores;
+	IntRect dstScaled(scaledDstX, scaledDstY, scaledDstWidth, scaledDstHeight);
+
+	// Handle high-res source
+	int scaledSrcX = src.x * blitSrcWidthHires / blitSrcWidthLores;
+	int scaledSrcY = src.y * blitSrcHeightHires / blitSrcHeightLores;
+	int scaledSrcWidth = src.w * blitSrcWidthHires / blitSrcWidthLores;
+	int scaledSrcHeight = src.h * blitSrcHeightHires / blitSrcHeightLores;
+	IntRect srcScaled(scaledSrcX, scaledSrcY, scaledSrcWidth, scaledSrcHeight);
+
 	if (HAVE_NATIVE_BLIT)
 	{
-		gl.BlitFramebuffer(src.x, src.y, src.x+src.w, src.y+src.h,
-		                   dst.x, dst.y, dst.x+dst.w, dst.y+dst.h,
+		gl.BlitFramebuffer(srcScaled.x, srcScaled.y, srcScaled.x+srcScaled.w, srcScaled.y+srcScaled.h,
+		                   dstScaled.x, dstScaled.y, dstScaled.x+dstScaled.w, dstScaled.y+dstScaled.h,
 		                   GL_COLOR_BUFFER_BIT, smooth ? GL_LINEAR : GL_NEAREST);
 	}
 	else
@@ -218,7 +281,7 @@ void blitRectangle(const IntRect &src, const IntRect &dst, bool smooth)
 
 		glState.blend.pushSet(false);
 		Quad &quad = shState->gpQuad();
-		quad.setTexPosRect(src, dst);
+		quad.setTexPosRect(srcScaled, dstScaled);
 		quad.draw();
 		glState.blend.pop();
 
@@ -229,8 +292,19 @@ void blitRectangle(const IntRect &src, const IntRect &dst, bool smooth)
 
 void blitEnd()
 {
-	if (!HAVE_NATIVE_BLIT)
+	blitDstWidthLores = 1;
+	blitDstWidthHires = 1;
+	blitDstHeightLores = 1;
+	blitDstHeightHires = 1;
+
+	blitSrcWidthLores = 1;
+	blitSrcWidthHires = 1;
+	blitSrcHeightLores = 1;
+	blitSrcHeightHires = 1;
+
+	if (!HAVE_NATIVE_BLIT) {
 		glState.viewport.pop();
+	}
 }
 
 }
diff --git a/src/display/gl/gl-meta.h b/src/display/gl/gl-meta.h
index fd8cf8ab..13ef1ffd 100644
--- a/src/display/gl/gl-meta.h
+++ b/src/display/gl/gl-meta.h
@@ -65,7 +65,7 @@ void vaoBind(VAO &vao);
 void vaoUnbind(VAO &vao);
 
 /* EXT_framebuffer_blit */
-void blitBegin(TEXFBO &target);
+void blitBegin(TEXFBO &target, bool preferHires = false);
 void blitBeginScreen(const Vec2i &size);
 void blitSource(TEXFBO &source);
 void blitRectangle(const IntRect &src, const Vec2i &dstPos);
diff --git a/src/display/gl/gl-util.h b/src/display/gl/gl-util.h
index 945af787..212040e2 100644
--- a/src/display/gl/gl-util.h
+++ b/src/display/gl/gl-util.h
@@ -109,6 +109,8 @@ namespace FBO
 {
 	DEF_GL_ID
 
+	extern ID boundFramebufferID;
+
 	inline ID gen()
 	{
 		ID id;
@@ -124,6 +126,7 @@ namespace FBO
 
 	static inline void bind(ID id)
 	{
+		boundFramebufferID = id;
 		gl.BindFramebuffer(GL_FRAMEBUFFER, id.gl);
 	}
 
@@ -203,8 +206,10 @@ struct TEXFBO
 	FBO::ID fbo;
 	int width, height;
 
+	TEXFBO *selfHires;
+
 	TEXFBO()
-	    : tex(0), fbo(0), width(0), height(0)
+	    : tex(0), fbo(0), width(0), height(0), selfHires(nullptr)
 	{}
 
 	bool operator==(const TEXFBO &other) const
diff --git a/src/display/gl/glstate.cpp b/src/display/gl/glstate.cpp
index 6bf78d74..d021d887 100644
--- a/src/display/gl/glstate.cpp
+++ b/src/display/gl/glstate.cpp
@@ -23,7 +23,9 @@
 #include "config.h"
 #include "etc.h"
 #include "gl-fun.h"
+#include "graphics.h"
 #include "shader.h"
+#include "sharedstate.h"
 
 #include <SDL_rect.h>
 
@@ -36,7 +38,19 @@ void GLClearColor::apply(const Vec4 &value) {
 }
 
 void GLScissorBox::apply(const IntRect &value) {
-  gl.Scissor(value.x, value.y, value.w, value.h);
+  // High-res: scale the scissorbox if we're rendering to the PingPong framebuffer.
+  if (shState) {
+    const double framebufferScalingFactor = shState->config().framebufferScalingFactor;
+    if (shState->config().enableHires && shState->graphics().isPingPongFramebufferActive()) {
+      gl.Scissor((int)lround(framebufferScalingFactor * value.x), (int)lround(framebufferScalingFactor * value.y), (int)lround(framebufferScalingFactor * value.w), (int)lround(framebufferScalingFactor * value.h));
+    }
+    else {
+      gl.Scissor(value.x, value.y, value.w, value.h);
+    }
+  }
+  else {
+    gl.Scissor(value.x, value.y, value.w, value.h);
+  }
 }
 
 void GLScissorBox::setIntersect(const IntRect &value) {
diff --git a/src/display/gl/quad.h b/src/display/gl/quad.h
index d200c6b5..ecff83e4 100644
--- a/src/display/gl/quad.h
+++ b/src/display/gl/quad.h
@@ -22,6 +22,8 @@
 #ifndef QUAD_H
 #define QUAD_H
 
+#include "config.h"
+#include "graphics.h"
 #include "vertex.h"
 #include "gl-util.h"
 #include "gl-meta.h"
diff --git a/src/display/gl/shader.cpp b/src/display/gl/shader.cpp
index 53aea311..28bb2ed0 100644
--- a/src/display/gl/shader.cpp
+++ b/src/display/gl/shader.cpp
@@ -20,6 +20,8 @@
 */
 
 #include "shader.h"
+#include "config.h"
+#include "graphics.h"
 #include "sharedstate.h"
 #include "glstate.h"
 #include "exception.h"
@@ -293,8 +295,19 @@ void ShaderBase::init()
 
 void ShaderBase::applyViewportProj()
 {
+	// High-res: scale the matrix if we're rendering to the PingPong framebuffer.
 	const IntRect &vp = glState.viewport.get();
-	projMat.set(Vec2i(vp.w, vp.h));
+	if (shState->config().enableHires && shState->graphics().isPingPongFramebufferActive() && framebufferScalingAllowed()) {
+		projMat.set(Vec2i(shState->graphics().width(), shState->graphics().height()));
+	}
+	else {
+		projMat.set(Vec2i(vp.w, vp.h));
+	}
+}
+
+bool ShaderBase::framebufferScalingAllowed()
+{
+	return true;
 }
 
 void ShaderBase::setTexSize(const Vec2i &value)
@@ -593,6 +606,13 @@ GrayShader::GrayShader()
 	GET_U(gray);
 }
 
+bool GrayShader::framebufferScalingAllowed()
+{
+	// This shader is used with input textures that have already had a
+	// framebuffer scale applied. So we don't want to double-apply it.
+	return false;
+}
+
 void GrayShader::setGray(float value)
 {
 	gl.Uniform1f(u_gray, value);
diff --git a/src/display/gl/shader.h b/src/display/gl/shader.h
index aeec2cfb..fd79dfbc 100644
--- a/src/display/gl/shader.h
+++ b/src/display/gl/shader.h
@@ -91,6 +91,7 @@ public:
 
 protected:
 	void init();
+	virtual bool framebufferScalingAllowed();
 
 	GLint u_texSizeInv, u_translation;
 };
@@ -226,6 +227,9 @@ public:
 
 	void setGray(float value);
 
+protected:
+	virtual bool framebufferScalingAllowed();
+
 private:
 	GLint u_gray;
 };
diff --git a/src/display/gl/tileatlasvx.cpp b/src/display/gl/tileatlasvx.cpp
index 116fc305..aa6a78f8 100644
--- a/src/display/gl/tileatlasvx.cpp
+++ b/src/display/gl/tileatlasvx.cpp
@@ -24,6 +24,7 @@
 #include "tilemap-common.h"
 #include "bitmap.h"
 #include "table.h"
+#include "debugwriter.h"
 #include "etc-internal.h"
 #include "gl-util.h"
 #include "gl-meta.h"
@@ -273,7 +274,7 @@ void build(TEXFBO &tf, Bitmap *bitmaps[BM_COUNT])
 {
 	assert(tf.width == ATLASVX_W && tf.height == ATLASVX_H);
 
-	GLMeta::blitBegin(tf);
+	GLMeta::blitBegin(tf, true);
 
 	glState.clearColor.pushSet(Vec4());
 	FBO::clear();
@@ -282,13 +283,36 @@ void build(TEXFBO &tf, Bitmap *bitmaps[BM_COUNT])
 	if (rgssVer >= 3)
 	{
 		SDL_Surface *shadow = createShadowSet();
-		TEX::bind(tf.tex);
-		TEX::uploadSubImage(shadowArea.x*32, shadowArea.y*32,
-							shadow->w, shadow->h, shadow->pixels, GL_RGBA);
+		if (tf.selfHires != nullptr) {
+			SDL_Rect srcRect({0, 0, shadow->w, shadow->h});
+			int destX = shadowArea.x*32 * tf.selfHires->width / tf.width;
+			int destY = shadowArea.y*32 * tf.selfHires->height / tf.height;
+			int destWidth = shadow->w * tf.selfHires->width / tf.width;
+			int destHeight = shadow->h * tf.selfHires->height / tf.height;
+
+			int bpp;
+			Uint32 rMask, gMask, bMask, aMask;
+			SDL_PixelFormatEnumToMasks(SDL_PIXELFORMAT_ABGR8888,
+			                           &bpp, &rMask, &gMask, &bMask, &aMask);
+			SDL_Surface *blitTemp =
+				SDL_CreateRGBSurface(0, destWidth, destHeight, bpp, rMask, gMask, bMask, aMask);
+
+			SDL_BlitScaled(shadow, &srcRect, blitTemp, 0);
+
+			TEX::bind(tf.selfHires->tex);
+			TEX::uploadSubImage(destX, destY,
+				blitTemp->w, blitTemp->h, blitTemp->pixels, GL_RGBA);
+		}
+		else {
+			TEX::bind(tf.tex);
+			TEX::uploadSubImage(shadowArea.x*32, shadowArea.y*32,
+				shadow->w, shadow->h, shadow->pixels, GL_RGBA);
+		}
 		SDL_FreeSurface(shadow);
 	}
 
 	Bitmap *bm;
+
 #define EXEC_BLITS(part) \
 	if (!nullOrDisposed(bm = bitmaps[BM_##part])) \
 	{ \
diff --git a/src/display/graphics.cpp b/src/display/graphics.cpp
index 366fe980..2a9fe935 100644
--- a/src/display/graphics.cpp
+++ b/src/display/graphics.cpp
@@ -772,6 +772,7 @@ struct GraphicsPrivate {
      * RGSS renders at (settable with Graphics.resize_screen).
      * Can only be changed from within RGSS */
     Vec2i scRes;
+    Vec2i scResLores;
     
     /* Screen size, to which the rendered frames are scaled up.
      * This can be smaller than the window size when fixed aspect
@@ -828,7 +829,7 @@ struct GraphicsPrivate {
     IntruList<Disposable> dispList;
     
     GraphicsPrivate(RGSSThreadData *rtData)
-    : scRes(DEF_SCREEN_W, DEF_SCREEN_H), scSize(scRes),
+    : scRes(DEF_SCREEN_W, DEF_SCREEN_H), scResLores(scRes), scSize(scRes),
     winSize(rtData->config.defScreenW, rtData->config.defScreenH),
     screen(scRes.x, scRes.y), threadData(rtData),
     glCtx(SDL_GL_GetCurrentContext()), multithreadedMode(true),
@@ -999,11 +1000,15 @@ struct GraphicsPrivate {
     }
     
     void compositeToBuffer(TEXFBO &buffer) {
+        compositeToBufferScaled(buffer, scRes.x, scRes.y);
+    }
+
+    void compositeToBufferScaled(TEXFBO &buffer, int destWidth, int destHeight) {
         screen.composite();
         
         GLMeta::blitBegin(buffer);
         GLMeta::blitSource(screen.getPP().frontBuffer());
-        GLMeta::blitRectangle(IntRect(0, 0, scRes.x, scRes.y), Vec2i());
+        GLMeta::blitRectangle(IntRect(0, 0, scRes.x, scRes.y), IntRect(0, 0, destWidth, destHeight));
         GLMeta::blitEnd();
     }
     
@@ -1229,22 +1234,28 @@ void Graphics::transition(int duration, const char *filename, int vague) {
     TransShader &transShader = shState->shaders().trans;
     SimpleTransShader &simpleShader = shState->shaders().simpleTrans;
     
+    // Handle high-res.
+    Vec2i transSize(p->scResLores.x, p->scResLores.y);
+
     if (transMap) {
         TransShader &shader = transShader;
         shader.bind();
         shader.applyViewportProj();
         shader.setFrozenScene(p->frozenScene.tex);
         shader.setCurrentScene(currentScene.tex);
+        if (transMap->hasHires()) {
+            Debug() << "BUG: High-res Graphics transMap not implemented";
+        }
         shader.setTransMap(transMap->getGLTypes().tex);
         shader.setVague(vague / 256.0f);
-        shader.setTexSize(p->scRes);
+        shader.setTexSize(transSize);
     } else {
         SimpleTransShader &shader = simpleShader;
         shader.bind();
         shader.applyViewportProj();
         shader.setFrozenScene(p->frozenScene.tex);
         shader.setCurrentScene(currentScene.tex);
-        shader.setTexSize(p->scRes);
+        shader.setTexSize(transSize);
     }
     
     glState.blend.pushSet(false);
@@ -1391,16 +1402,36 @@ void Graphics::fadein(int duration) {
 Bitmap *Graphics::snapToBitmap() {
     Bitmap *bitmap = new Bitmap(width(), height());
     
-    p->compositeToBuffer(bitmap->getGLTypes());
+    if (bitmap->hasHires()) {
+        p->compositeToBufferScaled(bitmap->getHires()->getGLTypes(), bitmap->getHires()->width(), bitmap->getHires()->height());
+    }
+
+    p->compositeToBufferScaled(bitmap->getGLTypes(), bitmap->width(), bitmap->height());
     
     /* Taint entire bitmap */
     bitmap->taintArea(IntRect(0, 0, width(), height()));
     return bitmap;
 }
 
-int Graphics::width() const { return p->scRes.x; }
+int Graphics::width() const { return p->scResLores.x; }
 
-int Graphics::height() const { return p->scRes.y; }
+int Graphics::height() const { return p->scResLores.y; }
+
+int Graphics::widthHires() const { return p->scRes.x; }
+
+int Graphics::heightHires() const { return p->scRes.y; }
+
+bool Graphics::isPingPongFramebufferActive() const {
+    return p->screen.getPP().frontBuffer().fbo == FBO::boundFramebufferID || p->screen.getPP().backBuffer().fbo == FBO::boundFramebufferID;
+}
+
+int Graphics::displayContentWidth() const {
+    return p->scSize.x;
+}
+
+int Graphics::displayContentHeight() const {
+    return p->scSize.y;
+}
 
 int Graphics::displayWidth() const {
     SDL_DisplayMode dm{};
@@ -1418,12 +1449,21 @@ void Graphics::resizeScreen(int width, int height) {
     p->threadData->rqWindowAdjust.wait();
     p->checkResize(true);
     
+    Vec2i sizeLores(width, height);
+
+    if (shState->config().enableHires) {
+        double framebufferScalingFactor = shState->config().framebufferScalingFactor;
+        width = (int)lround(framebufferScalingFactor * width);
+        height = (int)lround(framebufferScalingFactor * height);
+    }
+
     Vec2i size(width, height);
     
     if (p->scRes == size)
         return;
     
     p->scRes = size;
+    p->scResLores = sizeLores;
     
     p->screen.setResolution(width, height);
     
@@ -1459,6 +1499,10 @@ bool Graphics::updateMovieInput(Movie *movie) {
 }
 
 void Graphics::playMovie(const char *filename, int volume_, bool skippable) {
+    if (shState->config().enableHires) {
+        Debug() << "BUG: High-res Graphics playMovie not implemented";
+    }
+
     Movie *movie = new Movie(skippable);
     MovieOpenHandler handler(movie->srcOps);
     shState->fileSystem().openRead(handler, filename);
diff --git a/src/display/graphics.h b/src/display/graphics.h
index 90bcd74a..130478f3 100644
--- a/src/display/graphics.h
+++ b/src/display/graphics.h
@@ -58,6 +58,11 @@ public:
 
 	int width() const;
 	int height() const;
+	int widthHires() const;
+	int heightHires() const;
+	bool isPingPongFramebufferActive() const;
+    int displayContentWidth() const;
+    int displayContentHeight() const;
     int displayWidth() const;
     int displayHeight() const;
 	void resizeScreen(int width, int height);
diff --git a/src/display/sprite.cpp b/src/display/sprite.cpp
index 5c76297d..5b7a3766 100644
--- a/src/display/sprite.cpp
+++ b/src/display/sprite.cpp
@@ -23,6 +23,7 @@
 
 #include "sharedstate.h"
 #include "bitmap.h"
+#include "debugwriter.h"
 #include "etc.h"
 #include "etc-internal.h"
 #include "util.h"
@@ -605,6 +606,10 @@ void Sprite::draw()
         shader.setBushOpacity(p->bushOpacity.norm);
         
         if (p->pattern && p->patternOpacity > 0) {
+            if (p->pattern->hasHires()) {
+                Debug() << "BUG: High-res Sprite pattern not implemented";
+            }
+
             shader.setPattern(p->pattern->getGLTypes().tex, Vec2(p->pattern->width(), p->pattern->height()));
             shader.setPatternBlendType(p->patternBlendType);
             shader.setPatternTile(p->patternTile);
diff --git a/src/display/tilemap.cpp b/src/display/tilemap.cpp
index 2cd30c46..bc2da7df 100644
--- a/src/display/tilemap.cpp
+++ b/src/display/tilemap.cpp
@@ -27,6 +27,7 @@
 
 #include "sharedstate.h"
 #include "config.h"
+#include "debugwriter.h"
 #include "glstate.h"
 #include "gl-util.h"
 #include "gl-meta.h"
@@ -550,6 +551,10 @@ struct TilemapPrivate
 			int blitW = std::min(atW, atAreaW);
 			int blitH = std::min(atH, autotileH);
 
+			if (autotile->hasHires()) {
+				Debug() << "BUG: High-res Tilemap blit autotiles not implemented";
+			}
+
 			GLMeta::blitSource(autotile->getGLTypes());
 
 			if (atW <= autotileW && tiles.animated && !atlas.smallATs[atInd])
@@ -639,6 +644,10 @@ struct TilemapPrivate
 		}
 		else
 		{
+			if (tileset->hasHires()) {
+				Debug() << "BUG: High-res Tilemap regular tileset not implemented";
+			}
+
 			/* Regular tileset */
 			GLMeta::blitBegin(atlas.gl);
 			GLMeta::blitSource(tileset->getGLTypes());
diff --git a/src/display/tilemapvx.cpp b/src/display/tilemapvx.cpp
index 6dfe2849..678f1a60 100644
--- a/src/display/tilemapvx.cpp
+++ b/src/display/tilemapvx.cpp
@@ -72,6 +72,8 @@ struct TilemapVXPrivate : public ViewportElement, TileAtlasVX::Reader
 	VBO::ID vbo;
 	GLMeta::VAO vao;
 
+	TEXFBO atlasHires;
+
 	size_t allocQuads;
 
 	size_t groundQuads;
@@ -132,6 +134,14 @@ struct TilemapVXPrivate : public ViewportElement, TileAtlasVX::Reader
 
 		shState->requestAtlasTex(ATLASVX_W, ATLASVX_H, atlas);
 
+		if (shState->config().enableHires) {
+			double scalingFactor = shState->config().atlasScalingFactor;
+			int hiresWidth = (int)lround(scalingFactor * ATLASVX_W);
+			int hiresHeight = (int)lround(scalingFactor * ATLASVX_H);
+			shState->requestAtlasTex(hiresWidth, hiresHeight, atlasHires);
+			atlas.selfHires = &atlasHires;
+		}
+
 		vbo = VBO::gen();
 
 		GLMeta::vaoFillInVertexData<SVertex>(vao);
@@ -151,6 +161,9 @@ struct TilemapVXPrivate : public ViewportElement, TileAtlasVX::Reader
 		VBO::del(vbo);
 
 		shState->releaseAtlasTex(atlas);
+		if (shState->config().enableHires) {
+			shState->releaseAtlasTex(atlasHires);
+		}
 
 		prepareCon.disconnect();
 
@@ -310,7 +323,12 @@ struct TilemapVXPrivate : public ViewportElement, TileAtlasVX::Reader
 		shader->applyViewportProj();
 		shader->setTranslation(dispPos);
 
-		TEX::bind(atlas.tex);
+		if (atlas.selfHires != nullptr) {
+			TEX::bind(atlas.selfHires->tex);
+		}
+		else {
+			TEX::bind(atlas.tex);
+		}
 		GLMeta::vaoBind(vao);
 
 		gl.DrawElements(GL_TRIANGLES, groundQuads*6, _GL_INDEX_TYPE, 0);
@@ -329,7 +347,12 @@ struct TilemapVXPrivate : public ViewportElement, TileAtlasVX::Reader
 		shader.applyViewportProj();
 		shader.setTranslation(dispPos);
 
-		TEX::bind(atlas.tex);
+		if (atlas.selfHires != nullptr) {
+			TEX::bind(atlas.selfHires->tex);
+		}
+		else {
+			TEX::bind(atlas.tex);
+		}
 		GLMeta::vaoBind(vao);
 
 		gl.DrawElements(GL_TRIANGLES, aboveQuads*6, _GL_INDEX_TYPE,
diff --git a/tests/hires-bitmap/Graphics/Pictures/children-alpha-lo.jxl b/tests/hires-bitmap/Graphics/Pictures/children-alpha-lo.jxl
new file mode 100644
index 00000000..69fa96e3
Binary files /dev/null and b/tests/hires-bitmap/Graphics/Pictures/children-alpha-lo.jxl differ
diff --git a/tests/hires-bitmap/Graphics/Pictures/children-alpha.jxl b/tests/hires-bitmap/Graphics/Pictures/children-alpha.jxl
new file mode 100644
index 00000000..69fa96e3
Binary files /dev/null and b/tests/hires-bitmap/Graphics/Pictures/children-alpha.jxl differ
diff --git a/tests/hires-bitmap/Graphics/Pictures/tree_alpha_16bit-lo.jxl b/tests/hires-bitmap/Graphics/Pictures/tree_alpha_16bit-lo.jxl
new file mode 100644
index 00000000..f2640c59
Binary files /dev/null and b/tests/hires-bitmap/Graphics/Pictures/tree_alpha_16bit-lo.jxl differ
diff --git a/tests/hires-bitmap/Graphics/Pictures/tree_alpha_16bit.jxl b/tests/hires-bitmap/Graphics/Pictures/tree_alpha_16bit.jxl
new file mode 100644
index 00000000..f2640c59
Binary files /dev/null and b/tests/hires-bitmap/Graphics/Pictures/tree_alpha_16bit.jxl differ
diff --git a/tests/hires-bitmap/Hires/Graphics/Pictures/children-alpha.jxl b/tests/hires-bitmap/Hires/Graphics/Pictures/children-alpha.jxl
new file mode 100644
index 00000000..c70c55d8
Binary files /dev/null and b/tests/hires-bitmap/Hires/Graphics/Pictures/children-alpha.jxl differ
diff --git a/tests/hires-bitmap/Hires/Graphics/Pictures/tree_alpha_16bit.jxl b/tests/hires-bitmap/Hires/Graphics/Pictures/tree_alpha_16bit.jxl
new file mode 100644
index 00000000..bd0ce9d4
Binary files /dev/null and b/tests/hires-bitmap/Hires/Graphics/Pictures/tree_alpha_16bit.jxl differ
diff --git a/tests/hires-bitmap/hires-bitmap-test.rb b/tests/hires-bitmap/hires-bitmap-test.rb
new file mode 100755
index 00000000..3a62d0f9
--- /dev/null
+++ b/tests/hires-bitmap/hires-bitmap-test.rb
@@ -0,0 +1,412 @@
+# Test suite for mkxp-z high-res Bitmap replacement.
+# Bitmap tests.
+# Copyright 2023 Splendide Imaginarius.
+# License GPLv2+.
+# Test images are from https://github.com/xinntao/Real-ESRGAN/
+#
+# Run the suite via the "customScript" field in mkxp.json.
+# Use RGSS v3 for best results.
+
+def dump(bmp, spr, desc)
+	spr.bitmap = bmp
+	Graphics.wait(1)
+	bmp.to_file("test-results/" + desc + "-lo.png")
+	if !bmp.hires.nil?
+		bmp.hires.to_file("test-results/" + desc + "-hi.png")
+	end
+	System::puts("Finished " + desc)
+end
+
+# Setup graphics
+Graphics.resize_screen(640, 480)
+
+# Setup font
+fnt = Font.new("Liberation Sans", 100)
+
+# Setup splash screen
+bmp = Bitmap.new(640, 480)
+bmp.fill_rect(0, 0, 640, 480, Color.new(0, 0, 0))
+
+bmp.font = fnt
+bmp.draw_text(0, 0, 640, 240, "High-Res Test Suite", 1)
+bmp.draw_text(0, 240, 640, 240, "Starting Now", 1)
+
+spr = Sprite.new()
+spr.bitmap = bmp
+
+Graphics.wait(1 * 60)
+
+# Tests start here
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha")
+dump(bmp, spr, "constructor-filename")
+
+# TODO: Filename GIF constructor
+
+bmp = Bitmap.new(640, 480)
+bmp.clear
+dump(bmp, spr, "constructor-dimensions")
+
+# TODO: Animation constructor
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.clear
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect)
+dump(bmp, spr, "stretch-blt-clear-tree-lo-children-full-opaque")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.clear
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect, 127)
+dump(bmp, spr, "stretch-blt-clear-tree-lo-children-full-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.clear
+rect = bmp.rect
+rect.width /= 2
+rect.height /= 2
+rect.x = rect.width
+rect.y = rect.height
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+rect2 = bmp2.rect
+rect2.width /= 2
+rect2.height /= 2
+rect2.x = rect2.width
+bmp.stretch_blt(rect, bmp2, rect2, 127)
+dump(bmp, spr, "stretch-blt-clear-tree-lo-children-quarter-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.clear
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect)
+dump(bmp, spr, "stretch-blt-clear-tree-hi-children-full-opaque")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.clear
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect, 127)
+dump(bmp, spr, "stretch-blt-clear-tree-hi-children-full-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.clear
+rect = bmp.rect
+rect.width /= 2
+rect.height /= 2
+rect.x = rect.width
+rect.y = rect.height
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+rect2 = bmp2.rect
+rect2.width /= 2
+rect2.height /= 2
+rect2.x = rect2.width
+bmp.stretch_blt(rect, bmp2, rect2, 127)
+dump(bmp, spr, "stretch-blt-clear-tree-hi-children-quarter-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.fill_rect(bmp.rect, Color.new(0, 0, 0))
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect)
+dump(bmp, spr, "stretch-blt-black-tree-lo-children-full-opaque")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.fill_rect(bmp.rect, Color.new(0, 0, 0))
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect, 127)
+dump(bmp, spr, "stretch-blt-black-tree-lo-children-full-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.fill_rect(bmp.rect, Color.new(0, 0, 0))
+rect = bmp.rect
+rect.width /= 2
+rect.height /= 2
+rect.x = rect.width
+rect.y = rect.height
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+rect2 = bmp2.rect
+rect2.width /= 2
+rect2.height /= 2
+rect2.x = rect2.width
+bmp.stretch_blt(rect, bmp2, rect2, 127)
+dump(bmp, spr, "stretch-blt-black-tree-lo-children-quarter-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.fill_rect(bmp.rect, Color.new(0, 0, 0))
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect)
+dump(bmp, spr, "stretch-blt-black-tree-hi-children-full-opaque")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.fill_rect(bmp.rect, Color.new(0, 0, 0))
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect, 127)
+dump(bmp, spr, "stretch-blt-black-tree-hi-children-full-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp.fill_rect(bmp.rect, Color.new(0, 0, 0))
+rect = bmp.rect
+rect.width /= 2
+rect.height /= 2
+rect.x = rect.width
+rect.y = rect.height
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+rect2 = bmp2.rect
+rect2.width /= 2
+rect2.height /= 2
+rect2.x = rect2.width
+bmp.stretch_blt(rect, bmp2, rect2, 127)
+dump(bmp, spr, "stretch-blt-black-tree-hi-children-quarter-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit-lo")
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect)
+dump(bmp, spr, "stretch-blt-lo-tree-lo-children-full-opaque")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit-lo")
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect, 127)
+dump(bmp, spr, "stretch-blt-lo-tree-lo-children-full-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit-lo")
+rect = bmp.rect
+rect.width /= 2
+rect.height /= 2
+rect.x = rect.width
+rect.y = rect.height
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+rect2 = bmp2.rect
+rect2.width /= 2
+rect2.height /= 2
+rect2.x = rect2.width
+bmp.stretch_blt(rect, bmp2, rect2, 127)
+dump(bmp, spr, "stretch-blt-lo-tree-lo-children-quarter-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit-lo")
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect)
+dump(bmp, spr, "stretch-blt-lo-tree-hi-children-full-opaque")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit-lo")
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect, 127)
+dump(bmp, spr, "stretch-blt-lo-tree-hi-children-full-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit-lo")
+rect = bmp.rect
+rect.width /= 2
+rect.height /= 2
+rect.x = rect.width
+rect.y = rect.height
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+rect2 = bmp2.rect
+rect2.width /= 2
+rect2.height /= 2
+rect2.x = rect2.width
+bmp.stretch_blt(rect, bmp2, rect2, 127)
+dump(bmp, spr, "stretch-blt-lo-tree-hi-children-quarter-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect)
+dump(bmp, spr, "stretch-blt-hi-tree-lo-children-full-opaque")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect, 127)
+dump(bmp, spr, "stretch-blt-hi-tree-lo-children-full-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+rect = bmp.rect
+rect.width /= 2
+rect.height /= 2
+rect.x = rect.width
+rect.y = rect.height
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+rect2 = bmp2.rect
+rect2.width /= 2
+rect2.height /= 2
+rect2.x = rect2.width
+bmp.stretch_blt(rect, bmp2, rect2, 127)
+dump(bmp, spr, "stretch-blt-hi-tree-lo-children-quarter-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect)
+dump(bmp, spr, "stretch-blt-hi-tree-hi-children-full-opaque")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.stretch_blt(bmp.rect, bmp2, bmp2.rect, 127)
+dump(bmp, spr, "stretch-blt-hi-tree-hi-children-full-semitransparent")
+
+bmp = Bitmap.new("Graphics/Pictures/tree_alpha_16bit")
+rect = bmp.rect
+rect.width /= 2
+rect.height /= 2
+rect.x = rect.width
+rect.y = rect.height
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+rect2 = bmp2.rect
+rect2.width /= 2
+rect2.height /= 2
+rect2.x = rect2.width
+bmp.stretch_blt(rect, bmp2, rect2, 127)
+dump(bmp, spr, "stretch-blt-hi-tree-hi-children-quarter-semitransparent")
+
+bmp = Bitmap.new(640, 480)
+bmp.fill_rect(100, 200, 450, 300, Color.new(0, 0, 0))
+bmp.fill_rect(50, 100, 220, 150, Color.new(255, 0, 0))
+dump(bmp, spr, "fill-rect")
+
+bmp = Bitmap.new(640, 480)
+bmp.gradient_fill_rect(100, 200, 450, 300, Color.new(0, 0, 0), Color.new(0, 0, 255))
+bmp.gradient_fill_rect(50, 100, 220, 150, Color.new(255, 0, 0), Color.new(255, 255, 0))
+dump(bmp, spr, "gradient-fill-rect-horizontal")
+
+bmp = Bitmap.new(640, 480)
+bmp.gradient_fill_rect(100, 200, 450, 300, Color.new(0, 0, 0), Color.new(0, 0, 255), true)
+bmp.gradient_fill_rect(50, 100, 220, 150, Color.new(255, 0, 0), Color.new(255, 255, 0), true)
+dump(bmp, spr, "gradient-fill-rect-vertical")
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.clear_rect(300, 175, 100, 150)
+dump(bmp, spr, "clear-rect-lo-children")
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.clear_rect(300, 175, 100, 150)
+dump(bmp, spr, "clear-rect-hi-children")
+
+# TODO: linear-blur is arguably passing but maybe should have stronger blur?
+bmp = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.blur
+dump(bmp, spr, "linear-blur")
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.radial_blur(0, 10)
+dump(bmp, spr, "radial-blur-0-lo-children")
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.radial_blur(0, 10)
+dump(bmp, spr, "radial-blur-0-hi-children")
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.radial_blur(3, 10)
+dump(bmp, spr, "radial-blur-3-lo-children")
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.radial_blur(3, 10)
+dump(bmp, spr, "radial-blur-3-hi-children")
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.clear
+dump(bmp, spr, "clear-full")
+
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp = Bitmap.new(bmp2.width, bmp2.height)
+for x in (0...bmp2.width)
+	for y in (0...bmp2.height)
+		bmp.set_pixel(x, y, bmp2.get_pixel(x, y))
+	end
+end
+dump(bmp, spr, "get-set-pixel-dimensions")
+
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.clear
+for x in (0...bmp2.width)
+	for y in (0...bmp2.height)
+		bmp.set_pixel(x, y, bmp2.get_pixel(x, y))
+	end
+end
+dump(bmp, spr, "get-set-pixel-clear")
+
+bmp2 = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.hires.clear
+for x in (0...bmp2.hires.width)
+	for y in (0...bmp2.hires.height)
+		bmp.hires.set_pixel(x, y, bmp2.hires.get_pixel(x, y))
+	end
+end
+dump(bmp, spr, "get-set-pixel-direct")
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha-lo")
+bmp.hue_change(180)
+dump(bmp, spr, "hue-change-lo-children")
+
+bmp = Bitmap.new("Graphics/Pictures/children-alpha")
+bmp.hue_change(180)
+dump(bmp, spr, "hue-change-hi-children")
+
+bmp = Bitmap.new(640, 480)
+fnt = Font.new("Liberation Sans", 100)
+bmp.font = fnt
+bmp.draw_text(100, 200, 450, 300, "We <3 Real-ESRGAN", 1)
+dump(bmp, spr, "draw-text-plain")
+
+bmp = Bitmap.new(640, 480)
+fnt = Font.new("Liberation Sans", 15)
+bmp.font = fnt
+bmp.draw_text(100, 200, 450, 300, "We <3 Real-ESRGAN", 0)
+dump(bmp, spr, "draw-text-left")
+
+bmp = Bitmap.new(640, 480)
+fnt = Font.new("Liberation Sans", 15)
+bmp.font = fnt
+bmp.draw_text(100, 200, 450, 300, "We <3 Real-ESRGAN", 2)
+dump(bmp, spr, "draw-text-right")
+
+bmp = Bitmap.new(640, 480)
+fnt = Font.new("Liberation Sans", 100)
+fnt.bold = true
+bmp.font = fnt
+bmp.draw_text(100, 200, 450, 300, "We <3 Real-ESRGAN", 1)
+dump(bmp, spr, "draw-text-bold")
+
+bmp = Bitmap.new(640, 480)
+fnt = Font.new("Liberation Sans", 100)
+fnt.italic = true
+bmp.font = fnt
+bmp.draw_text(100, 200, 450, 300, "We <3 Real-ESRGAN", 1)
+dump(bmp, spr, "draw-text-italic")
+
+bmp = Bitmap.new(640, 480)
+fnt = Font.new("Liberation Sans", 100)
+fnt.color = Color.new(255, 0, 0)
+fnt.outline = false
+bmp.font = fnt
+bmp.draw_text(100, 200, 450, 300, "We <3 Real-ESRGAN", 1)
+dump(bmp, spr, "draw-text-red-no-outline")
+
+bmp = Bitmap.new(640, 480)
+fnt = Font.new("Liberation Sans", 100)
+fnt.color = Color.new(255, 127, 127)
+fnt.shadow = true
+bmp.font = fnt
+bmp.draw_text(100, 200, 450, 300, "We <3 Real-ESRGAN", 1)
+dump(bmp, spr, "draw-text-pink-shadow")
+
+bmp = Bitmap.new(640, 480)
+fnt = Font.new("Liberation Sans", 100)
+fnt.out_color = Color.new(0, 255, 0)
+bmp.font = fnt
+bmp.draw_text(100, 200, 450, 300, "We <3 Real-ESRGAN", 1)
+dump(bmp, spr, "draw-text-green-outline")
+
+# TODO: Animation tests, if we can find a good way to test them.
+
+# Tests are finished, show exit screen
+
+bmp = Bitmap.new(640, 480)
+bmp.fill_rect(0, 0, 640, 480, Color.new(0, 0, 0))
+
+fnt = Font.new("Liberation Sans", 100)
+
+bmp.font = fnt
+bmp.draw_text(0, 0, 640, 240, "High-Res Test Suite", 1)
+bmp.draw_text(0, 240, 640, 240, "Has Finished", 1)
+spr.bitmap = bmp
+
+Graphics.wait(1 * 60)
+
+exit
diff --git a/tests/hires-bitmap/test-results/.RESULTS WILL GO HERE b/tests/hires-bitmap/test-results/.RESULTS WILL GO HERE
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/hires-sprite/Graphics/Pictures/OST_009-Big.jxl b/tests/hires-sprite/Graphics/Pictures/OST_009-Big.jxl
new file mode 100644
index 00000000..d969d7c8
Binary files /dev/null and b/tests/hires-sprite/Graphics/Pictures/OST_009-Big.jxl differ
diff --git a/tests/hires-sprite/Graphics/Pictures/OST_009-Small.jxl b/tests/hires-sprite/Graphics/Pictures/OST_009-Small.jxl
new file mode 100644
index 00000000..3d55e0ee
Binary files /dev/null and b/tests/hires-sprite/Graphics/Pictures/OST_009-Small.jxl differ
diff --git a/tests/hires-sprite/Graphics/Pictures/OST_009.jxl b/tests/hires-sprite/Graphics/Pictures/OST_009.jxl
new file mode 100644
index 00000000..3d55e0ee
Binary files /dev/null and b/tests/hires-sprite/Graphics/Pictures/OST_009.jxl differ
diff --git a/tests/hires-sprite/Hires/Graphics/Pictures/OST_009.jxl b/tests/hires-sprite/Hires/Graphics/Pictures/OST_009.jxl
new file mode 100644
index 00000000..d969d7c8
Binary files /dev/null and b/tests/hires-sprite/Hires/Graphics/Pictures/OST_009.jxl differ
diff --git a/tests/hires-sprite/hires-sprite-test.rb b/tests/hires-sprite/hires-sprite-test.rb
new file mode 100755
index 00000000..7c99680b
--- /dev/null
+++ b/tests/hires-sprite/hires-sprite-test.rb
@@ -0,0 +1,82 @@
+# Test suite for mkxp-z high-res Bitmap replacement.
+# Sprite tests.
+# Copyright 2023 Splendide Imaginarius.
+# License GPLv2+.
+# Test images are from https://github.com/xinntao/Real-ESRGAN/
+#
+# Run the suite via the "customScript" field in mkxp.json.
+# Use RGSS v3 for best results.
+
+def dump2(bmp, spr, desc)
+	spr.bitmap = bmp
+	Graphics.wait(1)
+	#Graphics.wait(5*60)
+	#Graphics.screenshot("test-results/" + desc + ".png")
+	shot = Graphics.snap_to_bitmap
+	shot.to_file("test-results/" + desc + "-lo.png")
+	if !shot.hires.nil?
+		shot.hires.to_file("test-results/" + desc + "-hi.png")
+	end
+	System::puts("Finished " + desc)
+end
+
+def dump(bmp, spr, desc)
+	spr.viewport = nil
+	dump2(bmp, spr, desc + "-direct")
+    spr.tone.gray = 128
+	dump2(bmp, spr, desc + "-directtonegray")
+	spr.tone.gray = 0
+	$vp.ox = 0
+	spr.viewport = $vp
+	dump2(bmp, spr, desc + "-viewport")
+	$vp.ox = 250
+	dump2(bmp, spr, desc + "-viewportshift")
+	$vp.ox = 0
+	$vp.rect.width = 320
+	dump2(bmp, spr, desc + "-viewportsquash")
+	$vp.rect.width = 640
+	$vp.tone.green = -128
+	dump2(bmp, spr, desc + "-viewporttonegreen")
+	$vp.tone.green = 0
+	$vp.tone.gray = 128
+	dump2(bmp, spr, desc + "-viewporttonegray")
+	$vp.tone.gray = 0
+end
+
+# Setup graphics
+Graphics.resize_screen(448, 640)
+
+$vp = Viewport.new()
+
+spr = Sprite.new()
+
+bmp = Bitmap.new("Graphics/Pictures/OST_009-Small")
+spr.zoom_x = 1.0
+spr.zoom_y = 1.0
+dump(bmp, spr, "Small")
+
+bmp = Bitmap.new("Graphics/Pictures/OST_009-Big")
+spr.zoom_x = 448.0 / 1792.0
+spr.zoom_y = 448.0 / 1792.0
+dump(bmp, spr, "Big")
+
+bmp = Bitmap.new("Graphics/Pictures/OST_009")
+spr.zoom_x = 1.0
+spr.zoom_y = 1.0
+dump(bmp, spr, "Substituted")
+
+bmp = Bitmap.new("Graphics/Pictures/OST_009")
+spr.zoom_x = 1.5
+spr.zoom_y = 1.5
+dump(bmp, spr, "Substituted-Zoomed")
+
+bmp = Bitmap.new("Graphics/Pictures/OST_009")
+spr.zoom_x = 448.0 / 1792.0
+spr.zoom_y = 448.0 / 1792.0
+dump(bmp.hires, spr, "Substituted-Explicit")
+
+# Test for null pointer
+spr_null = Sprite.new()
+spr_null.src_rect = Rect.new(0, 0, 448, 640)
+
+exit
diff --git a/tests/hires-sprite/test-results/.RESULTS WILL GO HERE b/tests/hires-sprite/test-results/.RESULTS WILL GO HERE
new file mode 100644
index 00000000..e69de29b