mkxp-z/shader/sprite.frag

uniform sampler2D v_texture;

uniform lowp vec4 tone;

uniform lowp float opacity;
uniform lowp vec4 color;

uniform float bushDepth;
uniform lowp float bushOpacity;

in vec2 v_texCoord;

const vec3 lumaF = vec3(.299, .587, .114);

out vec4 fragColor;

void main() {
  /* Sample source color */
  vec4 frag = texture(v_texture, v_texCoord);

  /* Apply gray */
  float luma = dot(frag.rgb, lumaF);
  frag.rgb = mix(frag.rgb, vec3(luma), tone.w);

  /* Apply tone */
  frag.rgb += tone.rgb;

  /* Apply opacity */
  frag.a *= opacity;

  /* Apply color */
  frag.rgb = mix(frag.rgb, color.rgb, color.a);

  /* Apply bush alpha by mathematical if */
  lowp float underBush = float(v_texCoord.y < bushDepth);
  frag.a *= clamp(bushOpacity + underBush, 0.0, 1.0);

  fragColor = frag;
}