HaxeFlixel/flixel

package flixel.graphics.tile;

import openfl.display.GraphicsShader;

class FlxGraphicsShader extends GraphicsShader
{
    @:glVertexSource("
        #pragma header
        
        attribute float alpha;
        attribute vec4 colorMultiplier;
        attribute vec4 colorOffset;
        uniform bool hasColorTransform;
        
        void main(void)
        {
            #pragma body
            
            openfl_Alphav = openfl_Alpha * alpha;
            
            if (hasColorTransform)
            {
                openfl_ColorOffsetv = colorOffset / 255.0;
                openfl_ColorMultiplierv = colorMultiplier;
            }
        }")
    @:glFragmentHeader("
        uniform bool hasTransform;
        uniform bool hasColorTransform;

        vec4 flixel_texture2D(sampler2D bitmap, vec2 coord)
        {
            vec4 color = texture2D(bitmap, coord);
            if (!hasTransform)
            {
                return color;
            }

            if (color.a == 0.0)
            {
                return vec4(0.0, 0.0, 0.0, 0.0);
            }

            if (!hasColorTransform)
            {
                return color * openfl_Alphav;
            }

            color = vec4(color.rgb / color.a, color.a);

            mat4 colorMultiplier = mat4(0);
            colorMultiplier[0][0] = openfl_ColorMultiplierv.x;
            colorMultiplier[1][1] = openfl_ColorMultiplierv.y;
            colorMultiplier[2][2] = openfl_ColorMultiplierv.z;
            colorMultiplier[3][3] = openfl_ColorMultiplierv.w;

            color = clamp(openfl_ColorOffsetv + (color * colorMultiplier), 0.0, 1.0);

            if (color.a > 0.0)
            {
                return vec4(color.rgb * color.a * openfl_Alphav, color.a * openfl_Alphav);
            }
            return vec4(0.0, 0.0, 0.0, 0.0);
        }
    ")
    @:glFragmentSource("
        #pragma header
        
        void main(void)
        {
            gl_FragColor = flixel_texture2D(bitmap, openfl_TextureCoordv);
        }")
    public function new()
    {
        super();
    }
}