bump.glsl

gistfile1.glsl

uniform sampler2D tex;
uniform sampler2D lightFromLeft;
uniform sampler2D lightFromTop;
uniform sampler2D lightFromRight;
uniform sampler2D lightFromBottom;
uniform sampler2D bump;
uniform vec4 tint;
uniform float strength;
uniform vec2 lightSize;
uniform float screenHeight;
uniform int flipped;
uniform float angle;

void main(void) {
    vec4 bumpLookup = texture2D(bump, floor(gl_TexCoord[0].st) / 1024.0);
    
    float topM = max(bumpLookup.x - 0.3, 0.0) * 2.0 * bumpLookup.z * strength;
    float bottomM = max(0.7 - bumpLookup.x, 0.0) * 2.0 * bumpLookup.z * strength;
    float leftM = max(bumpLookup.y - 0.3, 0.0) * 2.0 * bumpLookup.z * strength;
    float rightM = max(0.7 - bumpLookup.y, 0.0) * 2.0 * bumpLookup.z * strength;
    
    float m0 = max(0, cos(angle));
    float m1 = max(0, cos(angle + 0.785398163));
    float m2 = max(0, cos(angle + 1.570796327));
    float m3 = max(0, cos(angle + 2.35619449));
    
    vec4 lightTop = texture2D(lightFromTop, vec2(gl_FragCoord.x, screenHeight - gl_FragCoord.y) / lightSize / 8.0);
    vec4 lightBottom = texture2D(lightFromBottom, vec2(gl_FragCoord.x, screenHeight - gl_FragCoord.y) / lightSize / 8.0);
    vec4 lightLeft = texture2D(lightFromLeft, vec2(gl_FragCoord.x, screenHeight - gl_FragCoord.y) / lightSize / 8.0);
    vec4 lightRight = texture2D(lightFromRight, vec2(gl_FragCoord.x, screenHeight - gl_FragCoord.y) / lightSize / 8.0);
    
    if (flipped == 1) {
        vec4 totalLight =
            topM * (lightTop * m0 + lightRight * m1 + lightBottom * m2 + lightLeft * m3) + // top
            leftM * (lightTop * m3 + lightRight * m0 + lightBottom * m1 + lightLeft * m2) + // left
            bottomM * (lightTop * m2 + lightRight * m3 + lightBottom * m0 + lightLeft * m1) + // bottom
            rightM * (lightTop * m1 + lightRight * m2 + lightBottom * m3 + lightLeft * m0); // right
    
        gl_FragColor = texture2D(tex, floor(gl_TexCoord[0].st) / 1024.0) * tint + vec4(totalLight.x, totalLight.y, totalLight.z, 0);
    } else {
        vec4 totalLight =
            topM * (lightTop * m0 + lightRight * m1 + lightBottom * m2 + lightLeft * m3) + // top
            rightM * (lightTop * m3 + lightRight * m0 + lightBottom * m1 + lightLeft * m2) + // left
            bottomM * (lightTop * m2 + lightRight * m3 + lightBottom * m0 + lightLeft * m1) + // bottom
            leftM * (lightTop * m1 + lightRight * m2 + lightBottom * m3 + lightLeft * m0); // right
    
        gl_FragColor = texture2D(tex, floor(gl_TexCoord[0].st) / 1024.0) * tint + vec4(totalLight.x, totalLight.y, totalLight.z, 0);
    }
}