Pixel-Composer/shaders/sh_normal/sh_normal.fsh
2023-03-21 09:01:53 +07:00

50 lines
1.7 KiB
GLSL

//
// Simple passthrough fragment shader
//
varying vec2 v_vTexcoord;
varying vec4 v_vColour;
uniform vec2 dimension;
uniform float height;
uniform int smooth;
float bright(in vec4 col) { return dot(col.rgb, vec3(0.2126, 0.7152, 0.0722)) * col.a; }
void main() {
vec2 pixelStep = 1. / dimension;
vec4 c = texture2D(gm_BaseTexture, v_vTexcoord);
float col = bright(c);
float h0 = bright(texture2D(gm_BaseTexture, v_vTexcoord + pixelStep * vec2(-1., 0.)));
float h1 = bright(texture2D(gm_BaseTexture, v_vTexcoord + pixelStep * vec2( 1., 0.)));
float v0 = bright(texture2D(gm_BaseTexture, v_vTexcoord + pixelStep * vec2( 0., -1.)));
float v1 = bright(texture2D(gm_BaseTexture, v_vTexcoord + pixelStep * vec2( 0., 1.)));
float d0 = bright(texture2D(gm_BaseTexture, v_vTexcoord + pixelStep * vec2( 1., -1.)));
float d1 = bright(texture2D(gm_BaseTexture, v_vTexcoord + pixelStep * vec2(-1., -1.)));
float d2 = bright(texture2D(gm_BaseTexture, v_vTexcoord + pixelStep * vec2(-1., 1.)));
float d3 = bright(texture2D(gm_BaseTexture, v_vTexcoord + pixelStep * vec2( 1., 1.)));
vec2 normal;
if(smooth == 1) {
normal = (vec2(h1 - col, 0.)
+ vec2(col - h0, 0.)
+ vec2(0., v1 - col)
+ vec2(0., col - v0)
+ vec2(d0 - col, col - d0) / sqrt(2.)
+ vec2(col - d1, col - d1) / sqrt(2.)
+ vec2(col - d2, d2 - col) / sqrt(2.)
+ vec2(d3 - col, d3 - col) / sqrt(2.)
) / (2. + 2. * sqrt(2.)) * height + 0.5;
} else if(smooth == 0) {
normal = (vec2(h1 - col, 0.)
+ vec2(col - h0, 0.)
+ vec2(0., v1 - col)
+ vec2(0., col - v0)
) / 2. * height + 0.5;
}
gl_FragColor = vec4(normal, 1., c.a);
}