Pixel-Composer/shaders/sh_displace/sh_displace.fsh
2023-02-28 15:43:01 +07:00

74 lines
1.6 KiB
GLSL

//
// Simple passthrough fragment shader
//
varying vec2 v_vTexcoord;
varying vec4 v_vColour;
uniform sampler2D map;
uniform vec2 dimension;
uniform vec2 map_dimension;
uniform vec2 displace;
uniform float strength;
uniform float middle;
uniform int iterate;
uniform int use_rg;
uniform int sampleMode;
#define PI 3.14159265359
float bright(in vec4 col) {
return dot(col.rgb, vec3(0.2126, 0.7152, 0.0722)) * col.a;
}
vec4 sampleTexture(vec2 pos) {
if(pos.x >= 0. && pos.y >= 0. && pos.x <= 1. && pos.y <= 1.)
return texture2D(gm_BaseTexture, pos);
if(sampleMode == 0)
return vec4(0.);
if(sampleMode == 1)
return texture2D(gm_BaseTexture, clamp(pos, 0., 1.));
if(sampleMode == 2)
return texture2D(gm_BaseTexture, fract(pos));
return vec4(0.);
}
vec2 shiftMap(in vec2 pos, in float str) {
vec4 disP = texture2D( map, pos );
vec2 sam_pos;
vec2 raw_displace = displace / dimension;
float _str;
if(use_rg == 1) {
vec2 _disp = vec2(disP.r - middle, disP.g - middle) * vec2((disP.r + disP.g + disP.b) / 3. - middle) * str;
sam_pos = pos + _disp;
} else if(use_rg == 2) {
float _ang = disP.r * PI * 2.;
_str = (disP.g - middle) * str;
sam_pos = pos + _str * vec2(cos(_ang), sin(_ang));
} else {
_str = (bright(disP) - middle) * str;
sam_pos = pos + _str * raw_displace;
}
return sam_pos;
}
void main() {
vec2 samPos = v_vTexcoord;
if(iterate == 1) {
for(float i = 0.; i < strength; i++)
samPos = shiftMap(samPos, 1.);
} else
samPos = shiftMap(samPos, strength);
vec4 col = sampleTexture( samPos );
gl_FragColor = col;
}