rhythmbullet/android/assets/shaders/gaussian_blur.fsh
2018-09-03 19:31:16 -05:00

47 lines
1.7 KiB
GLSL
Executable File

varying vec4 vColor;
varying vec2 vTexCoord;
uniform sampler2D u_texture;
uniform vec2 resolution;
uniform float radius;
uniform int pass;
void main() {
//this will be our RGBA sum
vec4 sum = vec4(0.0);
//our original texcoord for this fragment
vec2 tc = vTexCoord;
//the amount to blur, i.e. how far off center to sample from
//1.0 -> blur by one pixel
//2.0 -> blur by two pixels, etc.
float blur = radius/resolution.y;
//the direction of our blur
//(1.0, 0.0) -> x-axis blur
//(0.0, 1.0) -> y-axis blur
float hstep = 1.0;
float vstep = 0.0;
if (pass == 1) {
hstep = 0.0;
vstep = 1.0;
}
sum += texture2D(u_texture, vec2(tc.x - 5.0*blur*hstep, tc.y - 5.0*blur*vstep)) * 0.014374;
sum += texture2D(u_texture, vec2(tc.x - 4.0*blur*hstep, tc.y - 4.0*blur*vstep)) * 0.035855;
sum += texture2D(u_texture, vec2(tc.x - 3.0*blur*hstep, tc.y - 3.0*blur*vstep)) * 0.072994;
sum += texture2D(u_texture, vec2(tc.x - 2.0*blur*hstep, tc.y - 2.0*blur*vstep)) * 0.121281;
sum += texture2D(u_texture, vec2(tc.x - 1.0*blur*hstep, tc.y - 1.0*blur*vstep)) * 0.164472;
sum += texture2D(u_texture, vec2(tc.x, tc.y)) * 0.182049;
sum += texture2D(u_texture, vec2(tc.x + 1.0*blur*hstep, tc.y + 1.0*blur*vstep)) * 0.164472;
sum += texture2D(u_texture, vec2(tc.x + 2.0*blur*hstep, tc.y + 2.0*blur*vstep)) * 0.121281;
sum += texture2D(u_texture, vec2(tc.x + 3.0*blur*hstep, tc.y + 3.0*blur*vstep)) * 0.072994;
sum += texture2D(u_texture, vec2(tc.x + 4.0*blur*hstep, tc.y + 4.0*blur*vstep)) * 0.035855;
sum += texture2D(u_texture, vec2(tc.x + 5.0*blur*hstep, tc.y + 5.0*blur*vstep)) * 0.014374;
gl_FragColor = vColor * vec4(sum.rgb, 1.0);
}