50 lines
1.8 KiB
GLSL
50 lines
1.8 KiB
GLSL
uniform sampler2D u_Tex0;
|
|
varying vec2 v_TexCoord;
|
|
|
|
// some const, tweak for best look
|
|
const float sampleDist = 1.0;
|
|
const float sampleStrength = 2.2;
|
|
|
|
void main(void)
|
|
{
|
|
// 0.5,0.5 is the center of the screen
|
|
// so substracting v_TexCoord from it will result in
|
|
// a vector pointing to the middle of the screen
|
|
vec2 dir = 0.5 - v_TexCoord;
|
|
|
|
// calculate the distance to the center of the screen
|
|
float dist = sqrt(dir.x*dir.x + dir.y*dir.y);
|
|
|
|
// normalize the direction (reuse the distance)
|
|
dir = dir/dist;
|
|
|
|
// this is the original colour of this fragment
|
|
// using only this would result in a nonblurred version
|
|
vec4 color = texture2D(u_Tex0,v_TexCoord);
|
|
|
|
vec4 sum = color;
|
|
|
|
// take 10 additional blur samples in the direction towards
|
|
// the center of the screen
|
|
sum += texture2D(u_Tex0, v_TexCoord - 0.08 * dir * sampleDist);
|
|
sum += texture2D(u_Tex0, v_TexCoord - 0.05 * dir * sampleDist);
|
|
sum += texture2D(u_Tex0, v_TexCoord - 0.03 * dir * sampleDist);
|
|
sum += texture2D(u_Tex0, v_TexCoord - 0.02 * dir * sampleDist);
|
|
sum += texture2D(u_Tex0, v_TexCoord - 0.01 * dir * sampleDist);
|
|
sum += texture2D(u_Tex0, v_TexCoord + 0.01 * dir * sampleDist);
|
|
sum += texture2D(u_Tex0, v_TexCoord + 0.02 * dir * sampleDist);
|
|
sum += texture2D(u_Tex0, v_TexCoord + 0.03 * dir * sampleDist);
|
|
sum += texture2D(u_Tex0, v_TexCoord + 0.05 * dir * sampleDist);
|
|
sum += texture2D(u_Tex0, v_TexCoord + 0.08 * dir * sampleDist);
|
|
|
|
// we have taken eleven samples
|
|
sum *= 1.0/11.0;
|
|
|
|
// weighten the blur effect with the distance to the
|
|
// center of the screen ( further out is blurred more)
|
|
float t = dist * sampleStrength;
|
|
t = clamp(t ,0.0,1.0); //0 <= t <= 1
|
|
|
|
//Blend the original color with the averaged pixels
|
|
gl_FragColor = mix(color, sum, t);
|
|
} |