mirror of
https://github.com/bsnes-emu/bsnes.git
synced 2025-02-23 14:42:33 +01:00
0c80ac3296
Sampling at the edge between texels causes one or the other to be chosen semi-randomly, depending on rounding errors. Add half a pixel so they sample at texel centers instead.
18 lines
691 B
GLSL
18 lines
691 B
GLSL
vec4 scale(sampler2D image)
|
|
{
|
|
vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
|
|
|
|
vec2 pixel = texCoord * textureDimensions - vec2(0.5, 0.5);
|
|
|
|
vec4 q11 = texture(image, (floor(pixel) + 0.5) / textureDimensions);
|
|
vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / textureDimensions);
|
|
vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / textureDimensions);
|
|
vec4 q22 = texture(image, (ceil(pixel) + 0.5) / textureDimensions);
|
|
|
|
vec2 s = smoothstep(0., 1., fract(pixel));
|
|
|
|
vec4 r1 = mix(q11, q21, fract(s.x));
|
|
vec4 r2 = mix(q12, q22, fract(s.x));
|
|
|
|
return mix (r1, r2, fract(s.y));
|
|
} |