mirror of
https://github.com/libretro/bsnes-libretro.git
synced 2024-11-23 08:59:40 +00:00
45 lines
1.6 KiB
GLSL
45 lines
1.6 KiB
GLSL
STATIC vec4 scale2x(sampler2D image, vec2 position, vec2 input_resolution, vec2 output_resolution)
|
|
{
|
|
// o = offset, the width of a pixel
|
|
vec2 o = 1.0 / input_resolution;
|
|
|
|
// texel arrangement
|
|
// A B C
|
|
// D E F
|
|
// G H I
|
|
// vec4 A = texture(image, position + vec2( -o.x, o.y));
|
|
vec4 B = texture(image, position + vec2( 0, o.y));
|
|
// vec4 C = texture(image, position + vec2( o.x, o.y));
|
|
vec4 D = texture(image, position + vec2( -o.x, 0));
|
|
vec4 E = texture(image, position + vec2( 0, 0));
|
|
vec4 F = texture(image, position + vec2( o.x, 0));
|
|
// vec4 G = texture(image, position + vec2( -o.x, -o.y));
|
|
vec4 H = texture(image, position + vec2( 0, -o.y));
|
|
// vec4 I = texture(image, position + vec2( o.x, -o.y));
|
|
vec2 p = position * input_resolution;
|
|
// p = the position within a pixel [0...1]
|
|
p = fract(p);
|
|
if (p.x > .5) {
|
|
if (p.y > .5) {
|
|
// Top Right
|
|
return equal(B, F) && inequal(B, D) && inequal(F, H) ? F : E;
|
|
} else {
|
|
// Bottom Right
|
|
return equal(H, F) && inequal(D, H) && inequal(B, F) ? F : E;
|
|
}
|
|
} else {
|
|
if (p.y > .5) {
|
|
// Top Left
|
|
return equal(D, B) && inequal(B, F) && inequal(D, H) ? D : E;
|
|
} else {
|
|
// Bottom Left
|
|
return equal(D, H) && inequal(D, B) && inequal(H, F) ? D : E;
|
|
}
|
|
}
|
|
}
|
|
|
|
STATIC vec4 scale(sampler2D image, vec2 position, vec2 input_resolution, vec2 output_resolution)
|
|
{
|
|
return mix(texture(image, position), scale2x(image, position, input_resolution, output_resolution), 0.5);
|
|
}
|