SameBoy/Shaders/AAOmniScaleLegacy.fsh

119 lines
3.7 KiB
Plaintext
Raw Normal View History

STATIC float quickDistance(vec4 a, vec4 b)
{
return abs(a.x - b.x) + abs(a.y - b.y) + abs(a.z - b.z);
}
STATIC vec4 omniScale(sampler2D image, vec2 position, vec2 input_resolution, vec2 output_resolution)
{
2018-06-15 15:08:54 +00:00
vec2 pixel = position * input_resolution - vec2(0.5, 0.5);
2018-06-15 15:08:54 +00:00
vec4 q11 = texture(image, (floor(pixel) + 0.5) / input_resolution);
vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / input_resolution);
vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / input_resolution);
vec4 q22 = texture(image, (ceil(pixel) + 0.5) / input_resolution);
vec2 pos = fract(pixel);
/* Special handling for diaonals */
bool hasDownDiagonal = false;
bool hasUpDiagonal = false;
2018-06-15 16:11:06 +00:00
if (equal(q12, q21) && inequal(q11, q22)) hasUpDiagonal = true;
else if (inequal(q12, q21) && equal(q11, q22)) hasDownDiagonal = true;
else if (equal(q12, q21) && equal(q11, q22)) {
if (equal(q11, q12)) return q11;
int diagonalBias = 0;
for (float y = -1.0; y < 3.0; y++) {
for (float x = -1.0; x < 3.0; x++) {
2018-06-15 15:08:54 +00:00
vec4 color = texture(image, (pixel + vec2(x, y)) / input_resolution);
2018-06-15 16:11:06 +00:00
if (equal(color, q11)) diagonalBias++;
if (equal(color, q12)) diagonalBias--;
}
}
if (diagonalBias <= 0) {
hasDownDiagonal = true;
}
if (diagonalBias >= 0) {
hasUpDiagonal = true;
}
}
if (hasUpDiagonal || hasDownDiagonal) {
vec4 downDiagonalResult, upDiagonalResult;
if (hasUpDiagonal) {
float diagonalPos = pos.x + pos.y;
if (diagonalPos < 0.5) {
upDiagonalResult = q11;
}
else if (diagonalPos > 1.5) {
upDiagonalResult = q22;
}
else {
upDiagonalResult = q12;
}
}
if (hasDownDiagonal) {
float diagonalPos = 1.0 - pos.x + pos.y;
if (diagonalPos < 0.5) {
downDiagonalResult = q21;
}
else if (diagonalPos > 1.5) {
downDiagonalResult = q12;
}
else {
downDiagonalResult = q11;
}
}
if (!hasUpDiagonal) return downDiagonalResult;
if (!hasDownDiagonal) return upDiagonalResult;
return mix(downDiagonalResult, upDiagonalResult, 0.5);
}
vec4 r1 = mix(q11, q21, fract(pos.x));
vec4 r2 = mix(q12, q22, fract(pos.x));
vec4 unqunatized = mix(r1, r2, fract(pos.y));
float q11d = quickDistance(unqunatized, q11);
float q21d = quickDistance(unqunatized, q21);
float q12d = quickDistance(unqunatized, q12);
float q22d = quickDistance(unqunatized, q22);
float best = min(q11d,
min(q21d,
min(q12d,
q22d)));
2018-06-15 16:11:06 +00:00
if (equal(q11d, best)) {
return q11;
}
2018-06-15 16:11:06 +00:00
if (equal(q21d, best)) {
return q21;
}
2018-06-15 16:11:06 +00:00
if (equal(q12d, best)) {
return q12;
}
return q22;
}
STATIC vec4 scale(sampler2D image, vec2 position, vec2 input_resolution, vec2 output_resolution)
{
2018-06-15 15:08:54 +00:00
vec2 pixel = vec2(1.0, 1.0) / output_resolution;
// 4-pixel super sampling
2018-06-15 15:22:09 +00:00
vec4 q11 = omniScale(image, position + pixel * vec2(-0.25, -0.25), input_resolution, output_resolution);
vec4 q21 = omniScale(image, position + pixel * vec2(+0.25, -0.25), input_resolution, output_resolution);
vec4 q12 = omniScale(image, position + pixel * vec2(-0.25, +0.25), input_resolution, output_resolution);
vec4 q22 = omniScale(image, position + pixel * vec2(+0.25, +0.25), input_resolution, output_resolution);
return (q11 + q21 + q12 + q22) / 4.0;
2018-06-15 15:08:54 +00:00
}