263 lines
9.1 KiB
GLSL
263 lines
9.1 KiB
GLSL
/* OmniScale is derived from the pattern based design of HQnx, but with the following general differences:
|
|
- The actual output calculating was completely redesigned as resolution independent graphic generator. This allows
|
|
scaling to any factor.
|
|
- HQnx approximations that were good enough for a 2x/3x/4x factor were refined, creating smoother gradients.
|
|
- "Quarters" can be interpolated in more ways than in the HQnx filters
|
|
- If a pattern does not provide enough information to determine the suitable scaling interpolation, up to 16 pixels
|
|
per quarter are sampled (in contrast to the usual 9) in order to determine the best interpolation.
|
|
*/
|
|
|
|
/* We use the same colorspace as the HQ algorithms. */
|
|
STATIC vec3 rgb_to_hq_colospace(vec4 rgb)
|
|
{
|
|
return vec3( 0.250 * rgb.r + 0.250 * rgb.g + 0.250 * rgb.b,
|
|
0.250 * rgb.r - 0.000 * rgb.g - 0.250 * rgb.b,
|
|
-0.125 * rgb.r + 0.250 * rgb.g - 0.125 * rgb.b);
|
|
}
|
|
|
|
|
|
STATIC bool is_different(vec4 a, vec4 b)
|
|
{
|
|
vec3 diff = abs(rgb_to_hq_colospace(a) - rgb_to_hq_colospace(b));
|
|
return diff.x > 0.018 || diff.y > 0.002 || diff.z > 0.005;
|
|
}
|
|
|
|
#define P(m, r) ((pattern & (m)) == (r))
|
|
|
|
STATIC vec4 scale(sampler2D image, vec2 position, vec2 input_resolution, vec2 output_resolution)
|
|
{
|
|
// o = offset, the width of a pixel
|
|
vec2 o = 1.0 / input_resolution;
|
|
|
|
/* We always calculate the top left quarter. If we need a different quarter, we flip our co-ordinates */
|
|
|
|
// p = the position within a pixel [0...1]
|
|
vec2 p = fract(position * input_resolution);
|
|
|
|
if (p.x > 0.5) {
|
|
o.x = -o.x;
|
|
p.x = 1.0 - p.x;
|
|
}
|
|
if (p.y > 0.5) {
|
|
o.y = -o.y;
|
|
p.y = 1.0 - p.y;
|
|
}
|
|
|
|
vec4 w0 = texture(image, position + vec2( -o.x, -o.y));
|
|
vec4 w1 = texture(image, position + vec2( 0, -o.y));
|
|
vec4 w2 = texture(image, position + vec2( o.x, -o.y));
|
|
vec4 w3 = texture(image, position + vec2( -o.x, 0));
|
|
vec4 w4 = texture(image, position + vec2( 0, 0));
|
|
vec4 w5 = texture(image, position + vec2( o.x, 0));
|
|
vec4 w6 = texture(image, position + vec2( -o.x, o.y));
|
|
vec4 w7 = texture(image, position + vec2( 0, o.y));
|
|
vec4 w8 = texture(image, position + vec2( o.x, o.y));
|
|
|
|
int pattern = 0;
|
|
if (is_different(w0, w4)) pattern |= 1 << 0;
|
|
if (is_different(w1, w4)) pattern |= 1 << 1;
|
|
if (is_different(w2, w4)) pattern |= 1 << 2;
|
|
if (is_different(w3, w4)) pattern |= 1 << 3;
|
|
if (is_different(w5, w4)) pattern |= 1 << 4;
|
|
if (is_different(w6, w4)) pattern |= 1 << 5;
|
|
if (is_different(w7, w4)) pattern |= 1 << 6;
|
|
if (is_different(w8, w4)) pattern |= 1 << 7;
|
|
|
|
if ((P(0xbf,0x37) || P(0xdb,0x13)) && is_different(w1, w5)) {
|
|
return mix(w4, w3, 0.5 - p.x);
|
|
}
|
|
if ((P(0xdb,0x49) || P(0xef,0x6d)) && is_different(w7, w3)) {
|
|
return mix(w4, w1, 0.5 - p.y);
|
|
}
|
|
if ((P(0x0b,0x0b) || P(0xfe,0x4a) || P(0xfe,0x1a)) && is_different(w3, w1)) {
|
|
return w4;
|
|
}
|
|
if ((P(0x6f,0x2a) || P(0x5b,0x0a) || P(0xbf,0x3a) || P(0xdf,0x5a) ||
|
|
P(0x9f,0x8a) || P(0xcf,0x8a) || P(0xef,0x4e) || P(0x3f,0x0e) ||
|
|
P(0xfb,0x5a) || P(0xbb,0x8a) || P(0x7f,0x5a) || P(0xaf,0x8a) ||
|
|
P(0xeb,0x8a)) && is_different(w3, w1)) {
|
|
return mix(w4, mix(w4, w0, 0.5 - p.x), 0.5 - p.y);
|
|
}
|
|
if (P(0x0b,0x08)) {
|
|
return mix(mix(w0 * 0.375 + w1 * 0.25 + w4 * 0.375, w4 * 0.5 + w1 * 0.5, p.x * 2.0), w4, p.y * 2.0);
|
|
}
|
|
if (P(0x0b,0x02)) {
|
|
return mix(mix(w0 * 0.375 + w3 * 0.25 + w4 * 0.375, w4 * 0.5 + w3 * 0.5, p.y * 2.0), w4, p.x * 2.0);
|
|
}
|
|
if (P(0x2f,0x2f)) {
|
|
float dist = length(p - vec2(0.5));
|
|
float pixel_size = length(1.0 / (output_resolution / input_resolution));
|
|
if (dist < 0.5 - pixel_size / 2) {
|
|
return w4;
|
|
}
|
|
vec4 r;
|
|
if (is_different(w0, w1) || is_different(w0, w3)) {
|
|
r = mix(w1, w3, p.y - p.x + 0.5);
|
|
}
|
|
else {
|
|
r = mix(mix(w1 * 0.375 + w0 * 0.25 + w3 * 0.375, w3, p.y * 2.0), w1, p.x * 2.0);
|
|
}
|
|
|
|
if (dist > 0.5 + pixel_size / 2) {
|
|
return r;
|
|
}
|
|
return mix(w4, r, (dist - 0.5 + pixel_size / 2) / pixel_size);
|
|
}
|
|
if (P(0xbf,0x37) || P(0xdb,0x13)) {
|
|
float dist = p.x - 2.0 * p.y;
|
|
float pixel_size = length(1.0 / (output_resolution / input_resolution)) * sqrt(5.0);
|
|
if (dist > pixel_size / 2) {
|
|
return w1;
|
|
}
|
|
vec4 r = mix(w3, w4, p.x + 0.5);
|
|
if (dist < -pixel_size / 2) {
|
|
return r;
|
|
}
|
|
return mix(r, w1, (dist + pixel_size / 2) / pixel_size);
|
|
}
|
|
if (P(0xdb,0x49) || P(0xef,0x6d)) {
|
|
float dist = p.y - 2.0 * p.x;
|
|
float pixel_size = length(1.0 / (output_resolution / input_resolution)) * sqrt(5.0);
|
|
if (p.y - 2.0 * p.x > pixel_size / 2) {
|
|
return w3;
|
|
}
|
|
vec4 r = mix(w1, w4, p.x + 0.5);
|
|
if (dist < -pixel_size / 2) {
|
|
return r;
|
|
}
|
|
return mix(r, w3, (dist + pixel_size / 2) / pixel_size);
|
|
}
|
|
if (P(0xbf,0x8f) || P(0x7e,0x0e)) {
|
|
float dist = p.x + 2.0 * p.y;
|
|
float pixel_size = length(1.0 / (output_resolution / input_resolution)) * sqrt(5.0);
|
|
|
|
if (dist > 1.0 + pixel_size / 2) {
|
|
return w4;
|
|
}
|
|
|
|
vec4 r;
|
|
if (is_different(w0, w1) || is_different(w0, w3)) {
|
|
r = mix(w1, w3, p.y - p.x + 0.5);
|
|
}
|
|
else {
|
|
r = mix(mix(w1 * 0.375 + w0 * 0.25 + w3 * 0.375, w3, p.y * 2.0), w1, p.x * 2.0);
|
|
}
|
|
|
|
if (dist < 1.0 - pixel_size / 2) {
|
|
return r;
|
|
}
|
|
|
|
return mix(r, w4, (dist + pixel_size / 2 - 1.0) / pixel_size);
|
|
}
|
|
|
|
if (P(0x7e,0x2a) || P(0xef,0xab)) {
|
|
float dist = p.y + 2.0 * p.x;
|
|
float pixel_size = length(1.0 / (output_resolution / input_resolution)) * sqrt(5.0);
|
|
|
|
if (p.y + 2.0 * p.x > 1.0 + pixel_size / 2) {
|
|
return w4;
|
|
}
|
|
|
|
vec4 r;
|
|
|
|
if (is_different(w0, w1) || is_different(w0, w3)) {
|
|
r = mix(w1, w3, p.y - p.x + 0.5);
|
|
}
|
|
else {
|
|
r = mix(mix(w1 * 0.375 + w0 * 0.25 + w3 * 0.375, w3, p.y * 2.0), w1, p.x * 2.0);
|
|
}
|
|
|
|
if (dist < 1.0 - pixel_size / 2) {
|
|
return r;
|
|
}
|
|
|
|
return mix(r, w4, (dist + pixel_size / 2 - 1.0) / pixel_size);
|
|
}
|
|
|
|
if (P(0x1b,0x03) || P(0x4f,0x43) || P(0x8b,0x83) || P(0x6b,0x43)) {
|
|
return mix(w4, w3, 0.5 - p.x);
|
|
}
|
|
|
|
if (P(0x4b,0x09) || P(0x8b,0x89) || P(0x1f,0x19) || P(0x3b,0x19)) {
|
|
return mix(w4, w1, 0.5 - p.y);
|
|
}
|
|
|
|
if (P(0xfb,0x6a) || P(0x6f,0x6e) || P(0x3f,0x3e) || P(0xfb,0xfa) ||
|
|
P(0xdf,0xde) || P(0xdf,0x1e)) {
|
|
return mix(w4, w0, (1.0 - p.x - p.y) / 2.0);
|
|
}
|
|
|
|
if (P(0x4f,0x4b) || P(0x9f,0x1b) || P(0x2f,0x0b) ||
|
|
P(0xbe,0x0a) || P(0xee,0x0a) || P(0x7e,0x0a) || P(0xeb,0x4b) ||
|
|
P(0x3b,0x1b)) {
|
|
float dist = p.x + p.y;
|
|
float pixel_size = length(1.0 / (output_resolution / input_resolution));
|
|
|
|
if (dist > 0.5 + pixel_size / 2) {
|
|
return w4;
|
|
}
|
|
|
|
vec4 r;
|
|
if (is_different(w0, w1) || is_different(w0, w3)) {
|
|
r = mix(w1, w3, p.y - p.x + 0.5);
|
|
}
|
|
else {
|
|
r = mix(mix(w1 * 0.375 + w0 * 0.25 + w3 * 0.375, w3, p.y * 2.0), w1, p.x * 2.0);
|
|
}
|
|
|
|
if (dist < 0.5 - pixel_size / 2) {
|
|
return r;
|
|
}
|
|
|
|
return mix(r, w4, (dist + pixel_size / 2 - 0.5) / pixel_size);
|
|
}
|
|
|
|
if (P(0x0b,0x01)) {
|
|
return mix(mix(w4, w3, 0.5 - p.x), mix(w1, (w1 + w3) / 2.0, 0.5 - p.x), 0.5 - p.y);
|
|
}
|
|
|
|
if (P(0x0b,0x00)) {
|
|
return mix(mix(w4, w3, 0.5 - p.x), mix(w1, w0, 0.5 - p.x), 0.5 - p.y);
|
|
}
|
|
|
|
float dist = p.x + p.y;
|
|
float pixel_size = length(1.0 / (output_resolution / input_resolution));
|
|
|
|
if (dist > 0.5 + pixel_size / 2) {
|
|
return w4;
|
|
}
|
|
|
|
/* We need more samples to "solve" this diagonal */
|
|
vec4 x0 = texture(image, position + vec2( -o.x * 2.0, -o.y * 2.0));
|
|
vec4 x1 = texture(image, position + vec2( -o.x , -o.y * 2.0));
|
|
vec4 x2 = texture(image, position + vec2( 0.0 , -o.y * 2.0));
|
|
vec4 x3 = texture(image, position + vec2( o.x , -o.y * 2.0));
|
|
vec4 x4 = texture(image, position + vec2( -o.x * 2.0, -o.y ));
|
|
vec4 x5 = texture(image, position + vec2( -o.x * 2.0, 0.0 ));
|
|
vec4 x6 = texture(image, position + vec2( -o.x * 2.0, o.y ));
|
|
|
|
if (is_different(x0, w4)) pattern |= 1 << 8;
|
|
if (is_different(x1, w4)) pattern |= 1 << 9;
|
|
if (is_different(x2, w4)) pattern |= 1 << 10;
|
|
if (is_different(x3, w4)) pattern |= 1 << 11;
|
|
if (is_different(x4, w4)) pattern |= 1 << 12;
|
|
if (is_different(x5, w4)) pattern |= 1 << 13;
|
|
if (is_different(x6, w4)) pattern |= 1 << 14;
|
|
|
|
int diagonal_bias = -7;
|
|
while (pattern != 0) {
|
|
diagonal_bias += pattern & 1;
|
|
pattern >>= 1;
|
|
}
|
|
|
|
if (diagonal_bias <= 0) {
|
|
vec4 r = mix(w1, w3, p.y - p.x + 0.5);
|
|
if (dist < 0.5 - pixel_size / 2) {
|
|
return r;
|
|
}
|
|
return mix(r, w4, (dist + pixel_size / 2 - 0.5) / pixel_size);
|
|
}
|
|
|
|
return w4;
|
|
}
|