Files
doom-dm/PresenterConsole/assets/shader/ascii.shader
2024-12-16 08:27:20 +03:00

136 lines
3.8 KiB
GLSL

// #type vertex
#version 460 core
layout (location = 0) in vec2 aPos;
layout (location = 1) in vec2 aUV;
layout (location = 0) out vec2 oUV;
void main()
{
oUV = aUV;
gl_Position = vec4(aPos, 0.0, 1.0);
}
// #type fragment
#version 460 core
precision highp float;
// ConsoleColor vec3 palette (normalized)
const vec3 ConsoleColorVec3[16] = vec3[](
vec3(0.0, 0.0, 0.0), // Black
vec3(0.0, 0.0, 0.5), // DarkBlue
vec3(0.0, 0.5, 0.0), // DarkGreen
vec3(0.0, 0.5, 0.5), // DarkCyan
vec3(0.5, 0.0, 0.0), // DarkRed
vec3(0.5, 0.0, 0.5), // DarkMagenta
vec3(0.5, 0.5, 0.0), // DarkYellow
vec3(0.5, 0.5, 0.5), // Gray
vec3(0.25, 0.25, 0.25), // DarkGray
vec3(0.0, 0.0, 1.0), // Blue
vec3(0.0, 1.0, 0.0), // Green
vec3(0.0, 1.0, 1.0), // Cyan
vec3(1.0, 0.0, 0.0), // Red
vec3(1.0, 0.0, 1.0), // Magenta
vec3(1.0, 1.0, 0.0), // Yellow
vec3(1.0, 1.0, 1.0) // White
);
vec3 srgbToLinear(vec3 color) {
return mix(color / 12.92, pow((color + 0.055) / 1.055, vec3(2.4)), step(0.04045, color));
}
vec3 rgbToXyz(vec3 color) {
const mat3 rgbToXyzMatrix = mat3(
0.4124564, 0.3575761, 0.1804375,
0.2126729, 0.7151522, 0.0721750,
0.0193339, 0.1191920, 0.9503041
);
return rgbToXyzMatrix * color;
}
vec3 xyzToLab(vec3 xyz) {
const vec3 whitePoint = vec3(0.95047, 1.0, 1.08883); // D65 white point
xyz = xyz / whitePoint;
vec3 f = mix(pow(xyz, vec3(1.0 / 3.0)), 7.787 * xyz + 16.0 / 116.0, step(0.008856, xyz));
return vec3(
(116.0 * f.y) - 16.0,
500.0 * (f.x - f.y),
200.0 * (f.y - f.z)
);
}
vec3 rgb2hsv(vec3 c)
{
vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
float d = q.x - min(q.w, q.y);
float e = 1.0e-10;
return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
}
float perceptualColorDistance(vec3 color1, vec3 color2) {
vec3 lab1 = xyzToLab(rgbToXyz(srgbToLinear(color1)));
vec3 lab2 = xyzToLab(rgbToXyz(srgbToLinear(color2)));
vec3 delta = lab1 - lab2;
return dot(delta, delta);
}
int findMostPerceptuallyAccurateColor(vec3 color) {
int bestMatchIndex = 0;
float minDistance = perceptualColorDistance(color, ConsoleColorVec3[0]);
for (int i = 1; i < 16; i++) {
float currentDistance = perceptualColorDistance(color, ConsoleColorVec3[i]);
if (currentDistance < minDistance) {
minDistance = currentDistance;
bestMatchIndex = i;
}
}
return bestMatchIndex;
}
// Enhanced luminosity calculation considering human perception
float calculatePerceptualLuminance(vec3 color) {
// BT.709 luminance coefficients with slight adjustment
return pow(
0.2126 * pow(color.r, 2.2) +
0.7152 * pow(color.g, 2.2) +
0.0722 * pow(color.b, 2.2),
1.0 / 2.2
);
}
// Dithering function to reduce color banding
float interleavedGradientNoise(vec2 pixel) {
return fract(52.982919 * fract(0.06711056 * pixel.x + 0.00583715 * pixel.y));
}
uniform sampler2D uInputTexture;
layout (location = 0) in vec2 iUV;
layout (location = 0) out vec4 FragColor;
void main() {
vec3 pixelColor = texture(uInputTexture, iUV).rgb;
// Find most perceptually accurate console color
int colorIndex = findMostPerceptuallyAccurateColor(pixelColor);
// Calculate perceptual luminance with gamma correction
float luminance = calculatePerceptualLuminance(pixelColor);
// Output with high precision color mapping
FragColor = vec4(
luminance, // Red: Perceptual luminance
float(colorIndex) / 15.0, // Green: Normalized color index
0.0, // Blue: Unused
1.0 // Alpha
);
}