Files
PuzGame/src/game/shaders/dither/frag.sc
2025-05-29 17:33:14 +02:00

112 lines
3.4 KiB
Scala

$input v_color0
$input v_normal
$input v_uv0
$input v_wpos
#include "../common.sh"
SAMPLER2D(s_texColor, 0);
SAMPLER3D(s_ditherSampler, 1);
SAMPLER2D(s_rampSampler, 2);
uniform vec4 u_time;
uniform vec4 u_dotColor;
uniform vec4 u_texInfo;
uniform vec4 u_baseColor;
float calcBrightness(vec3 lightPos, vec3 vertPos, vec3 normal)
{
vec3 lightDir = normalize(lightPos - vertPos);
float diffuse = max(0.0, dot(lightDir, normal));
return diffuse * clamp(1.0 - distance(lightPos, vertPos) * 0.01, 0.0, 1.0);
}
float calcBrightnessDirectional(vec3 sunDir, vec3 normal)
{
return max(0.0, dot(sunDir, normal));
}
vec3 desaturate(vec3 color)
{
return vec3_splat(dot(color, vec3(0.33, 0.34, 0.33)));
}
float dither(float brightness, vec2 inputUv)
{
float globalScale = 8;
// constants
float xRes = u_texInfo.z;
float dotsPerSide = xRes / 16;
float dotsTotal = dotsPerSide * dotsPerSide;
float invXRes = 1 / xRes;
float zRes = dotsTotal;
float invZRes = 1 / zRes;
vec2 rampLookupUv = vec2((0.5 * invXRes + (1 - invXRes) * brightness), 0.5);
float brightnessCurve = texture2D(s_rampSampler, rampLookupUv).r;
// Magic dot frequency calculation
vec2 dx = dFdx(inputUv);
vec2 dy = dFdy(inputUv);
mat2 mat = mat2(dx, dy);
vec4 vectorized = vec4(dx, dy);
float qq = dot(vectorized, vectorized);
float rr = determinant(mat);
float discriminantSqr = max(0.0, qq*qq - 4.0*rr*rr);
float discriminant = sqrt(discriminantSqr);
vec2 freq = sqrt(vec2(qq + discriminant, qq - discriminant) / 2.0);
// Figuring out how many dots we want
float scaleExp = exp2(globalScale);
float spacing = freq.y * scaleExp;
spacing *= dotsPerSide * 0.125;
float brightnessSpacingMultiplier = pow(brightnessCurve * 2 + 0.001, -(1 - 0.5));
// float brightnessSpacingMultiplier = 1;
spacing *= brightnessSpacingMultiplier;
float spacingLog = log2(spacing);
int patternScaleLevel = int(floor(spacingLog));
float patternFractional = spacingLog - patternScaleLevel;
vec2 uv = inputUv / exp2(patternScaleLevel);
// patternFractional *= patternFractional;
// patternFractional = smoothstep(0, 1, patternFractional);
float subLayer = lerp(0.25 * dotsTotal, dotsTotal, 1 - patternFractional);
subLayer = (subLayer - 0.5) * invZRes;
float pattern = texture3D(s_ditherSampler, vec3(uv, subLayer)).r;
float contrast = 2 * scaleExp * brightnessSpacingMultiplier * 0.1;
contrast *= pow(freq.y / freq.x, 1.0);
float baseVal = lerp(0.5, brightness, saturate(1.05 / (1 + contrast)));
float threshold = 1 - brightnessCurve + 0.6;
return saturate((pattern - threshold) * contrast + baseVal);
}
void main()
{
// setup
float testRadius = 30.0;
float testSpeed = 1.0;
vec3 testOffset = vec3(0.0, 0.0, 50.0);
vec3 lightPos = vec3(sin(u_time.x * testSpeed) * testRadius, 5.0, cos(u_time.x * testSpeed) * testRadius);
vec3 texColor = u_dotColor.x > 0.1 ? u_dotColor.xyz : texture2D(s_texColor, v_uv0).xyz;
// lighting
// float brightness = calcBrightness(lightPos, v_wpos, v_normal);
float brightness = lerp(0.5, 0.9, calcBrightnessDirectional(vec3(0.5, 0.3, 1.0), v_normal));
// float brightness = 0.5;
// brightness = lerp(0.2, 1.0, sin(u_time.x) * 0.5 + 0.5);
float r = dither(brightness * texColor.r, v_uv0);
float g = dither(brightness * texColor.g, v_uv0);
float b = dither(brightness * texColor.b, v_uv0);
// vec3 finalColor = vec3(r, g, b);
vec3 ditheredColor = dither(brightness, v_uv0);
vec3 finalColor = mix(u_baseColor, texColor, ditheredColor);
gl_FragColor = vec4(finalColor, 1.0);
}