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SRGB gamma correction #2440

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3d85d6a
srgb initial prototype
IntegratedQuantum Dec 28, 2025
8136f21
Use SRGB for the entire menu
IntegratedQuantum Dec 28, 2025
015614e
gamma correct light and absorption colors of blocks
IntegratedQuantum Dec 28, 2025
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7 changes: 6 additions & 1 deletion assets/cubyz/shaders/chunks/chunk_fragment.frag
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Expand Up @@ -51,12 +51,17 @@ vec4 fixedCubeMapLookup(vec3 v) { // Taken from http://the-witness.net/news/2012
return texture(reflectionMap, v);
}

float srgbToLinear(float srgbChannel) {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return pow((srgbChannel + 0.055)/1.055, 2.4);
}

void main() {
float animatedTextureIndex = animatedTexture[textureIndex];
float normalVariation = lightVariation(normal);
vec3 textureCoords = vec3(uv, animatedTextureIndex);

float reflectivity = texture(reflectivityAndAbsorptionSampler, textureCoords).a;
float reflectivity = srgbToLinear(texture(reflectivityAndAbsorptionSampler, textureCoords).a);
float fresnelReflection = (1 + dot(normalize(direction), normal));
fresnelReflection *= fresnelReflection;
fresnelReflection *= min(1, 2*reflectivity); // Limit it to 2*reflectivity to avoid making every block reflective.
Expand Down
17 changes: 15 additions & 2 deletions assets/cubyz/shaders/chunks/transparent_fragment.frag
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Expand Up @@ -130,6 +130,19 @@ vec4 fixedCubeMapLookup(vec3 v) { // Taken from http://the-witness.net/news/2012
return texture(reflectionMap, v);
}

float srgbToLinear(float srgbChannel) {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return pow((srgbChannel + 0.055)/1.055, 2.4);
}

vec3 srgbToLinear(vec3 srgb) {
return vec3(
srgbToLinear(srgb.r),
srgbToLinear(srgb.g),
srgbToLinear(srgb.b)
);
}

void main() {
float animatedTextureIndex = animatedTexture[textureIndex];
vec3 textureCoords = vec3(uv, animatedTextureIndex);
Expand All @@ -138,11 +151,11 @@ void main() {
float dist = zFromDepth(texelFetch(depthTexture, ivec2(gl_FragCoord.xy), 0).r);
float fogDistance = calculateFogDistance(dist, densityAdjustment, playerPositionFraction.z, normalize(direction).z, fogData[int(animatedTextureIndex)].fogDensity, 1e10, 1e10);
float airFogDistance = calculateFogDistance(dist, densityAdjustment, playerPositionFraction.z, normalize(direction).z, fog.density, fog.fogLower - playerPositionInteger.z, fog.fogHigher - playerPositionInteger.z);
vec3 fogColor = unpackColor(fogData[int(animatedTextureIndex)].fogColor);
vec3 fogColor = srgbToLinear(unpackColor(fogData[int(animatedTextureIndex)].fogColor));
vec3 pixelLight = max(light*normalVariation, texture(emissionSampler, textureCoords).r*4);
vec4 textureColor = texture(textureSampler, textureCoords)*vec4(pixelLight, 1);

float reflectivity = texture(reflectivityAndAbsorptionSampler, textureCoords).a;
float reflectivity = srgbToLinear(texture(reflectivityAndAbsorptionSampler, textureCoords).a);
float fresnelReflection = (1 + dot(normalize(direction), normal));
fresnelReflection *= fresnelReflection;
fresnelReflection *= min(1, 2*reflectivity); // Limit it to 2*reflectivity to avoid making every block reflective.
Expand Down
15 changes: 14 additions & 1 deletion assets/cubyz/shaders/graphics/Circle.vert
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Expand Up @@ -12,6 +12,19 @@ layout(location = 2) uniform vec2 screen;

layout(location = 3) uniform int circleColor;

float srgbToLinear(float srgbChannel) {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return pow((srgbChannel + 0.055)/1.055, 2.4);
}

vec3 srgbToLinear(vec3 srgb) {
return vec3(
srgbToLinear(srgb.r),
srgbToLinear(srgb.g),
srgbToLinear(srgb.b)
);
}

void main() {
// Convert to opengl coordinates:
vec2 position_percentage = (center + vertex_pos*radius)/screen;
Expand All @@ -20,7 +33,7 @@ void main() {

gl_Position = vec4(position, 0, 1);

color = vec4((circleColor & 0xff0000)>>16, (circleColor & 0xff00)>>8, circleColor & 0xff, (circleColor>>24) & 255)/255.0;
color = vec4(srgbToLinear(vec3((circleColor & 0xff0000)>>16, (circleColor & 0xff00)>>8, circleColor & 0xff)/255.0), float((circleColor>>24) & 255)/255.0);

unitPosition = vertex_pos;
}
15 changes: 14 additions & 1 deletion assets/cubyz/shaders/graphics/Image.vert
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Expand Up @@ -14,6 +14,19 @@ layout(location = 4) uniform vec2 uvDim;

layout(location = 5) uniform int color;

float srgbToLinear(float srgbChannel) {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return pow((srgbChannel + 0.055)/1.055, 2.4);
}

vec3 srgbToLinear(vec3 srgb) {
return vec3(
srgbToLinear(srgb.r),
srgbToLinear(srgb.g),
srgbToLinear(srgb.b)
);
}

void main() {
// Convert to opengl coordinates:
vec2 position_percentage = (start + vec2(vertex_pos.x*size.x, size.y - vertex_pos.y*size.y))/screen;
Expand All @@ -22,6 +35,6 @@ void main() {

gl_Position = vec4(position, 0, 1);

fColor = vec4((color & 0xff0000)>>16, (color & 0xff00)>>8, color & 0xff, (color>>24) & 255)/255.0;
fColor = vec4(srgbToLinear(vec3((color & 0xff0000)>>16, (color & 0xff00)>>8, color & 0xff)/255.0), float((color>>24) & 255)/255.0);
uv = uvOffset + vertex_pos*uvDim;
}
15 changes: 14 additions & 1 deletion assets/cubyz/shaders/graphics/Line.vert
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Expand Up @@ -11,6 +11,19 @@ layout(location = 2) uniform vec2 screen;

layout(location = 3) uniform int lineColor;

float srgbToLinear(float srgbChannel) {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return pow((srgbChannel + 0.055)/1.055, 2.4);
}

vec3 srgbToLinear(vec3 srgb) {
return vec3(
srgbToLinear(srgb.r),
srgbToLinear(srgb.g),
srgbToLinear(srgb.b)
);
}

void main() {
// Convert to opengl coordinates:
vec2 position_percentage = (start + vertex_pos*direction)/screen;
Expand All @@ -19,5 +32,5 @@ void main() {

gl_Position = vec4(position, 0, 1);

color = vec4((lineColor & 0xff0000)>>16, (lineColor & 0xff00)>>8, lineColor & 0xff, (lineColor>>24) & 255)/255.0;
color = vec4(srgbToLinear(vec3((lineColor & 0xff0000)>>16, (lineColor & 0xff00)>>8, lineColor & 0xff)/255.0), float((lineColor>>24) & 255)/255.0);
}
15 changes: 14 additions & 1 deletion assets/cubyz/shaders/graphics/Rect.vert
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Expand Up @@ -11,6 +11,19 @@ layout(location = 2) uniform vec2 screen;

layout(location = 3) uniform int rectColor;

float srgbToLinear(float srgbChannel) {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return pow((srgbChannel + 0.055)/1.055, 2.4);
}

vec3 srgbToLinear(vec3 srgb) {
return vec3(
srgbToLinear(srgb.r),
srgbToLinear(srgb.g),
srgbToLinear(srgb.b)
);
}

void main() {
// Convert to opengl coordinates:
vec2 position_percentage = (start + vertex_pos*size)/screen;
Expand All @@ -19,5 +32,5 @@ void main() {

gl_Position = vec4(position, 0, 1);

color = vec4((rectColor & 0xff0000)>>16, (rectColor & 0xff00)>>8, rectColor & 0xff, (rectColor>>24) & 255)/255.0;;
color = vec4(srgbToLinear(vec3((rectColor & 0xff0000)>>16, (rectColor & 0xff00)>>8, rectColor & 0xff)/255.0), float((rectColor>>24) & 255)/255.0);
}
15 changes: 14 additions & 1 deletion assets/cubyz/shaders/graphics/RectBorder.vert
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Expand Up @@ -12,6 +12,19 @@ layout(location = 3) uniform float lineWidth;

layout(location = 4) uniform int rectColor;

float srgbToLinear(float srgbChannel) {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return pow((srgbChannel + 0.055)/1.055, 2.4);
}

vec3 srgbToLinear(vec3 srgb) {
return vec3(
srgbToLinear(srgb.r),
srgbToLinear(srgb.g),
srgbToLinear(srgb.b)
);
}

void main() {
// Convert to opengl coordinates:
vec2 position_percentage = (start + vertex_pos.xy*size + vertex_pos.zw*lineWidth)/screen;
Expand All @@ -20,5 +33,5 @@ void main() {

gl_Position = vec4(position, 0, 1);

color = vec4((rectColor & 0xff0000)>>16, (rectColor & 0xff00)>>8, rectColor & 0xff, (rectColor>>24) & 255)/255.0;;
color = vec4(srgbToLinear(vec3((rectColor & 0xff0000)>>16, (rectColor & 0xff00)>>8, rectColor & 0xff)/255.0), float((rectColor>>24) & 255)/255.0);
}
15 changes: 14 additions & 1 deletion assets/cubyz/shaders/graphics/Text.vert
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Expand Up @@ -14,6 +14,19 @@ layout(location = 4) uniform int fontEffects;

layout(location = 5) uniform float alpha;

float srgbToLinear(float srgbChannel) {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return pow((srgbChannel + 0.055)/1.055, 2.4);
}

vec3 srgbToLinear(vec3 srgb) {
return vec3(
srgbToLinear(srgb.r),
srgbToLinear(srgb.g),
srgbToLinear(srgb.b)
);
}

vec2 convert2Proportional(vec2 original, vec2 full) {
return vec2(original.x/full.x, original.y/full.y);
}
Expand All @@ -33,5 +46,5 @@ void main() {

gl_Position = vec4(position, 0, 1);
frag_face_pos = face_pos;
color = vec4(vec3((fontEffects & 0xff0000)>>16, (fontEffects & 0xff00)>>8, fontEffects & 0xff)/255.0, alpha);
color = vec4(srgbToLinear(vec3((fontEffects & 0xff0000)>>16, (fontEffects & 0xff00)>>8, fontEffects & 0xff)/255.0), alpha);
}
1 change: 0 additions & 1 deletion assets/cubyz/shaders/graphics/graph.vert
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Expand Up @@ -12,7 +12,6 @@ layout(std430, binding = 5) buffer _data
float data[];
};


void main() {
float x = gl_VertexID;
float y = -data[(gl_VertexID+offset)%points];
Expand Down
14 changes: 14 additions & 0 deletions assets/cubyz/shaders/item_drop.frag
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Expand Up @@ -42,6 +42,19 @@ layout(std430, binding = 1) buffer _animatedTexture
float animatedTexture[];
};

float srgbToLinear(float srgbChannel) {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return pow((srgbChannel + 0.055)/1.055, 2.4);
}

vec3 srgbToLinear(vec3 srgb) {
return vec3(
srgbToLinear(srgb.r),
srgbToLinear(srgb.g),
srgbToLinear(srgb.b)
);
}

// block drops -------------------------------------------------------------------------------------------------------------------------

float lightVariation(vec3 normal) {
Expand Down Expand Up @@ -182,6 +195,7 @@ void mainItemDrop() {

fragColor = decodeColor(block);
fragColor.a = 1; // No transparency supported!
fragColor.rgb = srgbToLinear(fragColor.rgb);
fragColor = fragColor*vec4(ambientLight*normalVariations[lastNormal], 1);
}

Expand Down
18 changes: 13 additions & 5 deletions src/blocks.zig
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Expand Up @@ -27,6 +27,7 @@ const BlockTouchCallback = main.callbacks.BlockTouchCallback;
const sbb = main.server.terrain.structure_building_blocks;
const blueprint = main.blueprint;
const Assets = main.assets.Assets;
const Vec3f = main.vec.Vec3f;

pub const maxBlockCount: usize = 65536; // 16 bit limit

Expand Down Expand Up @@ -97,6 +98,13 @@ var size: u32 = 0;

pub var ores: main.ListUnmanaged(Ore) = .{};

pub fn transformLightFromSrgb(in: u32) u32 {
const srgb = @as(Vec3f, @floatFromInt(@Vector(3, u32){in >> 16 & 255, in >> 8 & 255, in & 255}))/@as(Vec3f, @splat(255));
const linear = main.graphics.srgbToLinear(srgb);
const bytes: @Vector(3, u8) = @intFromFloat(@round(linear*@as(Vec3f, @splat(255))));
return @as(u32, bytes[0]) << 16 | @as(u32, bytes[1]) << 8 | bytes[2];
}

pub fn register(_: []const u8, id: []const u8, zon: ZonElement) u16 {
_id[size] = main.worldArena.dupe(u8, id);
reverseIndices.put(main.worldArena.allocator, _id[size], @intCast(size)) catch unreachable;
Expand All @@ -117,8 +125,8 @@ pub fn register(_: []const u8, id: []const u8, zon: ZonElement) u16 {
}
}

_light[size] = zon.get(u32, "emittedLight", 0);
_absorption[size] = zon.get(u32, "absorbedLight", 0xffffff);
_light[size] = transformLightFromSrgb(zon.get(u32, "emittedLight", 0));
_absorption[size] = transformLightFromSrgb(zon.get(u32, "absorbedLight", 0xffffff));
_degradable[size] = zon.get(bool, "degradable", false);
_selectable[size] = zon.get(bool, "selectable", true);
_replacable[size] = zon.get(bool, "replacable", false);
Expand Down Expand Up @@ -766,9 +774,9 @@ pub const meshes = struct { // MARK: meshes

pub fn generateTextureArray() void {
const c = graphics.c;
blockTextureArray.generate(blockTextures.items, true, true);
blockTextureArray.generate(blockTextures.items, .srgb, true, true);
c.glTexParameterf(c.GL_TEXTURE_2D_ARRAY, c.GL_TEXTURE_MAX_ANISOTROPY, @floatFromInt(main.settings.anisotropicFiltering));
emissionTextureArray.generate(emissionTextures.items, true, false);
emissionTextureArray.generate(emissionTextures.items, .linear, true, false);
c.glTexParameterf(c.GL_TEXTURE_2D_ARRAY, c.GL_TEXTURE_MAX_ANISOTROPY, @floatFromInt(main.settings.anisotropicFiltering));
const reflectivityAndAbsorptionTextures = main.stackAllocator.alloc(Image, reflectivityTextures.items.len);
defer main.stackAllocator.free(reflectivityAndAbsorptionTextures);
Expand All @@ -787,7 +795,7 @@ pub const meshes = struct { // MARK: meshes
}
}
}
reflectivityAndAbsorptionTextureArray.generate(reflectivityAndAbsorptionTextures, true, false);
reflectivityAndAbsorptionTextureArray.generate(reflectivityAndAbsorptionTextures, .srgb, true, false);
c.glTexParameterf(c.GL_TEXTURE_2D_ARRAY, c.GL_TEXTURE_MAX_ANISOTROPY, @floatFromInt(main.settings.anisotropicFiltering));

// Also generate additional buffers:
Expand Down
27 changes: 22 additions & 5 deletions src/graphics.zig
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Expand Up @@ -2197,7 +2197,7 @@ pub const TextureArray = struct { // MARK: TextureArray
}

/// (Re-)Generates the GPU buffer.
pub fn generate(self: TextureArray, images: []Image, mipmapping: bool, alphaCorrectMipmapping: bool) void {
pub fn generate(self: TextureArray, images: []Image, transformFunction: enum{linear, srgb}, mipmapping: bool, alphaCorrectMipmapping: bool) void {
var maxWidth: u31 = 1;
var maxHeight: u31 = 1;
for(images) |image| {
Expand All @@ -2217,8 +2217,12 @@ pub const TextureArray = struct { // MARK: TextureArray
self.bind();

const maxLOD = if(mipmapping) 1 + std.math.log2_int(u31, @min(maxWidth, maxHeight)) else 1;
const format = switch(transformFunction) {
.linear => c.GL_RGBA8,
.srgb => c.GL_SRGB8_ALPHA8,
};
for(0..maxLOD) |i| {
c.glTexImage3D(c.GL_TEXTURE_2D_ARRAY, @intCast(i), c.GL_RGBA8, @max(0, maxWidth >> @intCast(i)), @max(0, maxHeight >> @intCast(i)), @intCast(images.len), 0, c.GL_RGBA, c.GL_UNSIGNED_BYTE, null);
c.glTexImage3D(c.GL_TEXTURE_2D_ARRAY, @intCast(i), format, @max(0, maxWidth >> @intCast(i)), @max(0, maxHeight >> @intCast(i)), @intCast(images.len), 0, c.GL_RGBA, c.GL_UNSIGNED_BYTE, null);
}
const arena = main.stackAllocator.createArena();
defer main.stackAllocator.destroyArena(arena);
Expand Down Expand Up @@ -2319,7 +2323,7 @@ pub const Texture = struct { // MARK: Texture

var curSize: u31 = largestSize;
while(curSize != 0) : (curSize /= 2) {
c.glTexImage2D(c.GL_TEXTURE_2D, maxLod - std.math.log2_int(u31, curSize), c.GL_RGBA8, curSize, curSize, 0, c.GL_RGBA, c.GL_UNSIGNED_BYTE, null);
c.glTexImage2D(c.GL_TEXTURE_2D, maxLod - std.math.log2_int(u31, curSize), c.GL_SRGB8_ALPHA8, curSize, curSize, 0, c.GL_RGBA, c.GL_UNSIGNED_BYTE, null);
}

curSize = largestSize;
Expand Down Expand Up @@ -2360,7 +2364,7 @@ pub const Texture = struct { // MARK: Texture
pub fn generate(self: Texture, image: Image) void {
self.bind();

c.glTexImage2D(c.GL_TEXTURE_2D, 0, c.GL_RGBA8, image.width, image.height, 0, c.GL_RGBA, c.GL_UNSIGNED_BYTE, image.imageData.ptr);
c.glTexImage2D(c.GL_TEXTURE_2D, 0, c.GL_SRGB8_ALPHA8, image.width, image.height, 0, c.GL_RGBA, c.GL_UNSIGNED_BYTE, image.imageData.ptr);
c.glTexParameteri(c.GL_TEXTURE_2D, c.GL_TEXTURE_MIN_FILTER, c.GL_NEAREST);
c.glTexParameteri(c.GL_TEXTURE_2D, c.GL_TEXTURE_MAG_FILTER, c.GL_NEAREST);
c.glTexParameteri(c.GL_TEXTURE_2D, c.GL_TEXTURE_WRAP_S, c.GL_REPEAT);
Expand Down Expand Up @@ -2699,7 +2703,7 @@ pub fn generateBlockTexture(blockType: u16) Texture {
c.glDisable(c.GL_CULL_FACE);
var finalFrameBuffer: FrameBuffer = undefined;
finalFrameBuffer.init(false, c.GL_NEAREST, c.GL_REPEAT);
finalFrameBuffer.updateSize(textureSize, textureSize, c.GL_RGBA8);
finalFrameBuffer.updateSize(textureSize, textureSize, c.GL_SRGB8_ALPHA8);
finalFrameBuffer.bind();
const texture = Texture{.textureID = finalFrameBuffer.texture};
defer c.glDeleteFramebuffers(1, &finalFrameBuffer.frameBuffer);
Expand All @@ -2716,3 +2720,16 @@ pub fn generateBlockTexture(blockType: u16) Texture {
c.glBlendFunc(c.GL_SRC_ALPHA, c.GL_ONE_MINUS_SRC_ALPHA);
return texture;
}

fn srgbChannelToLinear(srgbChannel: f32) f32 {
if(srgbChannel <= 0.04045) return srgbChannel/12.92;
return std.math.pow(f32, (srgbChannel + 0.055)/1.055, 2.4);
}

pub fn srgbToLinear(srgb: Vec3f) Vec3f {
return .{
srgbChannelToLinear(srgb[0]),
srgbChannelToLinear(srgb[1]),
srgbChannelToLinear(srgb[2]),
};
}
1 change: 1 addition & 0 deletions src/main.zig
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Expand Up @@ -608,6 +608,7 @@ pub fn clientMain() void { // MARK: clientMain()

const c = Window.c;
Window.GLFWCallbacks.framebufferSize(undefined, Window.width, Window.height);
c.glEnable(c.GL_FRAMEBUFFER_SRGB);
var lastBeginRendering = timestamp();

audio.setMusic("cubyz:TotalDemented/Cubyz");
Expand Down
4 changes: 2 additions & 2 deletions src/particles.zig
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Expand Up @@ -136,8 +136,8 @@ pub const ParticleManager = struct {
}

pub fn generateTextureArray() void {
textureArray.generate(textures.items, true, true);
emissionTextureArray.generate(emissionTextures.items, true, false);
textureArray.generate(textures.items, .srgb, true, true);
emissionTextureArray.generate(emissionTextures.items, .linear, true, false);

particleTypesSSBO.bufferData(ParticleType, ParticleManager.types.items);
particleTypesSSBO.bind(14);
Expand Down
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