Crafter.Graphics/implementations/Crafter.Graphics-FontAtlas.cpp
2026-05-18 04:58:52 +02:00

141 lines
3.8 KiB
C++

/*
Crafter®.Graphics
Copyright (C) 2026 Catcrafts®
catcrafts.net
*/
module;
#ifndef CRAFTER_GRAPHICS_WINDOW_DOM
#include "vulkan/vulkan.h"
#endif
#include "../lib/stb_truetype.h"
module Crafter.Graphics:FontAtlas_impl;
import :FontAtlas;
import :Font;
import :GraphicsTypes;
#ifndef CRAFTER_GRAPHICS_WINDOW_DOM
import :ImageVulkan;
import :Device;
#else
import :WebGPU;
#endif
import std;
using namespace Crafter;
std::uint8_t* FontAtlas::PixelPtr() noexcept {
#ifndef CRAFTER_GRAPHICS_WINDOW_DOM
return image.buffer.value;
#else
return staging.data();
#endif
}
void FontAtlas::Initialize(GraphicsCommandBuffer cmd) {
#ifndef CRAFTER_GRAPHICS_WINDOW_DOM
image.Create(
kAtlasSize, kAtlasSize, /*mipLevels*/ 1, cmd,
VK_FORMAT_R8_UNORM,
VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_SAMPLED_BIT,
VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL
);
std::memset(image.buffer.value, 0, kAtlasSize * kAtlasSize);
dirty = true;
#else
(void)cmd;
staging.assign(kAtlasSize * kAtlasSize, 0);
textureHandle = WebGPU::wgpuCreateAtlasTexture(kAtlasSize, kAtlasSize);
dirty = true;
#endif
}
bool FontAtlas::ShelfPlace(int w, int h, int& outX, int& outY) {
for (Shelf& s : shelves_) {
if (h <= s.height && s.cursorX + w <= kAtlasSize) {
outX = s.cursorX;
outY = s.y;
s.cursorX += w;
return true;
}
}
if (nextShelfY_ + h > kAtlasSize) return false;
Shelf s{};
s.y = nextShelfY_;
s.height = h;
s.cursorX = w;
outX = 0;
outY = s.y;
shelves_.push_back(s);
nextShelfY_ += h;
return true;
}
bool FontAtlas::Ensure(Font& font, std::uint32_t codepoint) {
Key key{&font, codepoint};
if (cache_.contains(key)) return true;
float fontScale = stbtt_ScaleForPixelHeight(&font.font, kBaseSize);
int advanceUnits = 0, lsb = 0;
stbtt_GetCodepointHMetrics(&font.font, static_cast<int>(codepoint), &advanceUnits, &lsb);
int sw = 0, sh = 0, xoff = 0, yoff = 0;
unsigned char* sdf = stbtt_GetCodepointSDF(
&font.font, fontScale, static_cast<int>(codepoint),
kPadding, static_cast<unsigned char>(kOnEdgeValue), kPixelDistScale,
&sw, &sh, &xoff, &yoff
);
Glyph g{};
g.advance = advanceUnits * fontScale;
g.xoff = static_cast<float>(xoff);
g.yoff = static_cast<float>(yoff);
if (sdf && sw > 0 && sh > 0) {
int px = 0, py = 0;
if (!ShelfPlace(sw, sh, px, py)) {
stbtt_FreeSDF(sdf, nullptr);
return false;
}
std::uint8_t* dst = PixelPtr();
for (int row = 0; row < sh; ++row) {
std::memcpy(
dst + (py + row) * kAtlasSize + px,
sdf + row * sw,
static_cast<std::size_t>(sw)
);
}
stbtt_FreeSDF(sdf, nullptr);
g.w = static_cast<float>(sw);
g.h = static_cast<float>(sh);
g.u0 = static_cast<float>(px) / kAtlasSize;
g.v0 = static_cast<float>(py) / kAtlasSize;
g.u1 = static_cast<float>(px + sw) / kAtlasSize;
g.v1 = static_cast<float>(py + sh) / kAtlasSize;
dirty = true;
}
cache_.emplace(key, g);
return true;
}
const Glyph* FontAtlas::Lookup(Font& font, std::uint32_t codepoint) const {
auto it = cache_.find(Key{&font, codepoint});
return it == cache_.end() ? nullptr : &it->second;
}
void FontAtlas::Update(GraphicsCommandBuffer cmd) {
if (!dirty) return;
#ifndef CRAFTER_GRAPHICS_WINDOW_DOM
image.Update(cmd, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);
#else
(void)cmd;
// Full-atlas upload. Future: track dirty region.
WebGPU::wgpuWriteAtlasRegion(
textureHandle, staging.data(),
kAtlasSize, kAtlasSize, kAtlasSize,
0, 0, kAtlasSize, kAtlasSize
);
#endif
dirty = false;
}