webgpu support

implementations/Crafter.Graphics-UI-Shared.cpp

@@ -0,0 +1,86 @@
+/*
+Crafter®.Graphics
+Copyright (C) 2026 Catcrafts®
+catcrafts.net
+*/
+
+// Backend-agnostic UIRenderer methods. FillHeader and ShapeText do not
+// touch any GPU API; they only read window dimensions and (for ShapeText)
+// the CPU-side font atlas. Split out so both Vulkan and WebGPU impls
+// share the same source.
+
+module Crafter.Graphics:UI_shared_impl;
+import :UI;
+import :Window;
+import :Font;
+import :FontAtlas;
+import :GraphicsTypes;
+import std;
+
+using namespace Crafter;
+
+UIDispatchHeader UIRenderer::FillHeader(std::uint32_t itemBufferSlot,
+                                        std::uint32_t itemCount,
+                                        std::array<float,4> clipRectPx,
+                                        std::uint32_t flags) const noexcept {
+    UIDispatchHeader h{};
+    h.outImage      = outImageSlot_;
+    h.itemBuffer    = itemBufferSlot;
+    h.surfaceWidth  = window_->width;
+    h.surfaceHeight = window_->height;
+    h.clipX = clipRectPx[0];
+    h.clipY = clipRectPx[1];
+    h.clipW = clipRectPx[2];
+    h.clipH = clipRectPx[3];
+    h.itemCount = itemCount;
+#ifndef CRAFTER_GRAPHICS_WINDOW_DOM
+    h.frameIdx  = window_->currentBuffer;
+#else
+    h.frameIdx  = 0;
+#endif
+    h.flags     = flags;
+    h._pad      = 0;
+    return h;
+}
+
+std::uint32_t UIRenderer::ShapeText(Font& font, float pxSize,
+                                    float x, float baselineY,
+                                    std::string_view utf8,
+                                    std::array<float,4> color,
+                                    GlyphItem* out, std::uint32_t outCapacity,
+                                    float* outAdvance) {
+    if (fontAtlas == nullptr) {
+        std::println("UIRenderer::ShapeText: no FontAtlas (set fontAtlas before Initialize)");
+        std::abort();
+    }
+
+    const float scale = pxSize / FontAtlas::kBaseSize;
+    float cursor = x;
+    std::uint32_t written = 0;
+
+    std::size_t i = 0;
+    while (i < utf8.size() && written < outCapacity) {
+        std::uint32_t cp = DecodeUtf8(utf8, i);
+        if (cp == 0) break;
+        if (cp == '\n') { continue; }
+
+        fontAtlas->Ensure(font, cp);
+        const Glyph* g = fontAtlas->Lookup(font, cp);
+        if (g == nullptr) continue;
+
+        if (g->w > 0 && g->h > 0) {
+            GlyphItem& gi = out[written++];
+            gi.x  = cursor + g->xoff * scale;
+            gi.y  = baselineY + g->yoff * scale;
+            gi.w  = g->w * scale;
+            gi.h  = g->h * scale;
+            gi.u0 = g->u0; gi.v0 = g->v0;
+            gi.u1 = g->u1; gi.v1 = g->v1;
+            gi.r = color[0]; gi.g = color[1]; gi.b = color[2]; gi.a = color[3];
+        }
+        cursor += g->advance * scale;
+    }
+
+    if (outAdvance) *outAdvance = cursor - x;
+    return written;
+}