Merge remote-tracking branch 'origin/master' into claude/issue-57

# Conflicts:
#	project.cpp

implementations/Crafter.Graphics-Font.cpp

@@ -87,6 +87,28 @@ std::uint32_t Font::GetLineWidth(const std::string_view text, float size) {
     return lineWidth;
 }
 
+std::size_t Font::NearestCursorByte(std::string_view text, float size, float target) {
+    if (target <= 0.0f) return 0;
+    float scale = stbtt_ScaleForPixelHeight(&font, size);
+    std::size_t best     = 0;        // byte offset 0 → caret before the first glyph
+    float       bestDist = target;   // |target - 0|, and target > 0 here
+    float       cumWidth = 0.0f;
+    std::size_t i = 0;
+    while (i < text.size()) {
+        std::uint32_t cp = DecodeUtf8(text, i);   // i advances to the next boundary
+        if (cp == 0) break;
+        cumWidth += (int)(AdvanceUnits(cp) * scale);  // match GetLineWidth's per-glyph rounding
+        float d = std::abs(target - cumWidth);
+        if (d < bestDist) {
+            bestDist = d;
+            best     = i;            // byte offset just past this codepoint
+        } else {
+            break;                   // monotonic advance ⇒ already past the closest boundary
+        }
+    }
+    return best;
+}
+
 float Font::LineHeight(float size) {
     float scale = stbtt_ScaleForPixelHeight(&font, size);
     return (ascent - descent + lineGap) * scale;

implementations/Crafter.Graphics-InputField.cpp

@@ -117,23 +117,12 @@ std::size_t Crafter::InputField_HitTestCursor(const InputField& f,
                                               Font& font, float fontSize,
                                               const InputFieldColors& colors)
 {
+    // Single O(n) cumulative-advance pass over the value, keyed at codepoint
+    // byte boundaries — matching cursorPos, which is a byte offset. The old
+    // loop re-walked the prefix for every boundary (O(n^2) glyph metric
+    // lookups) and could even land mid-codepoint on multibyte input.
     float target = clickX - (rect.x + colors.paddingX);
-    if (target <= 0.0f) return 0;
-
-    std::size_t best     = 0;
-    float       bestDist = std::abs(target);
-    for (std::size_t i = 1; i <= f.value.size(); ++i) {
-        std::string_view sub(f.value.data(), i);
-        float w = static_cast<float>(font.GetLineWidth(sub, fontSize));
-        float d = std::abs(target - w);
-        if (d < bestDist) {
-            bestDist = d;
-            best     = i;
-        } else {
-            break;
-        }
-    }
-    return best;
+    return font.NearestCursorByte(f.value, fontSize, target);
 }
 
 void Crafter::DrawInputField(UIBuffer& buf, const InputField& f, Rect rect,

implementations/Crafter.Graphics-UI-Shared.cpp

@@ -38,11 +38,27 @@ UIDispatchHeader UIRenderer::FillHeader(std::uint32_t itemBufferSlot,
 #else
     h.frameIdx  = 0;
 #endif
-    h.flags     = flags;
+    h.flags     = ClipFlags(clipRectPx, window_->width, window_->height, flags);
     h._pad      = 0;
     return h;
 }
 
+std::uint32_t UIRenderer::ClipFlags(std::array<float,4> clipRectPx,
+                                    std::uint32_t surfaceWidth,
+                                    std::uint32_t surfaceHeight,
+                                    std::uint32_t flags) noexcept {
+    // The reserved kUIFlagClip bit signals "clip rect is narrower than the
+    // surface". When the rect already covers the whole surface (the common
+    // {0,0,1e9,1e9} default), the four per-pixel clip compares in
+    // uiResolveScreenPixel can never reject an in-surface pixel, so we leave
+    // the bit clear and the shader skips them — pixel-identical output.
+    const bool clipCoversSurface =
+        clipRectPx[0] <= 0.0f && clipRectPx[1] <= 0.0f
+        && clipRectPx[0] + clipRectPx[2] >= static_cast<float>(surfaceWidth)
+        && clipRectPx[1] + clipRectPx[3] >= static_cast<float>(surfaceHeight);
+    return clipCoversSurface ? (flags & ~kUIFlagClip) : (flags | kUIFlagClip);
+}
+
 std::uint32_t UIRenderer::ShapeText(Font& font, float pxSize,
                                     float x, float baselineY,
                                     std::string_view utf8,