sdl ui backend

1 files changed, 41 insertions, 0 deletions

diff --git a/vendor/stb/font.h b/vendor/stb/font.h
new file mode 100644
index 00000000..93bbac8d
--- /dev/null
+++ b/vendor/stb/font.h
@@ -0,0 +1,41 @@
+// Tiny C shim over stb_truetype, so ui_sdl.zig can @cInclude a small header
+// instead of feeding the whole single-header lib to translate-c. The
+// implementation (font.c) pulls in stb_truetype.h (declarations only —
+// stb_truetype_impl.c defines STB_TRUETYPE_IMPLEMENTATION once elsewhere).
+//
+// A "font" is an opaque handle owning a stbtt_fontinfo; all rasterization goes
+// through these functions so the Zig side never touches stb internals.
+#ifndef UI_FONT_H
+#define UI_FONT_H
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct UIFont UIFont;
+
+// Parse the embedded TTF. `data` must stay alive for the lifetime of the font.
+// Returns NULL on failure.
+UIFont *ui_font_new(const uint8_t *data, int32_t len);
+
+// Font metrics at a given pixel height. cell_w is the monospace advance (rounded
+// up); ascent is the baseline offset from the top of a cell.
+float ui_font_scale_for_height(UIFont *f, float px);
+void ui_font_cell_metrics(UIFont *f, float scale, int32_t *cell_w, int32_t *cell_h, int32_t *ascent);
+
+// Rasterize `cp` into `out` (a cell_w*cell_h single-channel mask, row-major,
+// `stride` bytes per row). The glyph is positioned for a monospace cell: origin
+// at the baseline `ascent` pixels from the top. Pixels outside the glyph are 0.
+// Returns 1 if the glyph produced any coverage (0 for an empty/missing glyph,
+// but `out` is still zeroed).
+int ui_font_raster(UIFont *f, float scale, int32_t cp,
+                   uint8_t *out, int32_t stride, int32_t cell_w, int32_t cell_h,
+                   int32_t ascent);
+
+void ui_font_free(UIFont *f);
+
+#ifdef __cplusplus
+}
+#endif
+#endif