vtgl

Commit: 6a78f908852974118c8ac9e644da87bfbaccf866
Parent: d538eba43dab4578427d7ada3db0542b50e54e22
Author: Randy Palamar
Date:   Wed, 13 Nov 2024 07:18:42 -0700

font: compress width/height calculations

Diffstat:
M
config.def.h
 | 
2
+-
M
font.c
 | 
51
+++++++++++++++++++++++++--------------------------
M
util.h
 | 
14
+++++++-------

3 files changed, 33 insertions(+), 34 deletions(-)
diff --git a/config.def.h b/config.def.h
@@ -1,5 +1,5 @@
 /* See LICENSE for copyright details */
-static FontDesc g_fonts[][FS_LAST] = {
+static FontDesc g_fonts[][FS_COUNT] = {
 	{
 	[FS_NORMAL]      = {.path = "/usr/share/fonts/gofont/Go-Mono.ttf",             .height = 24},
 	[FS_BOLD]        = {.path = "/usr/share/fonts/gofont/Go-Mono-Bold.ttf",        .height = 24},
diff --git a/font.c b/font.c
@@ -48,7 +48,6 @@ cached_glyph_to_uv(FontAtlas *fa, CachedGlyph *cg, v2 *start, v2 *end, v2 scale)
 {
 	v2 cs = {.w = fa->info.w, .h = fa->info.h};
 	uv2 tile_coord = unpack_gpu_tile_coord(cg->gpu_tile_index);
-
 	f32 min_x = tile_coord.x * cs.w + cg->x0;
 	f32 max_x = min_x + cg->width;
 	f32 min_y = tile_coord.y * cs.h + fa->info.h + cg->y0 - fa->info.baseline;
@@ -278,12 +277,13 @@ render_glyph(Arena *a, FontAtlas *fa, u32 cp, u32 font_id, enum face_style style
 	for (u32 i = 0; i < cg->tile_count; i++)
 		gc->occupied_tiles[tile_index + i] = 1;
 
+	i32 out_y = (fa->info.h + y0 - fa->info.baseline) * out_width;
+	ASSERT(out_y >= 0);
 	ASSERT(x0 + FONT_H_PADDING >= 0);
 
 	rgba_bitmap = alloc(a, u32, out_size);
-	u32 out_y  = (fa->info.h + y0 - fa->info.baseline) * out_width;
 	for (i32 i = 0; i < height; i++) {
-		u32 out_x = x0 + FONT_H_PADDING;
+		i32 out_x = x0 + FONT_H_PADDING;
 		for (i32 j = 0; j < width; j++) {
 			/* TODO: handled coloured glyphs */
 			u32 pixel = 0;
@@ -303,6 +303,21 @@ end:
 	return rgba_bitmap;
 }
 
+static FontInfo
+compute_font_info(Font *font, f32 scale)
+{
+	FontInfo result;
+
+	i32 x0, x1, y0, y1;
+	stbtt_GetFontBoundingBox(&font->font_info, &x0, &y0, &x1, &y1);
+
+	result.h        = (u32)(scale * (y1 - y0)) + 1;
+	result.w        = (u32)(scale * (x1 - x0)) + 1 + FONT_H_PADDING;
+	result.baseline = (u32)(-scale * y0) + 1 + FONT_BASELINE_EXTRA;
+
+	return result;
+}
+
 static void
 font_atlas_update(FontAtlas *fa, iv2 glyph_bitmap_dim)
 {
@@ -317,20 +332,7 @@ font_atlas_update(FontAtlas *fa, iv2 glyph_bitmap_dim)
 
 	Font *font = &fa->fonts[0][FS_BOLD];
 	if (!font) font = &fa->fonts[0][FS_NORMAL];
-	i32 x0, x1, y0, y1;
-	stbtt_GetFontBoundingBox(&font->font_info, &x0, &y0, &x1, &y1);
-	f32 scale         = font->stbtt_scale;
-	fa->info.h        = (u32)(scale * (y1 - y0)) + 1;
-	fa->info.w        = (u32)(scale * (x1 - x0)) + 1 + FONT_H_PADDING;
-	fa->info.baseline = (u32)(-scale * y0) + 1 + FONT_BASELINE_EXTRA;
-
-	ASSERT(FONT_H_PADDING >= (i32)ABS(x0 * scale));
-
-	/* NOTE: sometimes the reported width is wrong; try '_' which is often the widest char */
-	i32 glyph_idx = stbtt_FindGlyphIndex(&font->font_info, '_');
-	stbtt_GetGlyphBitmapBoxSubpixel(&font->font_info, glyph_idx, scale, scale, 0, 0,
-	                                &x0, &y0, &x1, &y1);
-	if (x1 - x0 > fa->info.w) fa->info.w = x1 - x0;
+	fa->info = compute_font_info(font, font->stbtt_scale);
 
 	gc->tiles_in_x = (glyph_bitmap_dim.x - 1) / fa->info.w - 1;
 	gc->tiles_in_y = (glyph_bitmap_dim.y - 1) / fa->info.h - 1;
@@ -346,7 +348,7 @@ static void
 shift_font_sizes(FontAtlas *fa, i32 size_delta)
 {
 	for (u32 i = 0; i < fa->nfonts; i++) {
-		for (u32 j = 0; j < FS_LAST; j++) {
+		for (u32 j = 0; j < FS_COUNT; j++) {
 			Font *f = &fa->fonts[i][j];
 			if (!f->buf) continue;
 
@@ -365,7 +367,7 @@ init_fonts(FontAtlas *fa, Arena *a, iv2 glyph_bitmap_dim)
 	fa->fonts  = alloc(a, typeof(*fa->fonts), ARRAY_COUNT(g_fonts));
 	for (u32 j = 0; j < ARRAY_COUNT(g_fonts); j++) {
 		b32 result = 0;
-		for (u32 i = 0; i < FS_LAST; i++) {
+		for (u32 i = 0; i < FS_COUNT; i++) {
 			if (!g_fonts[j][i].path)
 				continue;
 			if (init_font(&fa->fonts[fa->nfonts][i], &g_fonts[j][i])) {
@@ -383,13 +385,10 @@ init_fonts(FontAtlas *fa, Arena *a, iv2 glyph_bitmap_dim)
 		os_fatal(s8("failed to load any fonts!\n"));
 
 	Font *f = &fa->fonts[0][FS_NORMAL];
-	i32 x0, x1, y0, y1;
-	f32 scale = stbtt_ScaleForPixelHeight(&f->font_info, MIN_FONT_SIZE);
-	stbtt_GetFontBoundingBox(&f->font_info, &x0, &y0, &x1, &y1);
-	f32 h = (u32)(scale * (y1 - y0)) + 1;
-	f32 w = (u32)(scale * (x1 - x0)) + 1 + FONT_H_PADDING;
-	i32 max_tiles_x = glyph_bitmap_dim.x / w;
-	i32 max_tiles_y = glyph_bitmap_dim.y / h;
+	FontInfo info   = compute_font_info(f, stbtt_ScaleForPixelHeight(&f->font_info,
+	                                                                 MIN_FONT_SIZE));
+	i32 max_tiles_x = glyph_bitmap_dim.x / info.w;
+	i32 max_tiles_y = glyph_bitmap_dim.y / info.h;
 
 	GlyphCache *gc     = &fa->glyph_cache;
 	gc->cache_len      = round_down_power_of_2(max_tiles_x * max_tiles_y);
diff --git a/util.h b/util.h
@@ -340,7 +340,7 @@ enum face_style {
 	FS_BOLD        = ATTR_BOLD,
 	FS_ITALIC      = ATTR_ITALIC,
 	FS_BOLD_ITALIC = ATTR_BOLD|ATTR_ITALIC,
-	FS_LAST,
+	FS_COUNT,
 	FS_MASK        = FS_BOLD_ITALIC,
 };
 
@@ -350,6 +350,11 @@ typedef struct {
 } FontDesc;
 
 typedef struct {
+	u32 h, w;
+	i32 baseline;
+} FontInfo;
+
+typedef struct {
 	stbtt_fontinfo  font_info;
 	u8             *buf;
 	i32             bufsize;
@@ -357,12 +362,7 @@ typedef struct {
 	f32             stbtt_scale;
 } Font;
 
-typedef Font FontFamily[FS_LAST];
-
-typedef struct {
-	u32 h, w;
-	i32 baseline;
-} FontInfo;
+typedef Font FontFamily[FS_COUNT];
 
 typedef struct {
 	u32 cp;