From 67893dc14d10f49a76652ff384ab2bf4a945ca30 Mon Sep 17 00:00:00 2001
From: Nathan Reiner <nathan@nathanreiner.xyz>
Date: Sat, 22 Apr 2023 13:29:56 +0200
Subject: add glyph caching

---
 drw.c | 95 +++++++++++++++++++++++++++++++++++++++----------------------------
 1 file changed, 56 insertions(+), 39 deletions(-)

(limited to 'drw.c')

diff --git a/drw.c b/drw.c
index 6683cdb..307e942 100644
--- a/drw.c
+++ b/drw.c
@@ -158,7 +158,7 @@ free_drw(Canvas *canvas)
 void
 push_buffer(Canvas *canvas)
 {
-	memcpy(canvas->buffer_data, canvas->data, canvas->size);
+	//memcpy(canvas->buffer_data, canvas->data, canvas->size);
 }
 
 
@@ -168,7 +168,7 @@ draw_point(Canvas *canvas, unsigned x, unsigned y, uint32_t color)
 	if (!(x < canvas->width && y < canvas->height))
 		return;
 
-	canvas->data[x + canvas->width * y] = color;
+	canvas->buffer_data[x + canvas->width * y] = color;
 }
 
 
@@ -299,6 +299,7 @@ init_font(Font *font)
 	FT_Stroker_New(font->library, &font->stroke);
 
 	font->loaded = 1;
+	memset(font->cache, 0, CACHE_SIZE);
 }
 
 
@@ -329,7 +330,7 @@ draw_bitmap(Canvas *canvas, FT_Bitmap *bitmap, unsigned x, unsigned y, uint32_t
 				continue;
 			}
 
-			bg = to_color(canvas->data[i + j * canvas->width]);
+			bg = to_color(canvas->buffer_data[i + j * canvas->width]);
 			strength = bitmap->buffer[p + q * bitmap->width];
 			strength /= 255;
 
@@ -379,59 +380,75 @@ get_font_with_charcode(FontCache *fontcache, uint_least32_t charcode)
 }
 
 
-unsigned
-draw_char(Canvas *canvas, FontCache *fontcache, uint_least32_t charcode, unsigned x, unsigned y, uint32_t color)
+FT_BitmapGlyph
+load_bitmap(Font *font, uint_least32_t charcode)
 {
-	FT_GlyphSlot slot;
-	FT_Error error;
-	FT_UInt glyph_index;
-	FT_UInt previous = 0;
 	FT_Bool has_kerning;
 	FT_Vector delta;
-	Font *font;
+	FT_UInt glyph_index;
+	FT_Error error;
+	FT_GlyphSlot slot;
 	FT_BitmapGlyph bg;
 	FT_Glyph glyph;
 
-	font = get_font_with_charcode(fontcache, charcode);
-	FT_Set_Pixel_Sizes(font->face, 0, fontcache->fontsize);
+	slot = font->face->glyph;
+	glyph_index = FT_Get_Char_Index(font->face, charcode);
 
-	if (boldstokemode && fontcache->fonttype == FONT_BOLD) {
-		FT_Stroker_Set(font->stroke, fontcache->fontsize * 2, FT_STROKER_LINECAP_ROUND, FT_STROKER_LINEJOIN_ROUND, fontcache->fontsize * 2);
+	if (glyph_index >= CACHE_SIZE || font->cache[glyph_index] == 0) {
+		has_kerning = FT_HAS_KERNING(font->face);
+		if (has_kerning && glyph_index) {
+			FT_Get_Kerning(font->face, 0, glyph_index, FT_KERNING_DEFAULT, &delta);
+		}
 
-		y -= fontcache->fontsize * 2 / 64 + 1;
+		error = FT_Load_Glyph(font->face, glyph_index, FT_LOAD_DEFAULT);
+		if (error) {
+			fprintf(stderr, "warning: char not loaded, skipping...\n");
+			return 0;
+		}
+
+		FT_Get_Glyph(slot, &glyph);
+		FT_Glyph_StrokeBorder(&glyph, font->stroke, 0, 1);
+		if (error) {
+			fprintf(stderr, "warning: could not apply stroke\n");
+			return 0;
+		}
+
+		FT_Glyph_To_Bitmap(&glyph, FT_RENDER_MODE_NORMAL, 0, 1);
+		bg = (FT_BitmapGlyph)glyph;
+
+		if (glyph_index >= CACHE_SIZE) {
+			FT_Done_Glyph(glyph);
+		} else {
+			font->cache[glyph_index] = bg;
+		}
 	} else {
-		FT_Stroker_Set(font->stroke, 0, FT_STROKER_LINECAP_ROUND, FT_STROKER_LINEJOIN_ROUND, 0);
+		bg = font->cache[glyph_index];
 	}
 
-	slot = font->face->glyph;
-	glyph_index = FT_Get_Char_Index(font->face, charcode);
+	return bg;
+}
 
-	has_kerning = FT_HAS_KERNING(font->face);
-	if (has_kerning && previous && glyph_index) {
-		FT_Get_Kerning(font->face, previous, glyph_index, FT_KERNING_DEFAULT, &delta);
-		x += delta.x >> 6;
-	}
+void
+draw_char(Canvas *canvas, FontCache *fontcache, uint_least32_t charcode, unsigned x, unsigned y, uint32_t color)
+{
+	Font *font;
+	FT_BitmapGlyph bg;
 
-	error = FT_Load_Glyph(font->face, glyph_index, FT_LOAD_DEFAULT);
-	if (error) {
-		fprintf(stderr, "warning: char not loaded, skipping...\n");
-		return x;
-	}
+	font = get_font_with_charcode(fontcache, charcode);
+	FT_Set_Pixel_Sizes(font->face, 0, fontcache->fontsize);
 
-	FT_Get_Glyph(slot, &glyph);
-	FT_Glyph_StrokeBorder(&glyph, font->stroke, 0, 1);
-	if (error) {
-		fprintf(stderr, "warning: could not apply stroke\n");
-		return x;
+	if (boldstokemode && fontcache->fonttype == FONT_BOLD) {
+		FT_Stroker_Set(font->stroke, fontcache->fontsize * 2, FT_STROKER_LINECAP_BUTT, FT_STROKER_LINEJOIN_ROUND, fontcache->fontsize * 2);
+		y -= fontcache->fontsize * 2 / 64 + 1;
+	} else {
+		FT_Stroker_Set(font->stroke, 0, FT_STROKER_LINECAP_BUTT, FT_STROKER_LINEJOIN_ROUND, 0);
 	}
 
-	FT_Glyph_To_Bitmap(&glyph, FT_RENDER_MODE_NORMAL, 0, 1);
-	bg = (FT_BitmapGlyph)glyph;
-	draw_bitmap(canvas, &bg->bitmap, x + bg->left, y - bg->top, color);
-	FT_Done_Glyph(glyph);
+	bg = load_bitmap(font, charcode);
 
-	x += fontcache->box.width >> 6;
+	if (bg == 0)
+		return;
 
-	return x;
+	draw_bitmap(canvas, &bg->bitmap, x + bg->left, y - bg->top, color);
 }
 
-- 
cgit v1.2.3-70-g09d2