optimize cache_get n shiet

text_rendering/Makefile

@@ -14,4 +14,4 @@ util.o: util.c util.h
 test:  cache.o font.o hash.o main.o ren.o util.o
 	${CC} ${LDFLAGS} -o test  cache.o font.o hash.o main.o ren.o util.o
 clean: 
-	rm -f  cache.o font.o hash.o main.o ren.o util.o
+	rm -f test  cache.o font.o hash.o main.o ren.o util.o

text_rendering/cache.c

@@ -70,24 +70,14 @@ unsigned int cache_get(void)
 {
 	uint32_t x = 0;
 	// find an open spot in the cache
-	// TODO: use __builtin_clz to speed this up
-	for (; x < CACHE_SIZE; x++) {
-		//printf("testing spot %d\n", x);
-		//print_byte(bitmap[0]>>56);
-		//print_byte(bitmap[0]>>48);
-		//print_byte(bitmap[0]>>40);
-		//print_byte(bitmap[0]>>32);
-		//print_byte(bitmap[0]>>24);
-		//print_byte(bitmap[0]>>16);
-		//print_byte(bitmap[0]>>8);
-		//print_byte(bitmap[0]);
-		//printf("%lx", bitmap[i]);
-		//printf("\n");
-
-		if (!B_TEST(x))
-			break;
+	for (int b = 0; b < _BSIZE; b++) {
+		if (bitmap[b] == 0) x = 64;
+		else                x = __builtin_clzll(bitmap[b]);
+		x = 64-x;
+		if (!B_TEST(x+64*b))
+			return x+64*b;
 	}
-	return x;
+	return 0;
 }
 
 

text_rendering/font.c

@@ -46,7 +46,8 @@ struct font_atlas * font_init(void)
 
 
 // loads a font into memory, storing all the ASCII characters in the atlas, each font
-// atlas structure holds glyphs of a specific size
+// atlas structure holds glyphs of a specific size in pixels
+// NOTE: size includes ascend and descend (so 12 does not mean that 'A' is 12px tall)
 int font_load(struct font_atlas *atlas, const char *path, int size)
 {
 	if (!atlas || !path)
@@ -62,9 +63,9 @@ int font_load(struct font_atlas *atlas, const char *path, int size)
 	int ascent, descent, linegap, baseline;
 	int x0,y0,x1,y1;
 	float scale;
-	scale = stbtt_ScaleForPixelHeight(&(PRIV(atlas)->stb), size);
 	stbtt_GetFontVMetrics(&(PRIV(atlas)->stb), &ascent, &descent, &linegap);
 	stbtt_GetFontBoundingBox(&(PRIV(atlas)->stb), &x0, &y0, &x1, &y1);
+	scale = stbtt_ScaleForPixelHeight(&(PRIV(atlas)->stb), size);
 	baseline = scale * -y0;
 	atlas->glyph_max_w = (scale*x1) - (scale*x0);
 	atlas->glyph_max_h = (baseline+scale*y1) - (baseline+scale*y0);

text_rendering/genmake.sh

@@ -31,7 +31,7 @@ done
 mainrule='test: '
 linkcmd='	${CC} ${LDFLAGS} -o test '
 cleanrule='clean: 
-	rm -f '
+	rm -f test '
 while IFS="" read -r line; do
 	mainrule="$mainrule $line"
 	linkcmd="$linkcmd $line"

text_rendering/main.c

@@ -26,7 +26,7 @@ int main(void)
 		return 1;
 	}
 
-	const char *str = "Ciao Mamma!\nprova: òçà°ù§|¬³¼$£ì";
+	const char *str = "Ciao Mamma!\nprova: òçà°ù§|¬³¼$£ì\t";
 
 	SDL_Event e;
 	while(1) {
@@ -38,11 +38,11 @@ int main(void)
 			case SDL_WINDOWEVENT_RESIZED:
 			case SDL_WINDOWEVENT_SIZE_CHANGED:
 				ren_update_viewport(e.window.data1, e.window.data2);
-				ren_render_text(str, 0, 0, 100, 100, 12);
+				ren_render_text(str, 0, 0, 200, 100, 12);
 				SDL_GL_SwapWindow(win);
 				break;
 			case SDL_WINDOWEVENT_EXPOSED:
-				ren_render_text(str, 0, 0, 100, 100, 12);
+				ren_render_text(str, 0, 0, 200, 100, 12);
 				SDL_GL_SwapWindow(win);
 				break;
 			default: break;

text_rendering/ren.c

@@ -391,7 +391,7 @@ static int ren_draw_font_stack(void)
 	GL(glScissor(0, 0, ren.width, ren.height))
 	GL(glClear(GL_COLOR_BUFFER_BIT));
 	// this has caused me some trouble, convert from image coordiates to viewport
-	//GL(glScissor(ren.s_x, ren.height-ren.s_y-ren.s_h, ren.s_w, ren.s_h))
+	GL(glScissor(ren.s_x, ren.height-ren.s_y-ren.s_h, ren.s_w, ren.s_h))
 	GL(glUniform2i(ren.viewsize_loc, ren.width, ren.height))
 	GL(glUniform2i(ren.texturesize_loc, ren.font->width, ren.font->height))
 
@@ -480,9 +480,9 @@ int ren_render_text(const char *str, int x, int y, int w, int h, int size)
 	uint_least32_t cp;
 	int updated, gx = x, gy = y;
 	struct v_text v;
-	printf("rendering text: %s\n", str);
 	for (off = 0; (ret = grapheme_decode_utf8(str+off, SIZE_MAX, &cp)) > 0 && cp != 0; off += ret) {
 		// skip special characters that render a box (not present in font)
+		// FIXME: handle tab
 		if (iscntrl(cp)) goto skip_render;
 		g = font_get_glyph_texture(ren.font, cp, &updated);
 		if (!g) REN_RET(-1, REN_FONT);
@@ -531,9 +531,8 @@ int ren_render_text(const char *str, int x, int y, int w, int h, int size)
 		vtstack_push(&ren.font_stack, &v);
 
 		// TODO: possible kerning needs to be applied here
-		// FIXME: advance is too large
-		//gx += c.w + c.a;
-		//gx += c.w + c.x + 1;
+		// TODO: handle other unicode control characters such as the 
+		//       right-to-left isolate (\u2067)
 		gx += c.x + c.a;
 		skip_render:
 		switch (cp) {
@@ -542,7 +541,7 @@ int ren_render_text(const char *str, int x, int y, int w, int h, int size)
 			break;
 		case '\n':
 			// TODO: encode and/or store line height
-			gy = ren.font->glyph_max_h;
+			gy += ren.font->glyph_max_h;
 			gx = x;
 			break;
 		default: break;