ok

cache/cache.c

@@ -1,73 +0,0 @@
-#define _POSIX_C_SOURCE 200809l
-#define _GNU_SOURCE
-
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <string.h>
-#include <search.h>
-
-#define CACHE_SIZE 512
-
-static struct hsearch_data hash_table;
-struct data {
-	unsigned int glyph;
-	unsigned int w, h, u, v;
-};
-static struct data cache_array[CACHE_SIZE] = {0};
-
-// bitmap size is aligned to word
-#define _BSIZE (CACHE_SIZE+0x3f)&(~0x3f)
-static uint64_t bitmap[_BSIZE] = {0};
-
-// bitmap operations
-#define B_RESET() memset(bitmap, 0, _BSIZE*sizeof(uint64_t))
-#define B_SET(x)  bitmap[(x)/_BSIZE] = 1<<((x)%_BSIZE)
-#define B_TEST(x) (bitmap[(x)/_BSIZE]&(1<<((x)%_BSIZE)))
-
-// reset the bitmap every n cycles
-#define NCYCLES (CACHE_SIZE/2)
-static int cycles = 0;
-
-
-void cache_init()
-{
-	hcreate_r(CACHE_SIZE, &hash_table);
-}
-
-
-void cache_destroy()
-{
-	hdestroy_r(&hash_table);
-}
-
-
-// d->glyph already contains the right glyph 
-struct data * cache_get(uint32_t glyph)
-{
-	static char gstr[5] = {0};
-	static ENTRY e, *r;
-	memcpy(gstr, &glyph, 4);
-	e.data = gstr;
-	hsearch_r(e, FIND, &r, &hash_table);
-	
-	// miss
-	if (!r)
-		return NULL;
-	
-	// hit
-	cycles = (cycles+1)%NCYCLES;
-	if (!cycles) B_RESET();
-	B_SET((struct data *)(r->data)-cache_array);
-	return (struct data *)(r->data);
-}
-
-
-int cache_insert(struct data *d)
-{
-	struct data *spot = NULL;
-	uint32_t x = 0;
-	for (; x < CACHE_SIZE; x++)
-		if (!B_TEST(x))
-			break;
-}

text_rendering/Makefile

@@ -1,6 +1,8 @@
 CC      = gcc
-LDFLAGS = -lm -lgrapheme -lSDL2 -lGLEW -lGL
-CFLAGS  = -ggdb3 -Wall -Wextra -pedantic -std=c11 -Wno-unused-function -fno-omit-frame-pointer
+# instrumentation flags
+INFLAGS = -fsanitize=address,builtin,undefined
+LDFLAGS = -lm -lgrapheme -lSDL2 -lGLEW -lGL ${INFLAGS}
+CFLAGS  = -ggdb3 -Wall -Wextra -pedantic -std=c11 -Wno-unused-function -fno-omit-frame-pointer ${INFLAGS}
 
 .PHONY: clean all
 all: test

text_rendering/font.c

@@ -151,7 +151,7 @@ const struct font_glyph * font_get_glyph_texture(struct font_atlas *atlas, unsig
 
 	// TODO: bounds check usign atlas height
 	// TODO: clear spot area in the atlas before writing on it
-	unsigned int spot = cache_get(&PRIV(atlas)->c);
+	unsigned int spot = cache_get_free_spot(&PRIV(atlas)->c);
 	unsigned int ty   = ((atlas->glyph_max_w * spot) / atlas->width) * atlas->glyph_max_h;
 	unsigned int tx   = (atlas->glyph_max_w * spot) % atlas->width;
 	unsigned int w    = atlas->width;
@@ -179,7 +179,7 @@ const struct font_glyph * font_get_glyph_texture(struct font_atlas *atlas, unsig
 		.y = off_y-base,
 		.a = adv,
 	};
-	return cache_insert(&PRIV(atlas)->c, &g, g.codepoint, spot);
+	return cache_insert_at(&PRIV(atlas)->c, &g, g.codepoint, spot);
 }
 
 

text_rendering/generic_cache.h

@@ -15,7 +15,7 @@
 //        as the code and not a generic type
 
 
-#define CACHE_USED(c, x)                                                       \
+#define CACHE_CYCLE(c)                                                         \
 {                                                                              \
 	if (++(c->cycles) > CACHE_NCYCLES) {                                   \
 		for (int i = 0; i < CACHE_BSIZE; i++) {                        \
@@ -24,7 +24,6 @@
 		}                                                              \
 		c->cycles = 0;                                                 \
 	}                                                                      \
-	CACHE_BSET(c->used, x);                                                \
 }
 
 
@@ -74,13 +73,14 @@ const type * name##_search(struct name *cache, uint32_t code)                  \
 	if (!CACHE_BTEST(cache->present, r->data))                             \
 		return NULL;                                                   \
 	/* HIT, set as recently used */                                        \
-	CACHE_USED(cache, r->data);                                            \
+	CACHE_BSET(cache->used, r->data);                                      \
 	return (&cache->array[r->data]);                                       \
 }                                                                              \
 \
 \
 /* Look for a free spot in the present bitmap and return its index */          \
-int name##_get(struct name *cache)                                             \
+/* If there is no free space left then just return the first position */       \
+int name##_get_free_spot(struct name *cache)                                   \
 {                                                                              \
 	if (!cache) return -1;                                                 \
 	int x = 0;                                                             \
@@ -95,18 +95,16 @@ int name##_get(struct name *cache)                                             \
 }                                                                              \
 \
 \
-const type * name##_insert(struct name *cache, const type *g, uint32_t code, int x)\
+const type * name##_insert_at(struct name *cache, const type *g, uint32_t code, int x)\
 {                                                                              \
 	if (!cache) return NULL;                                               \
 	type *spot = NULL;                                                     \
-	/* x is the index to the cache array, it has to come from the user */  \
-	/* check if the spot is free */                                        \
-	if (x < 0 || CACHE_BTEST(cache->present, x))                           \
-		return NULL;                                                   \
+	/* check if the spot is valid */                                       \
+	if (x < 0) return NULL;                                                \
 	/* Set used and present */                                             \
-	CACHE_USED(cache, x)                                                   \
 	CACHE_BSET(cache->present, x);                                         \
 	CACHE_BSET(cache->used, x);                                            \
+	CACHE_CYCLE(cache)                                                     \
 	spot = &(cache->array[x]);                                             \
 	*spot = *g;                                                            \
 	struct name##table_entry e = { .code = code, .data = x};               \
@@ -114,6 +112,15 @@ const type * name##_insert(struct name *cache, const type *g, uint32_t code, int
 		return NULL;                                                   \
 	return spot;                                                           \
 }                                                                              \
+\
+\
+const type * name##_insert(struct name *cache, const type *g, uint32_t code, int *x)\
+{                                                                              \
+	int y;                                                                 \
+	if (!x) x = &y;                                                        \
+	*x = name##_get_free_spot(cache);                                      \
+	return name##_insert_at(cache, g, code, *x);                           \
+}                                                                              \
 
 
 #endif

text_rendering/genmake.sh

@@ -15,9 +15,11 @@ rm -f objlist
 
 cat > Makefile << EOF
 CC      = gcc
-LDFLAGS = -lm -lgrapheme -lSDL2 -lGLEW -lGL
+# instrumentation flags
+INFLAGS = -fsanitize=address,builtin,undefined
+LDFLAGS = -lm -lgrapheme -lSDL2 -lGLEW -lGL \${INFLAGS}
 CFLAGS  = -ggdb3 -Wall -Wextra -pedantic -std=c11 \
--Wno-unused-function -fno-omit-frame-pointer
+-Wno-unused-function -fno-omit-frame-pointer \${INFLAGS}
 
 .PHONY: clean all
 all: test

text_rendering/main.c

@@ -20,25 +20,27 @@ const char *str2 = "The quick brown fox jumps over the lazy dog\n"
 SDL_Window *win;
 
 
+#define red  0xff0000ff
+#define blue 0xffff0000
 void draw(void)
 {
 	static unsigned int frame = 0;
 	printf("frame: %d\n", frame++);
 	ren_clear();
-	//ren_render_box(10, 10, 400, 50, 0xffff0000);
+	//ren_render_box(10, 10, 400, 50, blue);
 	//if (ren_render_text(str1, 10, 10, 400, 50, 20))
 	//	printf("text: %s\n", ren_strerror());
 	int w, h;
 	ren_get_text_box(str2, &w, &h, 20);
 	//printf("box for: %s -> (%d, %d)\n", str2, w, h);
-	ren_render_box(0, 0, w, h, 0xffff0000);
+	ren_render_box(0, 0, w, h, blue);
 	ren_render_text(str2, 0, 0, w, h, 20);
 
 	// fixme: this causes a bug
 	const char *s = "ciao mamma";
 	ren_get_text_box(s, &w, &h, 12);
 	s = "stuff that was not in font size 12 -> чащаx";
-	ren_render_box(0, 200, w, h, 0xff0000ff);
+	ren_render_box(0, 200, w, h, red);
 	if (ren_render_text(s, 0, 200, 0xffff, 0xffff, 12))
 		printf("BUG\n");