something

text_rendering/Makefile

@@ -0,0 +1,7 @@
+LDFLAGS = -lm -lgrapheme
+CFLAGS = -g -Wall -Wextra -pedantic
+SOURCE = main.c font.c cache.c hash.c util.c
+HEADER = font.h hash.h cache.h util.h
+
+test: ${HEADER} ${SOURCE}
+	gcc ${CFLAGS} ${LDFLAGS} ${SOURCE} -o test

text_rendering/cache.c

@@ -79,7 +79,7 @@ unsigned int cache_get(void)
 
 
 // inserts the font glyph into the cache
-const struct font_glyph * cache_insert(struct font_glyph *g, unsigned int x)
+const struct font_glyph * cache_insert(const struct font_glyph *g, unsigned int x)
 {
 	struct font_glyph *spot = NULL;
 

text_rendering/cache.h

@@ -7,7 +7,7 @@ void cache_init(void);
 void cache_destroy(void);
 const struct font_glyph * cache_search(unsigned int code);
 unsigned int cache_get(void);
-const struct font_glyph * cache_insert(struct font_glyph *g, unsigned int idx);
+const struct font_glyph * cache_insert(const struct font_glyph *g, unsigned int idx);
 
 
 #endif

text_rendering/font.c

@@ -2,6 +2,7 @@
 #define STB_TRUETYPE_IMPLEMENTATION
 #define STBTT_STATIC
 #define MSDF_IMPLEMENTATION
+#define STB_IMAGE_WRITE_IMPLEMENTATION
 
 #include <grapheme.h>
 #include <assert.h>
@@ -9,6 +10,7 @@
 #include "font.h"
 #include "msdf_c/stb_truetype.h"
 #include "msdf_c/msdf.h"
+#include "stb_image_write.h"
 #include "util.h"
 #include "cache.h"
 
@@ -49,28 +51,39 @@ static inline void * _emalloc(size_t x, void *_) { (void)_; return emalloc(x); }
 static inline void _efree(void *x, void *_) { (void)_; efree(x); }
 
 
+struct font_atlas * font_init(void)
+{
+	return emalloc(sizeof(struct font_atlas));
+}
+
+
 // loads a font into memory, storing all the ASCII characters in the atlas
-int font_load(struct font_atlas *atlas, const char *path, int height)
+int font_load(struct font_atlas *atlas, const char *path)
 {
 	if (!atlas || !path)
 		return -1;
 
+	int err;
+
 	dump_file(path, &(atlas->file), &(atlas->file_size));
 
-	stbtt_InitFont(&(atlas->priv.stb), atlas->file, 0);
-	atlas->priv.scale = stbtt_ScaleForPixelHeight(&(atlas->priv.stb), height);
-	int ascent, descent, linegap, baseline;
-	int x0,y0,x1,y1;
-	stbtt_GetFontVMetrics(&(atlas->priv.stb), &ascent, &descent, &linegap);
-	stbtt_GetFontBoundingBox(&(atlas->priv.stb), &x0, &y0, &x1, &y1);
+	err = stbtt_InitFont(&(atlas->priv.stb), atlas->file, 0);
+	ERROR(err == 0, -1);
 
-	baseline = atlas->priv.scale * -y0;
+	atlas->priv.scale = stbtt_ScaleForPixelHeight(&(atlas->priv.stb), glyph_h);
+	//int ascent, descent, linegap, baseline;
+	//int x0,y0,x1,y1;
+	//stbtt_GetFontVMetrics(&(atlas->priv.stb), &ascent, &descent, &linegap);
+	//stbtt_GetFontBoundingBox(&(atlas->priv.stb), &x0, &y0, &x1, &y1);
+	//baseline = atlas->priv.scale * -y0;
 	//atlas->glyph_max_w = (atlas->priv.scale*x1) - (atlas->priv.scale*x0);
 	//atlas->glyph_max_h = (baseline+atlas->priv.scale*y1) - (baseline+atlas->priv.scale*y0);
 	//atlas->atlas = emalloc(atlas->glyph_max_w*atlas->glyph_max_h*CACHE_SIZE);
+
 	atlas->atlas  = ecalloc(CACHE_SIZE, BDEPTH*glyph_h*glyph_w);
-	atlas->width  = glyph_w*CACHE_SIZE;
-	atlas->height = glyph_h*CACHE_SIZE;
+	memset(atlas->atlas, 0, CACHE_SIZE*BDEPTH*glyph_h*glyph_w);
+	atlas->width  = glyph_w*CACHE_SIZE/2;
+	atlas->height = glyph_h*CACHE_SIZE/2;
 
 	atlas->priv.ctx = (msdf_AllocCtx){_emalloc, _efree, NULL};
 
@@ -84,36 +97,60 @@ int font_free(struct font_atlas *atlas)
 {
 	efree(atlas->atlas);
 	efree(atlas->file);
+	efree(atlas);
+	cache_destroy();
 	return 0;
 }
 
 
 // FIXME: when generating the sdf I only use the height, so to not encounter memory
 //        errors height and width must be equal
-static unsigned int insert(struct font_atlas *atlas)
+const struct font_glyph * font_get_glyph_texture(struct font_atlas *atlas, unsigned int code)
 {
-	unsigned char *a = atlas->atlas;
-	msdf_Result  res = atlas->priv.msdf;
+	const struct font_glyph *r;
+	if ((r = cache_search(code)) != NULL)
+		return r;
+
+	// generate the sdf and put it into the cache
+	// TODO: generate the whole block at once
+	int idx = stbtt_FindGlyphIndex(&atlas->priv.stb, code);
+	// FIXME: what happens if I change the range?
+	int err;
+	err = msdf_genGlyph(&atlas->priv.msdf,
+		&atlas->priv.stb,
+		idx,
+		BORDER,
+		atlas->priv.scale,
+		2.0f/glyph_h,
+		&atlas->priv.ctx);
+	if (!err)
+		return NULL;
 
+
+	unsigned int spot = cache_get();
+	unsigned int oy   = (glyph_h * spot) / atlas->width;
+	unsigned int ox   = (glyph_h * spot) % atlas->height;
+	unsigned int w    = atlas->width; 
+
+	// sum magic shit
+	struct {unsigned char r,g,b;} *a = (void *)atlas->atlas;
+	msdf_Result  *res = &atlas->priv.msdf;
 	float s  = glyph_h;
 	float tw = ((s * 0.7f) + s) / (s * 2.0f);
 	float ta = tw - 0.5f;
 	float ts = 0.5 - ta / 2;
 	float te = ts + ta;
 
-	unsigned int spot = cache_get();
-	unsigned int off = spot * glyph_h * glyph_w * BDEPTH;
-
 	#define NORMALIZE(x) x = x > ts ? (x > te ? 1.0f : (x-ts)/ta+0.0f) : (0.0f)
 
-	for (int y = 0; y < res.height; y++) {
-	        int yPos = res.width * 3 * y;
-		for (int x = 0; x < res.width; x++) {
+	for (int y = 0; y < res->height; y++) {
+	        int yPos = res->width * 3 * y;
+		for (int x = 0; x < res->width; x++) {
 
 			int i = yPos + (x * 3);
-			float r = res.rgb[i+0];
-			float g = res.rgb[i+1];
-			float b = res.rgb[i+2];
+			float r = res->rgb[i+0];
+			float g = res->rgb[i+1];
+			float b = res->rgb[i+2];
 
 			r = (r + s) / (s * 2.0f);
 			g = (g + s) / (s * 2.0f);
@@ -123,36 +160,31 @@ static unsigned int insert(struct font_atlas *atlas)
 			NORMALIZE(g);
 			NORMALIZE(b);
 
-			a[off + glyph_w*y + x + 0] = r * 255.0f; // (r > 0.5f) ? 255.0f : r * 255.0f;
-			a[off + glyph_w*y + x + 0] = g * 255.0f; // (g > 0.5f) ? 255.0f : g * 255.0f;
-			a[off + glyph_w*y + x + 0] = b * 255.0f; // (b > 0.5f) ? 255.0f : b * 255.0f;
+			a[(oy+y)*w + (ox+x)].r = r * 255.0f; // (r > 0.5f) ? 255.0f : r * 255.0f;
+			a[(oy+y)*w + (ox+x)].g = g * 255.0f; // (g > 0.5f) ? 255.0f : g * 255.0f;
+			a[(oy+y)*w + (ox+x)].b = b * 255.0f; // (b > 0.5f) ? 255.0f : b * 255.0f;
 		}
 	}
 
-	return spot;
+	struct font_glyph g = {
+		.codepoint = code,
+		.u = ox,
+		.v = oy,
+		.w = res->width,
+		.h = res->height,
+	};
+	return cache_insert(&g, spot);
 }
 
 
-struct font_glyph * font_get_glyph_texture(struct font_atlas *atlas, unsigned int code)
+void font_dump(const struct font_atlas *atlas, const char *path)
 {
-	struct font_glyph *r;
-	if ((r = cache_search(code)) != NULL)
-		return r;
-
-	// generate the sdf and put it into the cache
-	// TODO: generate the whole block at once
-	int idx = stbtt_FindGlyphIndex(&atlas->priv.stb, code);
-	// FIXME: what happens if I change the range?
-	int s;
-	s = msdf_genGlyph(&atlas->priv.msdf,
-		&atlas->priv.stb,
-		idx,
-		BORDER,
-		atlas->priv.scale,
-		2.0f/glyph_h,
-		&atlas->priv.ctx);
-	if (!s)
-		return NULL;
-	unsigned int spot = insert(atlas);
-
+	stbi_write_png(
+		path, 
+		//atlas->width,
+		//atlas->height,
+		128, 128,
+		BDEPTH,
+		atlas->atlas,
+		BDEPTH*atlas->width);
 }

text_rendering/font.h

@@ -27,7 +27,10 @@ struct font_glyph {
 
 struct font_atlas;
 
-int font_load(struct font_atlas *atlas, const char *path, int height);
+struct font_atlas * font_init(void);
+int font_load(struct font_atlas *atlas, const char *path);
 int font_free(struct font_atlas *atlas);
+const struct font_glyph * font_get_glyph_texture(struct font_atlas *atlas, unsigned int code);
+void font_dump(const struct font_atlas *atlas, const char *path);
 
 #endif

text_rendering/main.c

@@ -4,32 +4,30 @@
 
 #include "cache.h"
 #include "font.h"
+#include "util.h"
 
 
 int main(void)
 {
-	cache_init();
+	int err;
+	struct font_atlas *at = font_init();
+	err = font_load(at, "./monospace.ttf");
+	ERROR(err, -1, printf("failed to load font\n"));
 
-	struct font_glyph *g, b;
-	b.codepoint = 'a';
-	b.u = b.v = 10;
-	b.w = b.h = 20;
-
-	g = cache_get('a');
-	if (!g)	printf("no element\n");
-	g = cache_get(0xa3c0);
-	if (!g) printf("not present\n");
-
-	const char *s = "κόσμε ciao mamma @à``²`²aas³³²";
+	const char *s = "ciao mamma";
+	const struct font_glyph *g;
 	size_t ret, off;
 	uint_least32_t cp;
 	for (off = 0; (ret = grapheme_decode_utf8(s+off, SIZE_MAX, &cp)) > 0 && cp != 0; off += ret) {
 		printf("%.*s (%d) -> %d\n", (int)ret, s+off, (int)ret, cp);
-		b.codepoint = cp;
-		if (cache_insert(&b)) printf("failed insert %d\n", b.codepoint);
-		if ((g = cache_get(cp))) printf("got %d\n", g->codepoint);
+		g = font_get_glyph_texture(at, cp);
+		if (!g)
+			printf("g is NULL\n");
 	}
 
-	cache_destroy();
+	font_dump(at, "./atlas.png");
+
+	font_free(at);
+
 	return 0;
 }

text_rendering/util.c

@@ -83,10 +83,13 @@ void dump_file(const char *path, unsigned char **buf, int *buf_len)
 	if (!fp)
 		err(EXIT_FAILURE, "Cannot open file %s", path);
 	*buf_len = lseek(fileno(fp), 0, SEEK_END);
+	rewind(fp);
 	if (*buf_len == (off_t)-1)
 		err(EXIT_FAILURE, "lseek() failed");
 	*buf = emalloc(*buf_len);
-	*buf_len = fread(*buf, 1, *buf_len, fp);
+	int ret = fread(*buf, 1, *buf_len, fp);
+	if (ret != *buf_len)
+		err(EXIT_FAILURE, "fread() returned short %s", ferror(fp) ? "stream error" : feof(fp) ? "EOF reached" : "unknown error");
 	if (fclose(fp))
 		err(EXIT_FAILURE, "Error closing file");
 }

text_rendering/util.h

@@ -1,6 +1,10 @@
 #ifndef _UTIL_H
 #define _UTIL_H
 
+
+#define ERROR(expr, ret, ...) if (expr) { __VA_ARGS__; return ret; }
+
+
 void * emalloc(unsigned long int size);
 void * ecalloc(unsigned long int nmemb, unsigned long int size);
 void efree(void *ptr);