Merge pull request #431 from olliwang/font

Resets font atlas when it is full.

src/fontstash.h

@@ -38,6 +38,11 @@ enum FONSalign {
 	FONS_ALIGN_BASELINE	= 1<<6, // Default
 };
 
+enum FONSglyphBitmap {
+	FONS_GLYPH_BITMAP_OPTIONAL = 1,
+	FONS_GLYPH_BITMAP_REQUIRED = 2,
+};
+
 enum FONSerrorCode {
 	// Font atlas is full.
 	FONS_ATLAS_FULL = 1,
@@ -78,6 +83,7 @@ struct FONStextIter {
 	const char* next;
 	const char* end;
 	unsigned int utf8state;
+	int bitmapOption;
 };
 typedef struct FONStextIter FONStextIter;
 
@@ -122,7 +128,7 @@ void fonsLineBounds(FONScontext* s, float y, float* miny, float* maxy);
 void fonsVertMetrics(FONScontext* s, float* ascender, float* descender, float* lineh);
 
 // Text iterator
-int fonsTextIterInit(FONScontext* stash, FONStextIter* iter, float x, float y, const char* str, const char* end);
+int fonsTextIterInit(FONScontext* stash, FONStextIter* iter, float x, float y, const char* str, const char* end, int bitmapOption);
 int fonsTextIterNext(FONScontext* stash, FONStextIter* iter, struct FONSquad* quad);
 
 // Pull texture changes
@@ -1030,7 +1036,7 @@ static void fons__blur(FONScontext* stash, unsigned char* dst, int w, int h, int
 }
 
 static FONSglyph* fons__getGlyph(FONScontext* stash, FONSfont* font, unsigned int codepoint,
-								 short isize, short iblur)
+								 short isize, short iblur, int bitmapOption)
 {
 	int i, g, advance, lsb, x0, y0, x1, y1, gw, gh, gx, gy, x, y;
 	float scale;
@@ -1053,12 +1059,18 @@ static FONSglyph* fons__getGlyph(FONScontext* stash, FONSfont* font, unsigned in
 	h = fons__hashint(codepoint) & (FONS_HASH_LUT_SIZE-1);
 	i = font->lut[h];
 	while (i != -1) {
-		if (font->glyphs[i].codepoint == codepoint && font->glyphs[i].size == isize && font->glyphs[i].blur == iblur)
-			return &font->glyphs[i];
+		if (font->glyphs[i].codepoint == codepoint && font->glyphs[i].size == isize && font->glyphs[i].blur == iblur) {
+			glyph = &font->glyphs[i];
+			if (bitmapOption == FONS_GLYPH_BITMAP_OPTIONAL || (glyph->x0 >= 0 && glyph->y0 >= 0)) {
+			  return glyph;
+			}
+			// At this point, glyph exists but the bitmap data is not yet created.
+			break;
+		}
 		i = font->glyphs[i].next;
 	}
 
-	// Could not find glyph, create it.
+	// Create a new glyph or rasterize bitmap data for a cached glyph.
 	g = fons__tt_getGlyphIndex(&font->font, codepoint);
 	// Try to find the glyph in fallback fonts.
 	if (g == 0) {
@@ -1079,20 +1091,34 @@ static FONSglyph* fons__getGlyph(FONScontext* stash, FONSfont* font, unsigned in
 	gw = x1-x0 + pad*2;
 	gh = y1-y0 + pad*2;
 
-	// Find free spot for the rect in the atlas
-	added = fons__atlasAddRect(stash->atlas, gw, gh, &gx, &gy);
-	if (added == 0 && stash->handleError != NULL) {
-		// Atlas is full, let the user to resize the atlas (or not), and try again.
-		stash->handleError(stash->errorUptr, FONS_ATLAS_FULL, 0);
+	// Determines the spot to draw glyph in the atlas.
+	if (bitmapOption == FONS_GLYPH_BITMAP_REQUIRED) {
+		// Find free spot for the rect in the atlas
 		added = fons__atlasAddRect(stash->atlas, gw, gh, &gx, &gy);
+		if (added == 0 && stash->handleError != NULL) {
+			// Atlas is full, let the user to resize the atlas (or not), and try again.
+			stash->handleError(stash->errorUptr, FONS_ATLAS_FULL, 0);
+			added = fons__atlasAddRect(stash->atlas, gw, gh, &gx, &gy);
+		}
+		if (added == 0) return NULL;
+	} else {
+		// Negative coordinate indicates there is no bitmap data created.
+		gx = -1;
+		gy = -1;
 	}
-	if (added == 0) return NULL;
 
 	// Init glyph.
-	glyph = fons__allocGlyph(font);
-	glyph->codepoint = codepoint;
-	glyph->size = isize;
-	glyph->blur = iblur;
+	if (glyph == NULL) {
+		glyph = fons__allocGlyph(font);
+		glyph->codepoint = codepoint;
+		glyph->size = isize;
+		glyph->blur = iblur;
+		glyph->next = 0;
+
+		// Insert char to hash lookup.
+		glyph->next = font->lut[h];
+		font->lut[h] = font->nglyphs-1;
+	}
 	glyph->index = g;
 	glyph->x0 = (short)gx;
 	glyph->y0 = (short)gy;
@@ -1101,15 +1127,14 @@ static FONSglyph* fons__getGlyph(FONScontext* stash, FONSfont* font, unsigned in
 	glyph->xadv = (short)(scale * advance * 10.0f);
 	glyph->xoff = (short)(x0 - pad);
 	glyph->yoff = (short)(y0 - pad);
-	glyph->next = 0;
 
-	// Insert char to hash lookup.
-	glyph->next = font->lut[h];
-	font->lut[h] = font->nglyphs-1;
+	if (bitmapOption == FONS_GLYPH_BITMAP_OPTIONAL) {
+		return glyph;
+	}
 
 	// Rasterize
 	dst = &stash->texData[(glyph->x0+pad) + (glyph->y0+pad) * stash->params.width];
-	fons__tt_renderGlyphBitmap(&renderFont->font, dst, gw-pad*2,gh-pad*2, stash->params.width, scale,scale, g);
+	fons__tt_renderGlyphBitmap(&renderFont->font, dst, gw-pad*2,gh-pad*2, stash->params.width, scale, scale, g);
 
 	// Make sure there is one pixel empty border.
 	dst = &stash->texData[glyph->x0 + glyph->y0 * stash->params.width];
@@ -1136,7 +1161,7 @@ static FONSglyph* fons__getGlyph(FONScontext* stash, FONSfont* font, unsigned in
 	if (iblur > 0) {
 		stash->nscratch = 0;
 		bdst = &stash->texData[glyph->x0 + glyph->y0 * stash->params.width];
-		fons__blur(stash, bdst, gw,gh, stash->params.width, iblur);
+		fons__blur(stash, bdst, gw, gh, stash->params.width, iblur);
 	}
 
 	stash->dirtyRect[0] = fons__mini(stash->dirtyRect[0], glyph->x0);
@@ -1298,7 +1323,7 @@ float fonsDrawText(FONScontext* stash,
 	for (; str != end; ++str) {
 		if (fons__decutf8(&utf8state, &codepoint, *(const unsigned char*)str))
 			continue;
-		glyph = fons__getGlyph(stash, font, codepoint, isize, iblur);
+		glyph = fons__getGlyph(stash, font, codepoint, isize, iblur, FONS_GLYPH_BITMAP_REQUIRED);
 		if (glyph != NULL) {
 			fons__getQuad(stash, font, prevGlyphIndex, glyph, scale, state->spacing, &x, &y, &q);
 
@@ -1321,7 +1346,7 @@ float fonsDrawText(FONScontext* stash,
 }
 
 int fonsTextIterInit(FONScontext* stash, FONStextIter* iter,
-					 float x, float y, const char* str, const char* end)
+					 float x, float y, const char* str, const char* end, int bitmapOption)
 {
 	FONSstate* state = fons__getState(stash);
 	float width;
@@ -1361,6 +1386,7 @@ int fonsTextIterInit(FONScontext* stash, FONStextIter* iter,
 	iter->end = end;
 	iter->codepoint = 0;
 	iter->prevGlyphIndex = -1;
+	iter->bitmapOption = bitmapOption;
 
 	return 1;
 }
@@ -1381,7 +1407,8 @@ int fonsTextIterNext(FONScontext* stash, FONStextIter* iter, FONSquad* quad)
 		// Get glyph and quad
 		iter->x = iter->nextx;
 		iter->y = iter->nexty;
-		glyph = fons__getGlyph(stash, iter->font, iter->codepoint, iter->isize, iter->iblur);
+		glyph = fons__getGlyph(stash, iter->font, iter->codepoint, iter->isize, iter->iblur, iter->bitmapOption);
+		// If the iterator was initialized with FONS_GLYPH_BITMAP_OPTIONAL, then the UV coordinates of the quad will be invalid.
 		if (glyph != NULL)
 			fons__getQuad(stash, iter->font, iter->prevGlyphIndex, glyph, iter->scale, iter->spacing, &iter->nextx, &iter->nexty, quad);
 		iter->prevGlyphIndex = glyph != NULL ? glyph->index : -1;
@@ -1478,7 +1505,7 @@ float fonsTextBounds(FONScontext* stash,
 	for (; str != end; ++str) {
 		if (fons__decutf8(&utf8state, &codepoint, *(const unsigned char*)str))
 			continue;
-		glyph = fons__getGlyph(stash, font, codepoint, isize, iblur);
+		glyph = fons__getGlyph(stash, font, codepoint, isize, iblur, FONS_GLYPH_BITMAP_OPTIONAL);
 		if (glyph != NULL) {
 			fons__getQuad(stash, font, prevGlyphIndex, glyph, scale, state->spacing, &x, &y, &q);
 			if (q.x0 < minx) minx = q.x0;

src/nanovg.c

@@ -2440,7 +2440,7 @@ float nvgText(NVGcontext* ctx, float x, float y, const char* string, const char*
 	verts = nvg__allocTempVerts(ctx, cverts);
 	if (verts == NULL) return x;
 
-	fonsTextIterInit(ctx->fs, &iter, x*scale, y*scale, string, end);
+	fonsTextIterInit(ctx->fs, &iter, x*scale, y*scale, string, end, FONS_GLYPH_BITMAP_REQUIRED);
 	prevIter = iter;
 	while (fonsTextIterNext(ctx->fs, &iter, &q)) {
 		float c[4*2];
@@ -2537,7 +2537,7 @@ int nvgTextGlyphPositions(NVGcontext* ctx, float x, float y, const char* string,
 	fonsSetAlign(ctx->fs, state->textAlign);
 	fonsSetFont(ctx->fs, state->fontId);
 
-	fonsTextIterInit(ctx->fs, &iter, x*scale, y*scale, string, end);
+	fonsTextIterInit(ctx->fs, &iter, x*scale, y*scale, string, end, FONS_GLYPH_BITMAP_OPTIONAL);
 	prevIter = iter;
 	while (fonsTextIterNext(ctx->fs, &iter, &q)) {
 		if (iter.prevGlyphIndex < 0 && nvg__allocTextAtlas(ctx)) { // can not retrieve glyph?
@@ -2603,7 +2603,7 @@ int nvgTextBreakLines(NVGcontext* ctx, const char* string, const char* end, floa
 
 	breakRowWidth *= scale;
 
-	fonsTextIterInit(ctx->fs, &iter, 0, 0, string, end);
+	fonsTextIterInit(ctx->fs, &iter, 0, 0, string, end, FONS_GLYPH_BITMAP_OPTIONAL);
 	prevIter = iter;
 	while (fonsTextIterNext(ctx->fs, &iter, &q)) {
 		if (iter.prevGlyphIndex < 0 && nvg__allocTextAtlas(ctx)) { // can not retrieve glyph?