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stb_truetype: split stbtt_PackFontRanges() into 3 functions for advanced uses, allow stbtt_PackBegin() to take NULL pixels

pull/72/head
ocornut 2015-01-18 15:24:33 +00:00
parent 80d5c4be48
commit 90c18fd41a
1 changed files with 78 additions and 48 deletions
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126
stb_truetype.h
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@ -91,7 +91,7 @@
// #include "stb_rect_pack.h" -- optional, but you really want it
// stbtt_PackBegin()
// stbtt_PackSetOversample() -- for improved quality on small fonts
// stbtt_PackFontRanges()
// stbtt_PackFontRanges() -- pack and renders
// stbtt_PackEnd()
// stbtt_GetPackedQuad()
//
@ -493,6 +493,7 @@ typedef struct
} stbtt_packedchar;
typedef struct stbtt_pack_context stbtt_pack_context;
typedef struct stbtt_fontinfo stbtt_fontinfo;
extern int stbtt_PackBegin(stbtt_pack_context *spc, unsigned char *pixels, int width, int height, int stride_in_bytes, int padding, void *alloc_context);
// Initializes a packing context stored in the passed-in stbtt_pack_context.
@ -538,6 +539,12 @@ extern int stbtt_PackFontRanges(stbtt_pack_context *spc, unsigned char *fontdat
// ranges. This will usually create a better-packed bitmap than multiple
// calls to stbtt_PackFontRange.
extern int stbtt_PackFontRangesGatherRects(stbtt_pack_context *spc, stbtt_fontinfo *info, stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects);
extern int stbtt_PackFontRangesRenderIntoRects(stbtt_pack_context *spc, stbtt_fontinfo *info, stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects);
// Those functions are called by stbtt_PackFontRanges(). If you want to
// pack multiple fonts or custom data into a same texture, you may copy
// the contents of stbtt_PackFontRanges() and create a custom version
// using those functions.
extern void stbtt_PackSetOversampling(stbtt_pack_context *spc, unsigned int h_oversample, unsigned int v_oversample);
// Oversampling a font increases the quality by allowing higher-quality subpixel
@ -2158,7 +2165,8 @@ int stbtt_PackBegin(stbtt_pack_context *spc, unsigned char *pixels, int pw, int
stbrp_init_target(context, pw-padding, ph-padding, nodes, num_nodes);
STBTT_memset(pixels, 0, pw*ph); // background of 0 around pixels
if (pixels)
STBTT_memset(pixels, 0, pw*ph); // background of 0 around pixels
return 1;
}
@ -2301,63 +2309,51 @@ static float stbtt__oversample_shift(int oversample)
return (float)-(oversample - 1) / (2.0f * (float)oversample);
}
int stbtt_PackFontRanges(stbtt_pack_context *spc, unsigned char *fontdata, int font_index, stbtt_pack_range *ranges, int num_ranges)
// rects array must be big enough to accommodate all characters in the given ranges
int stbtt_PackFontRangesGatherRects(stbtt_pack_context *spc, stbtt_fontinfo *info, stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects)
{
int i,j,k;
k=0;
for (i=0; i < num_ranges; ++i) {
float fh = ranges[i].font_size;
float scale = fh > 0 ? stbtt_ScaleForPixelHeight(info, fh) : stbtt_ScaleForMappingEmToPixels(info, -fh);
for (j=0; j < ranges[i].num_chars_in_range; ++j) {
int x0,y0,x1,y1;
int glyph = stbtt_FindGlyphIndex(info,ranges[i].first_unicode_char_in_range + j);
stbtt_GetGlyphBitmapBoxSubpixel(info,glyph,
scale * spc->h_oversample,
scale * spc->v_oversample,
0,0,
&x0,&y0,&x1,&y1);
rects[k].w = (stbrp_coord) (x1-x0 + spc->padding + spc->h_oversample-1);
rects[k].h = (stbrp_coord) (y1-y0 + spc->padding + spc->v_oversample-1);
++k;
}
}
return k;
}
// rects array must be big enough to accommodate all characters in the given ranges
int stbtt_PackFontRangesRenderIntoRects(stbtt_pack_context *spc, stbtt_fontinfo *info, stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects)
{
stbtt_fontinfo info;
float recip_h = 1.0f / spc->h_oversample;
float recip_v = 1.0f / spc->v_oversample;
float sub_x = stbtt__oversample_shift(spc->h_oversample);
float sub_y = stbtt__oversample_shift(spc->v_oversample);
int i,j,k,n, return_value = 1;
stbrp_context *context = (stbrp_context *) spc->pack_info;
stbrp_rect *rects;
// flag all characters as NOT packed
for (i=0; i < num_ranges; ++i)
for (j=0; j < ranges[i].num_chars_in_range; ++j)
ranges[i].chardata_for_range[j].x0 =
ranges[i].chardata_for_range[j].y0 =
ranges[i].chardata_for_range[j].x1 =
ranges[i].chardata_for_range[j].y1 = 0;
n = 0;
for (i=0; i < num_ranges; ++i)
n += ranges[i].num_chars_in_range;
rects = (stbrp_rect *) STBTT_malloc(sizeof(*rects) * n, spc->user_allocator_context);
if (rects == NULL)
return 0;
stbtt_InitFont(&info, fontdata, stbtt_GetFontOffsetForIndex(fontdata,font_index));
k=0;
for (i=0; i < num_ranges; ++i) {
float fh = ranges[i].font_size;
float scale = fh > 0 ? stbtt_ScaleForPixelHeight(&info, fh) : stbtt_ScaleForMappingEmToPixels(&info, -fh);
for (j=0; j < ranges[i].num_chars_in_range; ++j) {
int x0,y0,x1,y1;
stbtt_GetCodepointBitmapBoxSubpixel(&info, ranges[i].first_unicode_char_in_range + j,
scale * spc->h_oversample,
scale * spc->v_oversample,
0,0,
&x0,&y0,&x1,&y1);
rects[k].w = (stbrp_coord) (x1-x0 + spc->padding + spc->h_oversample-1);
rects[k].h = (stbrp_coord) (y1-y0 + spc->padding + spc->v_oversample-1);
++k;
}
}
stbrp_pack_rects(context, rects, k);
int i,j,k, return_value = 1;
k = 0;
for (i=0; i < num_ranges; ++i) {
float fh = ranges[i].font_size;
float scale = fh > 0 ? stbtt_ScaleForPixelHeight(&info, fh) : stbtt_ScaleForMappingEmToPixels(&info, -fh);
float scale = fh > 0 ? stbtt_ScaleForPixelHeight(info, fh) : stbtt_ScaleForMappingEmToPixels(info, -fh);
for (j=0; j < ranges[i].num_chars_in_range; ++j) {
stbrp_rect *r = &rects[k];
if (r->was_packed) {
stbtt_packedchar *bc = &ranges[i].chardata_for_range[j];
int advance, lsb, x0,y0,x1,y1;
int glyph = stbtt_FindGlyphIndex(&info, ranges[i].first_unicode_char_in_range + j);
int glyph = stbtt_FindGlyphIndex(info, ranges[i].first_unicode_char_in_range + j);
stbrp_coord pad = (stbrp_coord) spc->padding;
// pad on left and top
@ -2365,12 +2361,12 @@ int stbtt_PackFontRanges(stbtt_pack_context *spc, unsigned char *fontdata, int f
r->y += pad;
r->w -= pad;
r->h -= pad;
stbtt_GetGlyphHMetrics(&info, glyph, &advance, &lsb);
stbtt_GetGlyphBitmapBox(&info, glyph,
stbtt_GetGlyphHMetrics(info, glyph, &advance, &lsb);
stbtt_GetGlyphBitmapBox(info, glyph,
scale * spc->h_oversample,
scale * spc->v_oversample,
&x0,&y0,&x1,&y1);
stbtt_MakeGlyphBitmapSubpixel(&info,
stbtt_MakeGlyphBitmapSubpixel(info,
spc->pixels + r->x + r->y*spc->stride_in_bytes,
r->w - spc->h_oversample+1,
r->h - spc->v_oversample+1,
@ -2410,6 +2406,40 @@ int stbtt_PackFontRanges(stbtt_pack_context *spc, unsigned char *fontdata, int f
return return_value;
}
int stbtt_PackFontRanges(stbtt_pack_context *spc, unsigned char *fontdata, int font_index, stbtt_pack_range *ranges, int num_ranges)
{
stbtt_fontinfo info;
int i,j,n, return_value = 1;
stbrp_context *context = (stbrp_context *) spc->pack_info;
stbrp_rect *rects;
// flag all characters as NOT packed
for (i=0; i < num_ranges; ++i)
for (j=0; j < ranges[i].num_chars_in_range; ++j)
ranges[i].chardata_for_range[j].x0 =
ranges[i].chardata_for_range[j].y0 =
ranges[i].chardata_for_range[j].x1 =
ranges[i].chardata_for_range[j].y1 = 0;
n = 0;
for (i=0; i < num_ranges; ++i)
n += ranges[i].num_chars_in_range;
rects = (stbrp_rect *) STBTT_malloc(sizeof(*rects) * n, spc->user_allocator_context);
if (rects == NULL)
return 0;
stbtt_InitFont(&info, fontdata, stbtt_GetFontOffsetForIndex(fontdata,font_index));
n = stbtt_PackFontRangesGatherRects(spc, &info, ranges, num_ranges, rects);
stbrp_pack_rects(context, rects, n);
return_value = stbtt_PackFontRangesRenderIntoRects(spc, &info, ranges, num_ranges, rects);
return return_value;
}
int stbtt_PackFontRange(stbtt_pack_context *spc, unsigned char *fontdata, int font_index, float font_size,
int first_unicode_char_in_range, int num_chars_in_range, stbtt_packedchar *chardata_for_range)
{