SDL_ttf-2.0.10 源代码

/* SDL_ttf: A companion library to SDL for working with TrueType (tm) fonts Copyright (C) 1997-2009 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga [email protected] */ /* $Id: SDL_ttf.c 5141 2009-10-18 20:47:04Z slouken $ */ #include <math.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #ifdef HAVE_ALLOCA_H #include <alloca.h> #endif #ifdef HAVE_ALLOCA #define ALLOCA(n) ((void*)alloca(n)) #define FREEA(p) #else #define ALLOCA(n) malloc(n) #define FREEA(p) free(p) #endif #include <ft2build.h> #include FT_FREETYPE_H #include FT_OUTLINE_H #include FT_STROKER_H #include FT_GLYPH_H #include FT_TRUETYPE_IDS_H #include "SDL.h" #include "SDL_endian.h" #include "SDL_ttf.h" /* FIXME: Right now we assume the gray-scale renderer Freetype is using supports 256 shades of gray, but we should instead key off of num_grays in the result FT_Bitmap after the FT_Render_Glyph() call. */ #define NUM_GRAYS 256 /* Handy routines for converting from fixed point */ #define FT_FLOOR(X) ((X & -64) / 64) #define FT_CEIL(X) (((X + 63) & -64) / 64) #define CACHED_METRICS 0x10 #define CACHED_BITMAP 0x01 #define CACHED_PIXMAP 0x02 /* Cached glyph information */ typedef struct cached_glyph { int stored; FT_UInt index; FT_Bitmap bitmap; FT_Bitmap pixmap; int minx; int maxx; int miny; int maxy; int yoffset; int advance; Uint16 cached; } c_glyph; /* The structure used to hold internal font information */ struct _TTF_Font { /* Freetype2 maintains all sorts of useful info itself */ FT_Face face; /* We'll cache these ourselves */ int height; int ascent; int descent; int lineskip; /* The font style */ int face_style; int style; int outline; /* Whether kerning is desired */ int kerning; /* Extra width in glyph bounds for text styles */ int glyph_overhang; float glyph_italics; /* Information in the font for underlining */ int underline_offset; int underline_height; /* Cache for style-transformed glyphs */ c_glyph *current; c_glyph cache[256]; c_glyph scratch; /* We are responsible for closing the font stream */ SDL_RWops *src; int freesrc; FT_Open_Args args; /* For non-scalable formats, we must remember which font index size */ int font_size_family; /* really just flags passed into FT_Load_Glyph */ int hinting; }; /* Handle a style only if the font does not already handle it */ #define TTF_HANDLE_STYLE_BOLD(font) (((font)->style & TTF_STYLE_BOLD) && \ !((font)->face_style & TTF_STYLE_BOLD)) #define TTF_HANDLE_STYLE_ITALIC(font) (((font)->style & TTF_STYLE_ITALIC) && \ !((font)->face_style & TTF_STYLE_ITALIC)) #define TTF_HANDLE_STYLE_UNDERLINE(font) ((font)->style & TTF_STYLE_UNDERLINE) #define TTF_HANDLE_STYLE_STRIKETHROUGH(font) ((font)->style & TTF_STYLE_STRIKETHROUGH) /* Font styles that does not impact glyph drawing */ #define TTF_STYLE_NO_GLYPH_CHANGE (TTF_STYLE_UNDERLINE | TTF_STYLE_STRIKETHROUGH) /* The FreeType font engine/library */ static FT_Library library; static int TTF_initialized = 0; static int TTF_byteswapped = 0; /* UNICODE string utilities */ static __inline__ int UNICODE_strlen(const Uint16 *text) { int size = 0; while ( *text++ ) { ++size; } return size; } static __inline__ void UNICODE_strcpy(Uint16 *dst, const Uint16 *src, int swap) { if ( swap ) { while ( *src ) { *dst = SDL_Swap16(*src); ++src; ++dst; } *dst = '\0'; } else { while ( *src ) { *dst = *src; ++src; ++dst; } *dst = '\0'; } } /* Gets the top row of the underline. The outline is taken into account. */ static __inline__ int TTF_underline_top_row(TTF_Font *font) { /* With outline, the underline_offset is underline_offset+outline. */ /* So, we don't have to remove the top part of the outline height. */ return font->ascent - font->underline_offset - 1; } /* Gets the bottom row of the underline. The outline is taken into account. */ static __inline__ int TTF_underline_bottom_row(TTF_Font *font) { int row = TTF_underline_top_row(font) + font->underline_height; if( font->outline > 0 ) { /* Add underline_offset outline offset and */ /* the bottom part of the outline. */ row += font->outline * 2; } return row; } /* Gets the top row of the strikethrough. The outline is taken into account. */ static __inline__ int TTF_strikethrough_top_row(TTF_Font *font) { /* With outline, the first text row is 'outline'. */ /* So, we don't have to remove the top part of the outline height. */ return font->height / 2; } /* Gets the bottom row of the strikethrough. The outline is taken into account. */ static __inline__ int TTF_strikethrough_bottom_row(TTF_Font *font) { int row = TTF_strikethrough_top_row(font) + font->underline_height; if( font->outline > 0 ) { /* Add first text row outline offset and */ /* the bottom part of the outline. */ row += font->outline * 2; } return row; } static void TTF_initLineMectrics(const TTF_Font *font, const SDL_Surface *textbuf, const int row, Uint8 **pdst, int *pheight) { Uint8 *dst; int height; dst = (Uint8 *)textbuf->pixels; if( row > 0 ) { dst += row * textbuf->pitch; } height = font->underline_height; /* Take outline into account */ if( font->outline > 0 ) { height += font->outline * 2; } *pdst = dst; *pheight = height; } /* Draw a solid line of underline_height (+ optional outline) at the given row. The row value must take the outline into account. */ static void TTF_drawLine_Solid(const TTF_Font *font, const SDL_Surface *textbuf, const int row) { int line; Uint8 *dst_check = (Uint8*)textbuf->pixels + textbuf->pitch * textbuf->h; Uint8 *dst; int height; TTF_initLineMectrics(font, textbuf, row, &dst, &height); /* Draw line */ for ( line=height; line>0 && dst < dst_check; --line ) { /* 1 because 0 is the bg color */ memset( dst, 1, textbuf->w ); dst += textbuf->pitch; } } /* Draw a shaded line of underline_height (+ optional outline) at the given row. The row value must take the outline into account. */ static void TTF_drawLine_Shaded(const TTF_Font *font, const SDL_Surface *textbuf, const int row) { int line; Uint8 *dst_check = (Uint8*)textbuf->pixels + textbuf->pitch * textbuf->h; Uint8 *dst; int height; TTF_initLineMectrics(font, textbuf, row, &dst, &height); /* Draw line */ for ( line=height; line>0 && dst < dst_check; --line ) { memset( dst, NUM_GRAYS - 1, textbuf->w ); dst += textbuf->pitch; } } /* Draw a blended line of underline_height (+ optional outline) at the given row. The row value must take the outline into account. */ static void TTF_drawLine_Blended(const TTF_Font *font, const SDL_Surface *textbuf, const int row, const Uint32 color) { int line; Uint32 *dst_check = (Uint32*)textbuf->pixels + textbuf->pitch/4 * textbuf->h; Uint8 *dst8; /* destination, byte version */ Uint32 *dst; int height; int col; Uint32 pixel = color | 0xFF000000; /* Amask */ TTF_initLineMectrics(font, textbuf, row, &dst8, &height); dst = (Uint32 *) dst8; /* Draw line */ for ( line=height; line>0 && dst < dst_check; --line ) { for ( col=0; col < textbuf->w; ++col ) { dst[col] = pixel; } dst += textbuf->pitch/4; } } /* rcg06192001 get linked library's ve