ref: 80d256149b5dbef1f435df2ebb188f3572613225
dir: /sys/src/libttf/bit.c/
#include <u.h> #include <libc.h> #include <bio.h> #include <ttf.h> #include "impl.h" TTBitmap * ttfnewbitmap(int w, int h) { TTBitmap *b; b = mallocz(sizeof(TTBitmap), 1); if(b == nil) return nil; b->width = w; b->height = h; b->stride = w + 7 >> 3; b->bit = mallocz(b->stride * h, 1); if(b->bit == nil){ free(b); return nil; } return b; } void ttffreebitmap(TTBitmap *b) { if(b == nil) return; free(b->bit); free(b); } void ttfblit(TTBitmap *dst, int dx, int dy, TTBitmap *src, int sx0, int sy0, int sx1, int sy1) { uchar *sp, *dp; u32int b; int x, y, ss, ds, dx1, dy1; if(sx0 < 0) sx0 = 0; if(sy0 < 0) sy0 = 0; if(sx1 > src->width) sx1 = src->width; if(sy1 > src->height) sy1 = src->height; if(dx < 0){ sx0 -= dx; dx = 0; } if(dy < 0){ sy0 -= dy; dy = 0; } dx1 = dx + sx1 - sx0; dy1 = dy + sy1 - sy0; if(dx1 > dst->width){ sx1 -= dx1 - dst->width; dx1 = dst->width; } if(dy1 > dst->height) sy1 -= dy1 - dst->height; if(sx1 <= sx0 || sy1 <= sy0) return; ss = src->stride - ((sx1-1 >> 3) - (sx0 >> 3) + 1); ds = dst->stride - ((dx1-1 >> 3) - (dx >> 3) + 1); sp = src->bit + sy0 * src->stride + (sx0 >> 3); dp = dst->bit + dy * dst->stride + (dx >> 3); y = sy1 - sy0; do{ if(sx0 >> 3 == sx1 >> 3){ b = (*sp++ << 8 & 0xff << 8-(sx0 & 7)) & -0x10000 >> (sx1 & 7); if((sx0 & 7) == 0) b >>= 8; x = (dx & 7) + (sx1 - sx0); }else{ if((sx0 & 7) != 0) b = *sp++ << 8 & 0xff << (-sx0 & 7); else b = 0; x = (sx1 >> 3) - (sx0+7 >> 3); while(--x >= 0){ b |= *sp++; *dp++ |= b >> (dx & 7) + (-sx0 & 7); b <<= 8; } if((sx1 & 7) != 0) b |= *sp++ & -0x100 >> (sx1 & 7); x = (dx & 7) + (-sx0 & 7) + (sx1 & 7); } for(; x > 0; x -= 8){ *dp++ |= b >> (dx & 7) + (-sx0 & 7); b <<= 8; } sp += ss; dp += ds; }while(--y > 0); }