michael@0: 
michael@0: /*
michael@0:  * Copyright 2006 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #include "SkBitmap.h"
michael@0: #include "SkMask.h"
michael@0: 
michael@0: #ifndef ClearLow3Bits_DEFINED
michael@0: #define ClearLow3Bits_DEFINED
michael@0:     #define ClearLow3Bits(x)    ((unsigned)(x) >> 3 << 3)
michael@0: #endif
michael@0: 
michael@0: /*
michael@0:     SK_BLITBWMASK_NAME          name of function(const SkBitmap& bitmap, const SkMask& mask, const SkIRect& clip, SK_BLITBWMASK_ARGS)
michael@0:     SK_BLITBWMASK_ARGS          list of additional arguments to SK_BLITBWMASK_NAME, beginning with a comma
michael@0:     SK_BLITBWMASK_BLIT8         name of function(U8CPU byteMask, SK_BLITBWMASK_DEVTYPE* dst, int x, int y)
michael@0:     SK_BLITBWMASK_GETADDR       either getAddr32 or getAddr16 or getAddr8
michael@0:     SK_BLITBWMASK_DEVTYPE       either U32 or U16 or U8
michael@0: */
michael@0: 
michael@0: static void SK_BLITBWMASK_NAME(const SkBitmap& bitmap, const SkMask& srcMask, const SkIRect& clip SK_BLITBWMASK_ARGS)
michael@0: {
michael@0:     SkASSERT(clip.fRight <= srcMask.fBounds.fRight);
michael@0: 
michael@0:     int cx = clip.fLeft;
michael@0:     int cy = clip.fTop;
michael@0:     int maskLeft = srcMask.fBounds.fLeft;
michael@0:     unsigned mask_rowBytes = srcMask.fRowBytes;
michael@0:     size_t bitmap_rowBytes = bitmap.rowBytes();
michael@0:     unsigned height = clip.height();
michael@0: 
michael@0:     SkASSERT(mask_rowBytes != 0);
michael@0:     SkASSERT(bitmap_rowBytes != 0);
michael@0:     SkASSERT(height != 0);
michael@0: 
michael@0:     const uint8_t* bits = srcMask.getAddr1(cx, cy);
michael@0:     SK_BLITBWMASK_DEVTYPE* device = bitmap.SK_BLITBWMASK_GETADDR(cx, cy);
michael@0: 
michael@0:     if (cx == maskLeft && clip.fRight == srcMask.fBounds.fRight)
michael@0:     {
michael@0:         do {
michael@0:             SK_BLITBWMASK_DEVTYPE* dst = device;
michael@0:             unsigned rb = mask_rowBytes;
michael@0:             do {
michael@0:                 U8CPU mask = *bits++;
michael@0:                 SK_BLITBWMASK_BLIT8(mask, dst);
michael@0:                 dst += 8;
michael@0:             } while (--rb != 0);
michael@0:             device = (SK_BLITBWMASK_DEVTYPE*)((char*)device + bitmap_rowBytes);
michael@0:         } while (--height != 0);
michael@0:     }
michael@0:     else
michael@0:     {
michael@0:         int left_edge = cx - maskLeft;
michael@0:         SkASSERT(left_edge >= 0);
michael@0:         int rite_edge = clip.fRight - maskLeft;
michael@0:         SkASSERT(rite_edge > left_edge);
michael@0: 
michael@0:         int left_mask = 0xFF >> (left_edge & 7);
michael@0:         int rite_mask = 0xFF << (8 - (rite_edge & 7));
michael@0:         rite_mask &= 0xFF;  // only want low-8 bits of mask
michael@0:         int full_runs = (rite_edge >> 3) - ((left_edge + 7) >> 3);
michael@0: 
michael@0:         // check for empty right mask, so we don't read off the end (or go slower than we need to)
michael@0:         if (rite_mask == 0)
michael@0:         {
michael@0:             SkASSERT(full_runs >= 0);
michael@0:             full_runs -= 1;
michael@0:             rite_mask = 0xFF;
michael@0:         }
michael@0:         if (left_mask == 0xFF)
michael@0:             full_runs -= 1;
michael@0: 
michael@0:         // back up manually so we can keep in sync with our byte-aligned src
michael@0:         // and not trigger an assert from the getAddr## function
michael@0:         device -= left_edge & 7;
michael@0: 
michael@0:         if (full_runs < 0)
michael@0:         {
michael@0:             left_mask &= rite_mask;
michael@0:             SkASSERT(left_mask != 0);
michael@0:             do {
michael@0:                 U8CPU mask = *bits & left_mask;
michael@0:                 SK_BLITBWMASK_BLIT8(mask, device);
michael@0:                 bits += mask_rowBytes;
michael@0:                 device = (SK_BLITBWMASK_DEVTYPE*)((char*)device + bitmap_rowBytes);
michael@0:             } while (--height != 0);
michael@0:         }
michael@0:         else
michael@0:         {
michael@0:             do {
michael@0:                 int runs = full_runs;
michael@0:                 SK_BLITBWMASK_DEVTYPE* dst = device;
michael@0:                 const uint8_t* b = bits;
michael@0:                 U8CPU   mask;
michael@0: 
michael@0:                 mask = *b++ & left_mask;
michael@0:                 SK_BLITBWMASK_BLIT8(mask, dst);
michael@0:                 dst += 8;
michael@0: 
michael@0:                 while (--runs >= 0)
michael@0:                 {
michael@0:                     mask = *b++;
michael@0:                     SK_BLITBWMASK_BLIT8(mask, dst);
michael@0:                     dst += 8;
michael@0:                 }
michael@0: 
michael@0:                 mask = *b & rite_mask;
michael@0:                 SK_BLITBWMASK_BLIT8(mask, dst);
michael@0: 
michael@0:                 bits += mask_rowBytes;
michael@0:                 device = (SK_BLITBWMASK_DEVTYPE*)((char*)device + bitmap_rowBytes);
michael@0:             } while (--height != 0);
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: #undef SK_BLITBWMASK_NAME
michael@0: #undef SK_BLITBWMASK_ARGS
michael@0: #undef SK_BLITBWMASK_BLIT8
michael@0: #undef SK_BLITBWMASK_GETADDR
michael@0: #undef SK_BLITBWMASK_DEVTYPE
michael@0: #undef SK_BLITBWMASK_DOROWSETUP