reed@google.com | 72e7808 | 2013-11-25 20:54:56 +0000 | [diff] [blame^] | 1 | |
| 2 | /* |
| 3 | * Copyright 2006 The Android Open Source Project |
| 4 | * |
| 5 | * Use of this source code is governed by a BSD-style license that can be |
| 6 | * found in the LICENSE file. |
| 7 | */ |
| 8 | |
| 9 | |
| 10 | #include "SkCoreBlitters.h" |
| 11 | |
| 12 | SkA1_Blitter::SkA1_Blitter(const SkBitmap& device, const SkPaint& paint) |
| 13 | : INHERITED(device) { |
| 14 | fSrcA = paint.getAlpha(); |
| 15 | } |
| 16 | |
| 17 | void SkA1_Blitter::blitH(int x, int y, int width) { |
| 18 | SkASSERT(x >= 0 && y >= 0 && |
| 19 | (unsigned)(x + width) <= (unsigned)fDevice.width()); |
| 20 | |
| 21 | if (fSrcA <= 0x7F) { |
| 22 | return; |
| 23 | } |
| 24 | uint8_t* dst = fDevice.getAddr1(x, y); |
| 25 | int right = x + width; |
| 26 | |
| 27 | int left_mask = 0xFF >> (x & 7); |
| 28 | int rite_mask = 0xFF << (8 - (right & 7)); |
| 29 | int full_runs = (right >> 3) - ((x + 7) >> 3); |
| 30 | |
| 31 | // check for empty right mask, so we don't read off the end |
| 32 | // (or go slower than we need to) |
| 33 | if (rite_mask == 0) { |
| 34 | SkASSERT(full_runs >= 0); |
| 35 | full_runs -= 1; |
| 36 | rite_mask = 0xFF; |
| 37 | } |
| 38 | if (left_mask == 0xFF) { |
| 39 | full_runs -= 1; |
| 40 | } |
| 41 | if (full_runs < 0) { |
| 42 | SkASSERT((left_mask & rite_mask) != 0); |
| 43 | *dst |= (left_mask & rite_mask); |
| 44 | } else { |
| 45 | *dst++ |= left_mask; |
| 46 | memset(dst, 0xFF, full_runs); |
| 47 | dst += full_runs; |
| 48 | *dst |= rite_mask; |
| 49 | } |
| 50 | } |