aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/core/SkBlitter_A8.cpp
blob: 92a4971e8492950fc5574e135c7d263f5f3d62a7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346

/*
 * Copyright 2006 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#include "SkCoreBlitters.h"
#include "SkColorPriv.h"
#include "SkShader.h"
#include "SkXfermode.h"

SkA8_Blitter::SkA8_Blitter(const SkBitmap& device, const SkPaint& paint)
        : INHERITED(device) {
    fSrcA = paint.getAlpha();
}

const SkBitmap* SkA8_Blitter::justAnOpaqueColor(uint32_t* value) {
    if (255 == fSrcA) {
        *value = 255;
        return &fDevice;
    }
    return NULL;
}

void SkA8_Blitter::blitH(int x, int y, int width) {
    SkASSERT(x >= 0 && y >= 0 &&
             (unsigned)(x + width) <= (unsigned)fDevice.width());

    if (fSrcA == 0) {
        return;
    }

    uint8_t* device = fDevice.getAddr8(x, y);

    if (fSrcA == 255) {
        memset(device, 0xFF, width);
    } else {
        unsigned scale = 256 - SkAlpha255To256(fSrcA);
        unsigned srcA = fSrcA;

        for (int i = 0; i < width; i++) {
            device[i] = SkToU8(srcA + SkAlphaMul(device[i], scale));
        }
    }
}

void SkA8_Blitter::blitAntiH(int x, int y, const SkAlpha antialias[],
                             const int16_t runs[]) {
    if (fSrcA == 0) {
        return;
    }

    uint8_t*    device = fDevice.getAddr8(x, y);
    unsigned    srcA = fSrcA;

    for (;;) {
        int count = runs[0];
        SkASSERT(count >= 0);
        if (count == 0) {
            return;
        }
        unsigned aa = antialias[0];

        if (aa == 255 && srcA == 255) {
            memset(device, 0xFF, count);
        } else {
            unsigned sa = SkAlphaMul(srcA, SkAlpha255To256(aa));
            unsigned scale = 256 - sa;

            for (int i = 0; i < count; i++) {
                device[i] = SkToU8(sa + SkAlphaMul(device[i], scale));
            }
        }
        runs += count;
        antialias += count;
        device += count;
    }
}

/////////////////////////////////////////////////////////////////////////////////////

#define solid_8_pixels(mask, dst)           \
    do {                                    \
        if (mask & 0x80) dst[0] = 0xFF;     \
        if (mask & 0x40) dst[1] = 0xFF;     \
        if (mask & 0x20) dst[2] = 0xFF;     \
        if (mask & 0x10) dst[3] = 0xFF;     \
        if (mask & 0x08) dst[4] = 0xFF;     \
        if (mask & 0x04) dst[5] = 0xFF;     \
        if (mask & 0x02) dst[6] = 0xFF;     \
        if (mask & 0x01) dst[7] = 0xFF;     \
    } while (0)

#define SK_BLITBWMASK_NAME                  SkA8_BlitBW
#define SK_BLITBWMASK_ARGS
#define SK_BLITBWMASK_BLIT8(mask, dst)      solid_8_pixels(mask, dst)
#define SK_BLITBWMASK_GETADDR               getAddr8
#define SK_BLITBWMASK_DEVTYPE               uint8_t
#include "SkBlitBWMaskTemplate.h"

static inline void blend_8_pixels(U8CPU bw, uint8_t dst[], U8CPU sa,
                                  unsigned dst_scale) {
    if (bw & 0x80) dst[0] = SkToU8(sa + SkAlphaMul(dst[0], dst_scale));
    if (bw & 0x40) dst[1] = SkToU8(sa + SkAlphaMul(dst[1], dst_scale));
    if (bw & 0x20) dst[2] = SkToU8(sa + SkAlphaMul(dst[2], dst_scale));
    if (bw & 0x10) dst[3] = SkToU8(sa + SkAlphaMul(dst[3], dst_scale));
    if (bw & 0x08) dst[4] = SkToU8(sa + SkAlphaMul(dst[4], dst_scale));
    if (bw & 0x04) dst[5] = SkToU8(sa + SkAlphaMul(dst[5], dst_scale));
    if (bw & 0x02) dst[6] = SkToU8(sa + SkAlphaMul(dst[6], dst_scale));
    if (bw & 0x01) dst[7] = SkToU8(sa + SkAlphaMul(dst[7], dst_scale));
}

#define SK_BLITBWMASK_NAME                  SkA8_BlendBW
#define SK_BLITBWMASK_ARGS                  , U8CPU sa, unsigned dst_scale
#define SK_BLITBWMASK_BLIT8(mask, dst)      blend_8_pixels(mask, dst, sa, dst_scale)
#define SK_BLITBWMASK_GETADDR               getAddr8
#define SK_BLITBWMASK_DEVTYPE               uint8_t
#include "SkBlitBWMaskTemplate.h"

void SkA8_Blitter::blitMask(const SkMask& mask, const SkIRect& clip) {
    if (fSrcA == 0) {
        return;
    }

    if (mask.fFormat == SkMask::kBW_Format) {
        if (fSrcA == 0xFF) {
            SkA8_BlitBW(fDevice, mask, clip);
        } else {
            SkA8_BlendBW(fDevice, mask, clip, fSrcA,
                         SkAlpha255To256(255 - fSrcA));
        }
        return;
    }

    int x = clip.fLeft;
    int y = clip.fTop;
    int width = clip.width();
    int height = clip.height();
    uint8_t* device = fDevice.getAddr8(x, y);
    const uint8_t* alpha = mask.getAddr8(x, y);
    unsigned    srcA = fSrcA;

    while (--height >= 0) {
        for (int i = width - 1; i >= 0; --i) {
            unsigned sa;
            // scale our src by the alpha value
            {
                int aa = alpha[i];
                if (aa == 0) {
                    continue;
                }
                if (aa == 255) {
                    if (srcA == 255) {
                        device[i] = 0xFF;
                        continue;
                    }
                    sa = srcA;
                } else {
                    sa = SkAlphaMul(srcA, SkAlpha255To256(aa));
                }
            }

            int scale = 256 - SkAlpha255To256(sa);
            device[i] = SkToU8(sa + SkAlphaMul(device[i], scale));
        }
        device += fDevice.rowBytes();
        alpha += mask.fRowBytes;
    }
}

///////////////////////////////////////////////////////////////////////////////

void SkA8_Blitter::blitV(int x, int y, int height, SkAlpha alpha) {
    if (fSrcA == 0) {
        return;
    }

    unsigned sa = SkAlphaMul(fSrcA, SkAlpha255To256(alpha));
    uint8_t* device = fDevice.getAddr8(x, y);
    int      rowBytes = fDevice.rowBytes();

    if (sa == 0xFF) {
        for (int i = 0; i < height; i++) {
            *device = SkToU8(sa);
            device += rowBytes;
        }
    } else {
        unsigned scale = 256 - SkAlpha255To256(sa);

        for (int i = 0; i < height; i++) {
            *device = SkToU8(sa + SkAlphaMul(*device, scale));
            device += rowBytes;
        }
    }
}

void SkA8_Blitter::blitRect(int x, int y, int width, int height) {
    SkASSERT(x >= 0 && y >= 0 &&
             (unsigned)(x + width) <= (unsigned)fDevice.width() &&
             (unsigned)(y + height) <= (unsigned)fDevice.height());

    if (fSrcA == 0) {
        return;
    }

    uint8_t*    device = fDevice.getAddr8(x, y);
    unsigned    srcA = fSrcA;

    if (srcA == 255) {
        while (--height >= 0) {
            memset(device, 0xFF, width);
            device += fDevice.rowBytes();
        }
    } else {
        unsigned scale = 256 - SkAlpha255To256(srcA);

        while (--height >= 0) {
            for (int i = 0; i < width; i++) {
                device[i] = SkToU8(srcA + SkAlphaMul(device[i], scale));
            }
            device += fDevice.rowBytes();
        }
    }
}

///////////////////////////////////////////////////////////////////////

SkA8_Shader_Blitter::SkA8_Shader_Blitter(const SkBitmap& device, const SkPaint& paint)
    : INHERITED(device, paint) {
    if ((fXfermode = paint.getXfermode()) != NULL) {
        fXfermode->ref();
        SkASSERT(fShader);
    }

    int width = device.width();
    fBuffer = (SkPMColor*)sk_malloc_throw(sizeof(SkPMColor) * (width + (SkAlign4(width) >> 2)));
    fAAExpand = (uint8_t*)(fBuffer + width);
}

SkA8_Shader_Blitter::~SkA8_Shader_Blitter() {
    if (fXfermode) SkSafeUnref(fXfermode);
    sk_free(fBuffer);
}

void SkA8_Shader_Blitter::blitH(int x, int y, int width) {
    SkASSERT(x >= 0 && y >= 0 &&
             (unsigned)(x + width) <= (unsigned)fDevice.width());

    uint8_t* device = fDevice.getAddr8(x, y);

    if ((fShader->getFlags() & SkShader::kOpaqueAlpha_Flag) && !fXfermode) {
        memset(device, 0xFF, width);
    } else {
        SkPMColor*  span = fBuffer;

        fShader->shadeSpan(x, y, span, width);
        if (fXfermode) {
            fXfermode->xferA8(device, span, width, NULL);
        } else {
            for (int i = width - 1; i >= 0; --i) {
                unsigned    srcA = SkGetPackedA32(span[i]);
                unsigned    scale = 256 - SkAlpha255To256(srcA);

                device[i] = SkToU8(srcA + SkAlphaMul(device[i], scale));
            }
        }
    }
}

static inline uint8_t aa_blend8(SkPMColor src, U8CPU da, int aa) {
    SkASSERT((unsigned)aa <= 255);

    int src_scale = SkAlpha255To256(aa);
    int sa = SkGetPackedA32(src);
    int dst_scale = 256 - SkAlphaMul(sa, src_scale);

    return SkToU8((sa * src_scale + da * dst_scale) >> 8);
}

void SkA8_Shader_Blitter::blitAntiH(int x, int y, const SkAlpha antialias[],
                                    const int16_t runs[]) {
    SkShader*   shader = fShader;
    SkXfermode* mode = fXfermode;
    uint8_t*    aaExpand = fAAExpand;
    SkPMColor*  span = fBuffer;
    uint8_t*    device = fDevice.getAddr8(x, y);
    int         opaque = fShader->getFlags() & SkShader::kOpaqueAlpha_Flag;

    for (;;) {
        int count = *runs;
        if (count == 0) {
            break;
        }
        int aa = *antialias;
        if (aa) {
            if (opaque && aa == 255 && mode == NULL) {
                memset(device, 0xFF, count);
            } else {
                shader->shadeSpan(x, y, span, count);
                if (mode) {
                    memset(aaExpand, aa, count);
                    mode->xferA8(device, span, count, aaExpand);
                } else {
                    for (int i = count - 1; i >= 0; --i) {
                        device[i] = aa_blend8(span[i], device[i], aa);
                    }
                }
            }
        }
        device += count;
        runs += count;
        antialias += count;
        x += count;
    }
}

void SkA8_Shader_Blitter::blitMask(const SkMask& mask, const SkIRect& clip) {
    if (mask.fFormat == SkMask::kBW_Format) {
        this->INHERITED::blitMask(mask, clip);
        return;
    }

    int x = clip.fLeft;
    int y = clip.fTop;
    int width = clip.width();
    int height = clip.height();
    uint8_t* device = fDevice.getAddr8(x, y);
    const uint8_t* alpha = mask.getAddr8(x, y);

    SkPMColor*  span = fBuffer;

    while (--height >= 0) {
        fShader->shadeSpan(x, y, span, width);
        if (fXfermode) {
            fXfermode->xferA8(device, span, width, alpha);
        }

        y += 1;
        device += fDevice.rowBytes();
        alpha += mask.fRowBytes;
    }
}