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 #include "SkColorPriv.h"
12 #include "SkDither.h"
13 #include "SkShader.h"
14 #include "SkTemplatesPriv.h"
15 #include "SkUtils.h"
16 #include "SkXfermode.h"
17
SkBlendARGB4444(SkPMColor16 src,SkPMColor16 dst,U8CPU aa)18 static inline SkPMColor SkBlendARGB4444(SkPMColor16 src, SkPMColor16 dst,
19 U8CPU aa) {
20 SkASSERT((unsigned)aa <= 255);
21
22 unsigned src_scale = SkAlpha255To256(aa) >> 4;
23 unsigned dst_scale = SkAlpha15To16(15 - SkAlphaMul4(SkGetPackedA4444(src), src_scale));
24
25 uint32_t src32 = SkExpand_4444(src) * src_scale;
26 uint32_t dst32 = SkExpand_4444(dst) * dst_scale;
27 return SkCompact_4444((src32 + dst32) >> 4);
28 }
29
30 ///////////////////////////////////////////////////////////////////////////////
31
32 class SkARGB4444_Blitter : public SkRasterBlitter {
33 public:
34 SkARGB4444_Blitter(const SkBitmap& device, const SkPaint& paint);
35 virtual void blitH(int x, int y, int width);
36 virtual void blitAntiH(int x, int y, const SkAlpha antialias[],
37 const int16_t runs[]);
38 virtual void blitV(int x, int y, int height, SkAlpha alpha);
39 virtual void blitRect(int x, int y, int width, int height);
40 virtual void blitMask(const SkMask&, const SkIRect&);
41 virtual const SkBitmap* justAnOpaqueColor(uint32_t*);
42
43 protected:
44 SkPMColor16 fPMColor16, fPMColor16Other;
45 SkPMColor16 fRawColor16, fRawColor16Other;
46 uint8_t fScale16;
47
48 private:
49 // illegal
50 SkARGB4444_Blitter& operator=(const SkARGB4444_Blitter&);
51
52 typedef SkRasterBlitter INHERITED;
53 };
54
55
SkARGB4444_Blitter(const SkBitmap & device,const SkPaint & paint)56 SkARGB4444_Blitter::SkARGB4444_Blitter(const SkBitmap& device,
57 const SkPaint& paint) : INHERITED(device) {
58 // cache premultiplied versions in 4444
59 SkPMColor c = SkPreMultiplyColor(paint.getColor());
60 fPMColor16 = SkPixel32ToPixel4444(c);
61 if (paint.isDither()) {
62 fPMColor16Other = SkDitherPixel32To4444(c);
63 } else {
64 fPMColor16Other = fPMColor16;
65 }
66
67 // cache raw versions in 4444
68 fRawColor16 = SkPackARGB4444(0xFF >> 4, SkColorGetR(c) >> 4,
69 SkColorGetG(c) >> 4, SkColorGetB(c) >> 4);
70 if (paint.isDither()) {
71 fRawColor16Other = SkDitherARGB32To4444(0xFF, SkColorGetR(c),
72 SkColorGetG(c), SkColorGetB(c));
73 } else {
74 fRawColor16Other = fRawColor16;
75 }
76
77 fScale16 = SkAlpha15To16(SkGetPackedA4444(fPMColor16Other));
78 if (16 == fScale16) {
79 // force the original to also be opaque
80 fPMColor16 |= (0xF << SK_A4444_SHIFT);
81 }
82 }
83
justAnOpaqueColor(uint32_t * value)84 const SkBitmap* SkARGB4444_Blitter::justAnOpaqueColor(uint32_t* value) {
85 if (16 == fScale16) {
86 *value = fPMColor16;
87 return &fDevice;
88 }
89 return NULL;
90 }
91
src_over_4444(SkPMColor16 dst[],SkPMColor16 color,SkPMColor16 other,unsigned invScale,int count)92 static void src_over_4444(SkPMColor16 dst[], SkPMColor16 color,
93 SkPMColor16 other, unsigned invScale, int count) {
94 int twice = count >> 1;
95 while (--twice >= 0) {
96 *dst = color + SkAlphaMulQ4(*dst, invScale);
97 dst++;
98 *dst = other + SkAlphaMulQ4(*dst, invScale);
99 dst++;
100 }
101 if (count & 1) {
102 *dst = color + SkAlphaMulQ4(*dst, invScale);
103 }
104 }
105
SkExpand_4444_Replicate(SkPMColor16 c)106 static inline uint32_t SkExpand_4444_Replicate(SkPMColor16 c) {
107 uint32_t c32 = SkExpand_4444(c);
108 return c32 | (c32 << 4);
109 }
110
src_over_4444x(SkPMColor16 dst[],uint32_t color,uint32_t other,unsigned invScale,int count)111 static void src_over_4444x(SkPMColor16 dst[], uint32_t color,
112 uint32_t other, unsigned invScale, int count) {
113 int twice = count >> 1;
114 uint32_t tmp;
115 while (--twice >= 0) {
116 tmp = SkExpand_4444(*dst) * invScale;
117 *dst++ = SkCompact_4444((color + tmp) >> 4);
118 tmp = SkExpand_4444(*dst) * invScale;
119 *dst++ = SkCompact_4444((other + tmp) >> 4);
120 }
121 if (count & 1) {
122 tmp = SkExpand_4444(*dst) * invScale;
123 *dst = SkCompact_4444((color + tmp) >> 4);
124 }
125 }
126
blitH(int x,int y,int width)127 void SkARGB4444_Blitter::blitH(int x, int y, int width) {
128 SkASSERT(x >= 0 && y >= 0 && x + width <= fDevice.width());
129
130 if (0 == fScale16) {
131 return;
132 }
133
134 SkPMColor16* device = fDevice.getAddr16(x, y);
135 SkPMColor16 color = fPMColor16;
136 SkPMColor16 other = fPMColor16Other;
137
138 if ((x ^ y) & 1) {
139 SkTSwap<SkPMColor16>(color, other);
140 }
141
142 if (16 == fScale16) {
143 sk_dither_memset16(device, color, other, width);
144 } else {
145 src_over_4444x(device, SkExpand_4444_Replicate(color),
146 SkExpand_4444_Replicate(other),
147 16 - fScale16, width);
148 }
149 }
150
blitV(int x,int y,int height,SkAlpha alpha)151 void SkARGB4444_Blitter::blitV(int x, int y, int height, SkAlpha alpha) {
152 if (0 == alpha || 0 == fScale16) {
153 return;
154 }
155
156 SkPMColor16* device = fDevice.getAddr16(x, y);
157 SkPMColor16 color = fPMColor16;
158 SkPMColor16 other = fPMColor16Other;
159 unsigned rb = fDevice.rowBytes();
160
161 if ((x ^ y) & 1) {
162 SkTSwap<SkPMColor16>(color, other);
163 }
164
165 if (16 == fScale16 && 255 == alpha) {
166 while (--height >= 0) {
167 *device = color;
168 device = (SkPMColor16*)((char*)device + rb);
169 SkTSwap<SkPMColor16>(color, other);
170 }
171 } else {
172 unsigned alphaScale = SkAlpha255To256(alpha);
173 uint32_t c32 = SkExpand_4444(color) * (alphaScale >> 4);
174 // need to normalize the low nibble of each expanded component
175 // so we don't overflow the add with d32
176 c32 = SkCompact_4444(c32 >> 4);
177 unsigned invScale = 16 - SkAlpha15To16(SkGetPackedA4444(c32));
178 // now re-expand and replicate
179 c32 = SkExpand_4444_Replicate(c32);
180
181 while (--height >= 0) {
182 uint32_t d32 = SkExpand_4444(*device) * invScale;
183 *device = SkCompact_4444((c32 + d32) >> 4);
184 device = (SkPMColor16*)((char*)device + rb);
185 }
186 }
187 }
188
blitRect(int x,int y,int width,int height)189 void SkARGB4444_Blitter::blitRect(int x, int y, int width, int height) {
190 SkASSERT(x >= 0 && y >= 0 && x + width <= fDevice.width() &&
191 y + height <= fDevice.height());
192
193 if (0 == fScale16) {
194 return;
195 }
196
197 SkPMColor16* device = fDevice.getAddr16(x, y);
198 SkPMColor16 color = fPMColor16;
199 SkPMColor16 other = fPMColor16Other;
200
201 if ((x ^ y) & 1) {
202 SkTSwap<SkPMColor16>(color, other);
203 }
204
205 if (16 == fScale16) {
206 while (--height >= 0) {
207 sk_dither_memset16(device, color, other, width);
208 device = (SkPMColor16*)((char*)device + fDevice.rowBytes());
209 SkTSwap<SkPMColor16>(color, other);
210 }
211 } else {
212 unsigned invScale = 16 - fScale16;
213
214 uint32_t c32 = SkExpand_4444_Replicate(color);
215 uint32_t o32 = SkExpand_4444_Replicate(other);
216 while (--height >= 0) {
217 src_over_4444x(device, c32, o32, invScale, width);
218 device = (SkPMColor16*)((char*)device + fDevice.rowBytes());
219 SkTSwap<uint32_t>(c32, o32);
220 }
221 }
222 }
223
blitAntiH(int x,int y,const SkAlpha antialias[],const int16_t runs[])224 void SkARGB4444_Blitter::blitAntiH(int x, int y, const SkAlpha antialias[],
225 const int16_t runs[]) {
226 if (0 == fScale16) {
227 return;
228 }
229
230 SkPMColor16* device = fDevice.getAddr16(x, y);
231 SkPMColor16 color = fPMColor16;
232 SkPMColor16 other = fPMColor16Other;
233
234 if ((x ^ y) & 1) {
235 SkTSwap<SkPMColor16>(color, other);
236 }
237
238 for (;;) {
239 int count = runs[0];
240 SkASSERT(count >= 0);
241 if (count <= 0) {
242 return;
243 }
244
245 unsigned aa = antialias[0];
246 if (aa) {
247 if (0xFF == aa) {
248 if (16 == fScale16) {
249 sk_dither_memset16(device, color, other, count);
250 } else {
251 src_over_4444(device, color, other, 16 - fScale16, count);
252 }
253 } else {
254 // todo: respect dithering
255 aa = SkAlpha255To256(aa); // FIX
256 SkPMColor16 src = SkAlphaMulQ4(color, aa >> 4);
257 unsigned dst_scale = SkAlpha15To16(15 - SkGetPackedA4444(src)); // FIX
258 int n = count;
259 do {
260 --n;
261 device[n] = src + SkAlphaMulQ4(device[n], dst_scale);
262 } while (n > 0);
263 }
264 }
265
266 runs += count;
267 antialias += count;
268 device += count;
269
270 if (count & 1) {
271 SkTSwap<SkPMColor16>(color, other);
272 }
273 }
274 }
275
276 ///////////////////////////////////////////////////////////////////////////////
277
278 #define solid_8_pixels(mask, dst, color) \
279 do { \
280 if (mask & 0x80) dst[0] = color; \
281 if (mask & 0x40) dst[1] = color; \
282 if (mask & 0x20) dst[2] = color; \
283 if (mask & 0x10) dst[3] = color; \
284 if (mask & 0x08) dst[4] = color; \
285 if (mask & 0x04) dst[5] = color; \
286 if (mask & 0x02) dst[6] = color; \
287 if (mask & 0x01) dst[7] = color; \
288 } while (0)
289
290 #define SK_BLITBWMASK_NAME SkARGB4444_BlitBW
291 #define SK_BLITBWMASK_ARGS , SkPMColor16 color
292 #define SK_BLITBWMASK_BLIT8(mask, dst) solid_8_pixels(mask, dst, color)
293 #define SK_BLITBWMASK_GETADDR getAddr16
294 #define SK_BLITBWMASK_DEVTYPE uint16_t
295 #include "SkBlitBWMaskTemplate.h"
296
297 #define blend_8_pixels(mask, dst, sc, dst_scale) \
298 do { \
299 if (mask & 0x80) { dst[0] = sc + SkAlphaMulQ4(dst[0], dst_scale); } \
300 if (mask & 0x40) { dst[1] = sc + SkAlphaMulQ4(dst[1], dst_scale); } \
301 if (mask & 0x20) { dst[2] = sc + SkAlphaMulQ4(dst[2], dst_scale); } \
302 if (mask & 0x10) { dst[3] = sc + SkAlphaMulQ4(dst[3], dst_scale); } \
303 if (mask & 0x08) { dst[4] = sc + SkAlphaMulQ4(dst[4], dst_scale); } \
304 if (mask & 0x04) { dst[5] = sc + SkAlphaMulQ4(dst[5], dst_scale); } \
305 if (mask & 0x02) { dst[6] = sc + SkAlphaMulQ4(dst[6], dst_scale); } \
306 if (mask & 0x01) { dst[7] = sc + SkAlphaMulQ4(dst[7], dst_scale); } \
307 } while (0)
308
309 #define SK_BLITBWMASK_NAME SkARGB4444_BlendBW
310 #define SK_BLITBWMASK_ARGS , uint16_t sc, unsigned dst_scale
311 #define SK_BLITBWMASK_BLIT8(mask, dst) blend_8_pixels(mask, dst, sc, dst_scale)
312 #define SK_BLITBWMASK_GETADDR getAddr16
313 #define SK_BLITBWMASK_DEVTYPE uint16_t
314 #include "SkBlitBWMaskTemplate.h"
315
blitMask(const SkMask & mask,const SkIRect & clip)316 void SkARGB4444_Blitter::blitMask(const SkMask& mask, const SkIRect& clip) {
317 SkASSERT(mask.fBounds.contains(clip));
318
319 if (0 == fScale16) {
320 return;
321 }
322
323 if (mask.fFormat == SkMask::kBW_Format) {
324 if (16 == fScale16) {
325 SkARGB4444_BlitBW(fDevice, mask, clip, fPMColor16);
326 } else {
327 SkARGB4444_BlendBW(fDevice, mask, clip, fPMColor16, 16 - fScale16);
328 }
329 return;
330 }
331
332 int x = clip.fLeft;
333 int y = clip.fTop;
334 int width = clip.width();
335 int height = clip.height();
336
337 SkPMColor16* device = fDevice.getAddr16(x, y);
338 const uint8_t* alpha = mask.getAddr8(x, y);
339 SkPMColor16 srcColor = fPMColor16;
340 unsigned devRB = fDevice.rowBytes() - (width << 1);
341 unsigned maskRB = mask.fRowBytes - width;
342
343 do {
344 int w = width;
345 do {
346 unsigned aa = *alpha++;
347 *device = SkBlendARGB4444(srcColor, *device, aa);
348 device += 1;
349 } while (--w != 0);
350 device = (SkPMColor16*)((char*)device + devRB);
351 alpha += maskRB;
352 } while (--height != 0);
353 }
354
355 ///////////////////////////////////////////////////////////////////////////////
356
357 class SkARGB4444_Shader_Blitter : public SkShaderBlitter {
358 SkXfermode* fXfermode;
359 SkBlitRow::Proc fOpaqueProc;
360 SkBlitRow::Proc fAlphaProc;
361 SkPMColor* fBuffer;
362 uint8_t* fAAExpand;
363 public:
364
SkARGB4444_Shader_Blitter(const SkBitmap & device,const SkPaint & paint)365 SkARGB4444_Shader_Blitter(const SkBitmap& device, const SkPaint& paint)
366 : INHERITED(device, paint) {
367 const int width = device.width();
368 fBuffer = (SkPMColor*)sk_malloc_throw(width * sizeof(SkPMColor) + width);
369 fAAExpand = (uint8_t*)(fBuffer + width);
370
371 fXfermode = paint.getXfermode();
372 SkSafeRef(fXfermode);
373
374 unsigned flags = 0;
375 if (!(fShader->getFlags() & SkShader::kOpaqueAlpha_Flag)) {
376 flags |= SkBlitRow::kSrcPixelAlpha_Flag;
377 }
378 if (paint.isDither()) {
379 flags |= SkBlitRow::kDither_Flag;
380 }
381 fOpaqueProc = SkBlitRow::Factory(flags, SkBitmap::kARGB_4444_Config);
382 fAlphaProc = SkBlitRow::Factory(flags | SkBlitRow::kGlobalAlpha_Flag,
383 SkBitmap::kARGB_4444_Config);
384 }
385
~SkARGB4444_Shader_Blitter()386 virtual ~SkARGB4444_Shader_Blitter() {
387 SkSafeUnref(fXfermode);
388 sk_free(fBuffer);
389 }
390
blitH(int x,int y,int width)391 virtual void blitH(int x, int y, int width) {
392 SkASSERT(x >= 0 && y >= 0 && x + width <= fDevice.width());
393
394 SkPMColor16* device = fDevice.getAddr16(x, y);
395 SkPMColor* span = fBuffer;
396
397 fShader->shadeSpan(x, y, span, width);
398 if (fXfermode) {
399 fXfermode->xfer4444(device, span, width, NULL);
400 } else {
401 fOpaqueProc(device, span, width, 0xFF, x, y);
402 }
403 }
404
blitAntiH(int x,int y,const SkAlpha antialias[],const int16_t runs[])405 virtual void blitAntiH(int x, int y, const SkAlpha antialias[],
406 const int16_t runs[]) {
407 SkPMColor* SK_RESTRICT span = fBuffer;
408 uint8_t* SK_RESTRICT aaExpand = fAAExpand;
409 SkPMColor16* device = fDevice.getAddr16(x, y);
410 SkShader* shader = fShader;
411 SkXfermode* xfer = fXfermode;
412
413 if (NULL != xfer) {
414 for (;;) {
415 int count = *runs;
416 if (count <= 0) {
417 break;
418 }
419 int aa = *antialias;
420 if (aa) {
421 shader->shadeSpan(x, y, span, count);
422 if (255 == aa) {
423 xfer->xfer4444(device, span, count, NULL);
424 } else {
425 const uint8_t* aaBuffer = antialias;
426 if (count > 1) {
427 memset(aaExpand, aa, count);
428 aaBuffer = aaExpand;
429 }
430 xfer->xfer4444(device, span, count, aaBuffer);
431 }
432 }
433 device += count;
434 runs += count;
435 antialias += count;
436 x += count;
437 }
438 } else { // no xfermode
439 for (;;) {
440 int count = *runs;
441 if (count <= 0) {
442 break;
443 }
444 int aa = *antialias;
445 if (aa) {
446 fShader->shadeSpan(x, y, span, count);
447 if (255 == aa) {
448 fOpaqueProc(device, span, count, aa, x, y);
449 } else {
450 fAlphaProc(device, span, count, aa, x, y);
451 }
452 }
453 device += count;
454 runs += count;
455 antialias += count;
456 x += count;
457 }
458 }
459 }
460
461 private:
462 typedef SkShaderBlitter INHERITED;
463 };
464
465 ///////////////////////////////////////////////////////////////////////////////
466 ///////////////////////////////////////////////////////////////////////////////
467
SkBlitter_ChooseD4444(const SkBitmap & device,const SkPaint & paint,void * storage,size_t storageSize)468 SkBlitter* SkBlitter_ChooseD4444(const SkBitmap& device,
469 const SkPaint& paint,
470 void* storage, size_t storageSize)
471 {
472 SkBlitter* blitter;
473
474 if (paint.getShader()) {
475 SK_PLACEMENT_NEW_ARGS(blitter, SkARGB4444_Shader_Blitter, storage, storageSize, (device, paint));
476 } else {
477 SK_PLACEMENT_NEW_ARGS(blitter, SkARGB4444_Blitter, storage, storageSize, (device, paint));
478 }
479 return blitter;
480 }
481
482