1/*
2 * Copyright 2006 The Android Open Source Project
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkAtomics.h"
9#include "SkBitmapProcShader.h"
10#include "SkColorShader.h"
11#include "SkEmptyShader.h"
12#include "SkMallocPixelRef.h"
13#include "SkPaint.h"
14#include "SkPicture.h"
15#include "SkPictureShader.h"
16#include "SkReadBuffer.h"
17#include "SkScalar.h"
18#include "SkShader.h"
19#include "SkWriteBuffer.h"
20
21//#define SK_TRACK_SHADER_LIFETIME
22
23#ifdef SK_TRACK_SHADER_LIFETIME
24    static int32_t gShaderCounter;
25#endif
26
27static inline void inc_shader_counter() {
28#ifdef SK_TRACK_SHADER_LIFETIME
29    int32_t prev = sk_atomic_inc(&gShaderCounter);
30    SkDebugf("+++ shader counter %d\n", prev + 1);
31#endif
32}
33static inline void dec_shader_counter() {
34#ifdef SK_TRACK_SHADER_LIFETIME
35    int32_t prev = sk_atomic_dec(&gShaderCounter);
36    SkDebugf("--- shader counter %d\n", prev - 1);
37#endif
38}
39
40SkShader::SkShader(const SkMatrix* localMatrix) {
41    inc_shader_counter();
42    if (localMatrix) {
43        fLocalMatrix = *localMatrix;
44    } else {
45        fLocalMatrix.reset();
46    }
47    // Pre-cache so future calls to fLocalMatrix.getType() are threadsafe.
48    (void)fLocalMatrix.getType();
49}
50
51SkShader::~SkShader() {
52    dec_shader_counter();
53}
54
55void SkShader::flatten(SkWriteBuffer& buffer) const {
56    this->INHERITED::flatten(buffer);
57    bool hasLocalM = !fLocalMatrix.isIdentity();
58    buffer.writeBool(hasLocalM);
59    if (hasLocalM) {
60        buffer.writeMatrix(fLocalMatrix);
61    }
62}
63
64bool SkShader::computeTotalInverse(const ContextRec& rec, SkMatrix* totalInverse) const {
65    SkMatrix total;
66    total.setConcat(*rec.fMatrix, fLocalMatrix);
67
68    const SkMatrix* m = &total;
69    if (rec.fLocalMatrix) {
70        total.setConcat(*m, *rec.fLocalMatrix);
71        m = &total;
72    }
73    return m->invert(totalInverse);
74}
75
76bool SkShader::asLuminanceColor(SkColor* colorPtr) const {
77    SkColor storage;
78    if (nullptr == colorPtr) {
79        colorPtr = &storage;
80    }
81    if (this->onAsLuminanceColor(colorPtr)) {
82        *colorPtr = SkColorSetA(*colorPtr, 0xFF);   // we only return opaque
83        return true;
84    }
85    return false;
86}
87
88SkShader::Context* SkShader::createContext(const ContextRec& rec, void* storage) const {
89    if (!this->computeTotalInverse(rec, nullptr)) {
90        return nullptr;
91    }
92    return this->onCreateContext(rec, storage);
93}
94
95SkShader::Context* SkShader::onCreateContext(const ContextRec& rec, void*) const {
96    return nullptr;
97}
98
99size_t SkShader::contextSize(const ContextRec&) const {
100    return 0;
101}
102
103SkShader::Context::Context(const SkShader& shader, const ContextRec& rec)
104    : fShader(shader), fCTM(*rec.fMatrix)
105{
106    // Because the context parameters must be valid at this point, we know that the matrix is
107    // invertible.
108    SkAssertResult(fShader.computeTotalInverse(rec, &fTotalInverse));
109    fTotalInverseClass = (uint8_t)ComputeMatrixClass(fTotalInverse);
110
111    fPaintAlpha = rec.fPaint->getAlpha();
112}
113
114SkShader::Context::~Context() {}
115
116SkShader::Context::ShadeProc SkShader::Context::asAShadeProc(void** ctx) {
117    return nullptr;
118}
119
120void SkShader::Context::shadeSpan4f(int x, int y, SkPM4f dst[], int count) {
121    const int N = 128;
122    SkPMColor tmp[N];
123    while (count > 0) {
124        int n = SkTMin(count, N);
125        this->shadeSpan(x, y, tmp, n);
126        for (int i = 0; i < n; ++i) {
127            dst[i] = SkPM4f::FromPMColor(tmp[i]);
128        }
129        dst += n;
130        x += n;
131        count -= n;
132    }
133}
134
135#include "SkColorPriv.h"
136
137#define kTempColorQuadCount 6   // balance between speed (larger) and saving stack-space
138#define kTempColorCount     (kTempColorQuadCount << 2)
139
140#ifdef SK_CPU_BENDIAN
141    #define SkU32BitShiftToByteOffset(shift)    (3 - ((shift) >> 3))
142#else
143    #define SkU32BitShiftToByteOffset(shift)    ((shift) >> 3)
144#endif
145
146void SkShader::Context::shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) {
147    SkASSERT(count > 0);
148
149    SkPMColor   colors[kTempColorCount];
150
151    while ((count -= kTempColorCount) >= 0) {
152        this->shadeSpan(x, y, colors, kTempColorCount);
153        x += kTempColorCount;
154
155        const uint8_t* srcA = (const uint8_t*)colors + SkU32BitShiftToByteOffset(SK_A32_SHIFT);
156        int quads = kTempColorQuadCount;
157        do {
158            U8CPU a0 = srcA[0];
159            U8CPU a1 = srcA[4];
160            U8CPU a2 = srcA[8];
161            U8CPU a3 = srcA[12];
162            srcA += 4*4;
163            *alpha++ = SkToU8(a0);
164            *alpha++ = SkToU8(a1);
165            *alpha++ = SkToU8(a2);
166            *alpha++ = SkToU8(a3);
167        } while (--quads != 0);
168    }
169    SkASSERT(count < 0);
170    SkASSERT(count + kTempColorCount >= 0);
171    if (count += kTempColorCount) {
172        this->shadeSpan(x, y, colors, count);
173
174        const uint8_t* srcA = (const uint8_t*)colors + SkU32BitShiftToByteOffset(SK_A32_SHIFT);
175        do {
176            *alpha++ = *srcA;
177            srcA += 4;
178        } while (--count != 0);
179    }
180#if 0
181    do {
182        int n = count;
183        if (n > kTempColorCount)
184            n = kTempColorCount;
185        SkASSERT(n > 0);
186
187        this->shadeSpan(x, y, colors, n);
188        x += n;
189        count -= n;
190
191        const uint8_t* srcA = (const uint8_t*)colors + SkU32BitShiftToByteOffset(SK_A32_SHIFT);
192        do {
193            *alpha++ = *srcA;
194            srcA += 4;
195        } while (--n != 0);
196    } while (count > 0);
197#endif
198}
199
200SkShader::Context::MatrixClass SkShader::Context::ComputeMatrixClass(const SkMatrix& mat) {
201    MatrixClass mc = kLinear_MatrixClass;
202
203    if (mat.hasPerspective()) {
204        if (mat.isFixedStepInX()) {
205            mc = kFixedStepInX_MatrixClass;
206        } else {
207            mc = kPerspective_MatrixClass;
208        }
209    }
210    return mc;
211}
212
213//////////////////////////////////////////////////////////////////////////////
214
215SkShader::GradientType SkShader::asAGradient(GradientInfo* info) const {
216    return kNone_GradientType;
217}
218
219const GrFragmentProcessor* SkShader::asFragmentProcessor(GrContext*, const SkMatrix&,
220                                                         const SkMatrix*, SkFilterQuality)  const {
221    return nullptr;
222}
223
224SkShader* SkShader::refAsALocalMatrixShader(SkMatrix*) const {
225    return nullptr;
226}
227
228SkShader* SkShader::CreateEmptyShader() { return new SkEmptyShader; }
229
230SkShader* SkShader::CreateColorShader(SkColor color) { return new SkColorShader(color); }
231
232SkShader* SkShader::CreateBitmapShader(const SkBitmap& src, TileMode tmx, TileMode tmy,
233                                       const SkMatrix* localMatrix) {
234    return SkCreateBitmapShader(src, tmx, tmy, localMatrix, nullptr);
235}
236
237SkShader* SkShader::CreatePictureShader(const SkPicture* src, TileMode tmx, TileMode tmy,
238                                        const SkMatrix* localMatrix, const SkRect* tile) {
239    return SkPictureShader::Create(src, tmx, tmy, localMatrix, tile);
240}
241
242#ifndef SK_IGNORE_TO_STRING
243void SkShader::toString(SkString* str) const {
244    if (!fLocalMatrix.isIdentity()) {
245        str->append(" ");
246        fLocalMatrix.toString(str);
247    }
248}
249#endif
250
251//////////////////////////////////////////////////////////////////////////////
252
253#include "SkUtils.h"
254
255SkColorShader::SkColorShader(SkColor c)
256    : fColor(c) {
257}
258
259bool SkColorShader::isOpaque() const {
260    return SkColorGetA(fColor) == 255;
261}
262
263SkFlattenable* SkColorShader::CreateProc(SkReadBuffer& buffer) {
264    return new SkColorShader(buffer.readColor());
265}
266
267void SkColorShader::flatten(SkWriteBuffer& buffer) const {
268    buffer.writeColor(fColor);
269}
270
271uint32_t SkColorShader::ColorShaderContext::getFlags() const {
272    return fFlags;
273}
274
275SkShader::Context* SkColorShader::onCreateContext(const ContextRec& rec, void* storage) const {
276    return new (storage) ColorShaderContext(*this, rec);
277}
278
279SkColorShader::ColorShaderContext::ColorShaderContext(const SkColorShader& shader,
280                                                      const ContextRec& rec)
281    : INHERITED(shader, rec)
282{
283    SkColor color = shader.fColor;
284    unsigned a = SkAlphaMul(SkColorGetA(color), SkAlpha255To256(rec.fPaint->getAlpha()));
285
286    unsigned r = SkColorGetR(color);
287    unsigned g = SkColorGetG(color);
288    unsigned b = SkColorGetB(color);
289
290    if (a != 255) {
291        r = SkMulDiv255Round(r, a);
292        g = SkMulDiv255Round(g, a);
293        b = SkMulDiv255Round(b, a);
294    }
295    fPMColor = SkPackARGB32(a, r, g, b);
296
297    SkColor4f c4 = SkColor4f::FromColor(shader.fColor);
298    c4.fA *= rec.fPaint->getAlpha() / 255.0f;
299    fPM4f = c4.premul();
300
301    fFlags = kConstInY32_Flag;
302    if (255 == a) {
303        fFlags |= kOpaqueAlpha_Flag;
304    }
305}
306
307void SkColorShader::ColorShaderContext::shadeSpan(int x, int y, SkPMColor span[], int count) {
308    sk_memset32(span, fPMColor, count);
309}
310
311void SkColorShader::ColorShaderContext::shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) {
312    memset(alpha, SkGetPackedA32(fPMColor), count);
313}
314
315void SkColorShader::ColorShaderContext::shadeSpan4f(int x, int y, SkPM4f span[], int count) {
316    for (int i = 0; i < count; ++i) {
317        span[i] = fPM4f;
318    }
319}
320
321SkShader::GradientType SkColorShader::asAGradient(GradientInfo* info) const {
322    if (info) {
323        if (info->fColors && info->fColorCount >= 1) {
324            info->fColors[0] = fColor;
325        }
326        info->fColorCount = 1;
327        info->fTileMode = SkShader::kRepeat_TileMode;
328    }
329    return kColor_GradientType;
330}
331
332#if SK_SUPPORT_GPU
333
334#include "SkGr.h"
335#include "effects/GrConstColorProcessor.h"
336const GrFragmentProcessor* SkColorShader::asFragmentProcessor(GrContext*, const SkMatrix&,
337                                                              const SkMatrix*,
338                                                              SkFilterQuality) const {
339    GrColor color = SkColorToPremulGrColor(fColor);
340    return GrConstColorProcessor::Create(color, GrConstColorProcessor::kModulateA_InputMode);
341}
342
343#endif
344
345#ifndef SK_IGNORE_TO_STRING
346void SkColorShader::toString(SkString* str) const {
347    str->append("SkColorShader: (");
348
349    str->append("Color: ");
350    str->appendHex(fColor);
351
352    this->INHERITED::toString(str);
353
354    str->append(")");
355}
356#endif
357
358///////////////////////////////////////////////////////////////////////////////
359
360SkFlattenable* SkEmptyShader::CreateProc(SkReadBuffer&) {
361    return SkShader::CreateEmptyShader();
362}
363
364#ifndef SK_IGNORE_TO_STRING
365#include "SkEmptyShader.h"
366
367void SkEmptyShader::toString(SkString* str) const {
368    str->append("SkEmptyShader: (");
369
370    this->INHERITED::toString(str);
371
372    str->append(")");
373}
374#endif
375