1/*
2 * Copyright 2012 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 "SkBitmap.h"
9#include "SkMagnifierImageFilter.h"
10#include "SkColorPriv.h"
11#include "SkDevice.h"
12#include "SkReadBuffer.h"
13#include "SkWriteBuffer.h"
14#include "SkValidationUtils.h"
15
16////////////////////////////////////////////////////////////////////////////////
17#if SK_SUPPORT_GPU
18#include "GrInvariantOutput.h"
19#include "effects/GrSingleTextureEffect.h"
20#include "glsl/GrGLSLFragmentProcessor.h"
21#include "glsl/GrGLSLFragmentShaderBuilder.h"
22#include "glsl/GrGLSLProgramDataManager.h"
23#include "glsl/GrGLSLUniformHandler.h"
24
25class GrMagnifierEffect : public GrSingleTextureEffect {
26
27public:
28    static GrFragmentProcessor* Create(GrTexture* texture,
29                                       const SkRect& bounds,
30                                       float xOffset,
31                                       float yOffset,
32                                       float xInvZoom,
33                                       float yInvZoom,
34                                       float xInvInset,
35                                       float yInvInset) {
36        return new GrMagnifierEffect(texture, bounds, xOffset, yOffset, xInvZoom, yInvZoom, xInvInset,
37                                     yInvInset);
38    }
39
40    virtual ~GrMagnifierEffect() {};
41
42    const char* name() const override { return "Magnifier"; }
43
44    const SkRect& bounds() const { return fBounds; }    // Bounds of source image.
45    // Offset to apply to zoomed pixels, (srcRect position / texture size).
46    float x_offset() const { return fXOffset; }
47    float y_offset() const { return fYOffset; }
48
49    // Scale to apply to zoomed pixels (srcRect size / bounds size).
50    float x_inv_zoom() const { return fXInvZoom; }
51    float y_inv_zoom() const { return fYInvZoom; }
52
53    // 1/radius over which to transition from unzoomed to zoomed pixels (bounds size / inset).
54    float x_inv_inset() const { return fXInvInset; }
55    float y_inv_inset() const { return fYInvInset; }
56
57private:
58    GrMagnifierEffect(GrTexture* texture,
59                      const SkRect& bounds,
60                      float xOffset,
61                      float yOffset,
62                      float xInvZoom,
63                      float yInvZoom,
64                      float xInvInset,
65                      float yInvInset)
66        : INHERITED(texture, GrCoordTransform::MakeDivByTextureWHMatrix(texture))
67        , fBounds(bounds)
68        , fXOffset(xOffset)
69        , fYOffset(yOffset)
70        , fXInvZoom(xInvZoom)
71        , fYInvZoom(yInvZoom)
72        , fXInvInset(xInvInset)
73        , fYInvInset(yInvInset) {
74        this->initClassID<GrMagnifierEffect>();
75    }
76
77    GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
78
79    void onGetGLSLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;
80
81    bool onIsEqual(const GrFragmentProcessor&) const override;
82
83    void onComputeInvariantOutput(GrInvariantOutput* inout) const override;
84
85    GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
86
87    SkRect fBounds;
88    float fXOffset;
89    float fYOffset;
90    float fXInvZoom;
91    float fYInvZoom;
92    float fXInvInset;
93    float fYInvInset;
94
95    typedef GrSingleTextureEffect INHERITED;
96};
97
98// For brevity
99typedef GrGLSLProgramDataManager::UniformHandle UniformHandle;
100
101class GrGLMagnifierEffect : public GrGLSLFragmentProcessor {
102public:
103    void emitCode(EmitArgs&) override;
104
105protected:
106    void onSetData(const GrGLSLProgramDataManager&, const GrProcessor&) override;
107
108private:
109    UniformHandle       fOffsetVar;
110    UniformHandle       fInvZoomVar;
111    UniformHandle       fInvInsetVar;
112    UniformHandle       fBoundsVar;
113
114    typedef GrGLSLFragmentProcessor INHERITED;
115};
116
117void GrGLMagnifierEffect::emitCode(EmitArgs& args) {
118    GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
119    fOffsetVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
120                                            kVec2f_GrSLType, kDefault_GrSLPrecision,
121                                            "Offset");
122    fInvZoomVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
123                                             kVec2f_GrSLType, kDefault_GrSLPrecision,
124                                             "InvZoom");
125    fInvInsetVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
126                                              kVec2f_GrSLType, kDefault_GrSLPrecision,
127                                              "InvInset");
128    fBoundsVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
129                                            kVec4f_GrSLType, kDefault_GrSLPrecision,
130                                            "Bounds");
131
132    GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
133    SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
134    fragBuilder->codeAppendf("\t\tvec2 coord = %s;\n", coords2D.c_str());
135    fragBuilder->codeAppendf("\t\tvec2 zoom_coord = %s + %s * %s;\n",
136                             uniformHandler->getUniformCStr(fOffsetVar),
137                             coords2D.c_str(),
138                             uniformHandler->getUniformCStr(fInvZoomVar));
139    const char* bounds = uniformHandler->getUniformCStr(fBoundsVar);
140    fragBuilder->codeAppendf("\t\tvec2 delta = (coord - %s.xy) * %s.zw;\n", bounds, bounds);
141    fragBuilder->codeAppendf("\t\tdelta = min(delta, vec2(1.0, 1.0) - delta);\n");
142    fragBuilder->codeAppendf("\t\tdelta = delta * %s;\n",
143                             uniformHandler->getUniformCStr(fInvInsetVar));
144
145    fragBuilder->codeAppend("\t\tfloat weight = 0.0;\n");
146    fragBuilder->codeAppend("\t\tif (delta.s < 2.0 && delta.t < 2.0) {\n");
147    fragBuilder->codeAppend("\t\t\tdelta = vec2(2.0, 2.0) - delta;\n");
148    fragBuilder->codeAppend("\t\t\tfloat dist = length(delta);\n");
149    fragBuilder->codeAppend("\t\t\tdist = max(2.0 - dist, 0.0);\n");
150    fragBuilder->codeAppend("\t\t\tweight = min(dist * dist, 1.0);\n");
151    fragBuilder->codeAppend("\t\t} else {\n");
152    fragBuilder->codeAppend("\t\t\tvec2 delta_squared = delta * delta;\n");
153    fragBuilder->codeAppend("\t\t\tweight = min(min(delta_squared.x, delta_squared.y), 1.0);\n");
154    fragBuilder->codeAppend("\t\t}\n");
155
156    fragBuilder->codeAppend("\t\tvec2 mix_coord = mix(coord, zoom_coord, weight);\n");
157    fragBuilder->codeAppend("\t\tvec4 output_color = ");
158    fragBuilder->appendTextureLookup(args.fSamplers[0], "mix_coord");
159    fragBuilder->codeAppend(";\n");
160
161    fragBuilder->codeAppendf("\t\t%s = output_color;", args.fOutputColor);
162    SkString modulate;
163    GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
164    fragBuilder->codeAppend(modulate.c_str());
165}
166
167void GrGLMagnifierEffect::onSetData(const GrGLSLProgramDataManager& pdman,
168                                    const GrProcessor& effect) {
169    const GrMagnifierEffect& zoom = effect.cast<GrMagnifierEffect>();
170    pdman.set2f(fOffsetVar, zoom.x_offset(), zoom.y_offset());
171    pdman.set2f(fInvZoomVar, zoom.x_inv_zoom(), zoom.y_inv_zoom());
172    pdman.set2f(fInvInsetVar, zoom.x_inv_inset(), zoom.y_inv_inset());
173    pdman.set4f(fBoundsVar, zoom.bounds().x(), zoom.bounds().y(),
174                            zoom.bounds().width(), zoom.bounds().height());
175}
176
177/////////////////////////////////////////////////////////////////////
178
179void GrMagnifierEffect::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
180                                              GrProcessorKeyBuilder* b) const {
181    GrGLMagnifierEffect::GenKey(*this, caps, b);
182}
183
184GrGLSLFragmentProcessor* GrMagnifierEffect::onCreateGLSLInstance() const {
185    return new GrGLMagnifierEffect;
186}
187
188GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrMagnifierEffect);
189
190const GrFragmentProcessor* GrMagnifierEffect::TestCreate(GrProcessorTestData* d) {
191    GrTexture* texture = d->fTextures[0];
192    const int kMaxWidth = 200;
193    const int kMaxHeight = 200;
194    const int kMaxInset = 20;
195    uint32_t width = d->fRandom->nextULessThan(kMaxWidth);
196    uint32_t height = d->fRandom->nextULessThan(kMaxHeight);
197    uint32_t x = d->fRandom->nextULessThan(kMaxWidth - width);
198    uint32_t y = d->fRandom->nextULessThan(kMaxHeight - height);
199    uint32_t inset = d->fRandom->nextULessThan(kMaxInset);
200
201    GrFragmentProcessor* effect = GrMagnifierEffect::Create(
202        texture,
203        SkRect::MakeWH(SkIntToScalar(kMaxWidth), SkIntToScalar(kMaxHeight)),
204        (float) width / texture->width(),
205        (float) height / texture->height(),
206        texture->width() / (float) x,
207        texture->height() / (float) y,
208        (float) inset / texture->width(),
209        (float) inset / texture->height());
210    SkASSERT(effect);
211    return effect;
212}
213
214///////////////////////////////////////////////////////////////////////////////
215
216bool GrMagnifierEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
217    const GrMagnifierEffect& s = sBase.cast<GrMagnifierEffect>();
218    return (this->fBounds == s.fBounds &&
219            this->fXOffset == s.fXOffset &&
220            this->fYOffset == s.fYOffset &&
221            this->fXInvZoom == s.fXInvZoom &&
222            this->fYInvZoom == s.fYInvZoom &&
223            this->fXInvInset == s.fXInvInset &&
224            this->fYInvInset == s.fYInvInset);
225}
226
227void GrMagnifierEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
228    this->updateInvariantOutputForModulation(inout);
229}
230
231#endif
232
233////////////////////////////////////////////////////////////////////////////////
234
235SkImageFilter* SkMagnifierImageFilter::Create(const SkRect& srcRect, SkScalar inset,
236                                              SkImageFilter* input) {
237
238    if (!SkScalarIsFinite(inset) || !SkIsValidRect(srcRect)) {
239        return nullptr;
240    }
241    // Negative numbers in src rect are not supported
242    if (srcRect.fLeft < 0 || srcRect.fTop < 0) {
243        return nullptr;
244    }
245    return new SkMagnifierImageFilter(srcRect, inset, input);
246}
247
248
249SkMagnifierImageFilter::SkMagnifierImageFilter(const SkRect& srcRect, SkScalar inset,
250                                               SkImageFilter* input)
251    : INHERITED(1, &input), fSrcRect(srcRect), fInset(inset) {
252    SkASSERT(srcRect.x() >= 0 && srcRect.y() >= 0 && inset >= 0);
253}
254
255#if SK_SUPPORT_GPU
256bool SkMagnifierImageFilter::asFragmentProcessor(GrFragmentProcessor** fp,
257                                                 GrTexture* texture, const SkMatrix&,
258                                                 const SkIRect&bounds) const {
259    if (fp) {
260        SkScalar yOffset = texture->origin() == kTopLeft_GrSurfaceOrigin ? fSrcRect.y() :
261           texture->height() - fSrcRect.height() * texture->height() / bounds.height()
262                             - fSrcRect.y();
263        int boundsY = (texture->origin() == kTopLeft_GrSurfaceOrigin) ? bounds.y() :
264                      (texture->height() - bounds.height());
265        SkRect effectBounds = SkRect::MakeXYWH(
266            SkIntToScalar(bounds.x()) / texture->width(),
267            SkIntToScalar(boundsY) / texture->height(),
268            SkIntToScalar(texture->width()) / bounds.width(),
269            SkIntToScalar(texture->height()) / bounds.height());
270        SkScalar invInset = fInset > 0 ? SkScalarInvert(fInset) : SK_Scalar1;
271        *fp = GrMagnifierEffect::Create(texture,
272                                        effectBounds,
273                                        fSrcRect.x() / texture->width(),
274                                        yOffset / texture->height(),
275                                        fSrcRect.width() / bounds.width(),
276                                        fSrcRect.height() / bounds.height(),
277                                        bounds.width() * invInset,
278                                        bounds.height() * invInset);
279    }
280    return true;
281}
282#endif
283
284SkFlattenable* SkMagnifierImageFilter::CreateProc(SkReadBuffer& buffer) {
285    SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
286    SkRect src;
287    buffer.readRect(&src);
288    return Create(src, buffer.readScalar(), common.getInput(0));
289}
290
291void SkMagnifierImageFilter::flatten(SkWriteBuffer& buffer) const {
292    this->INHERITED::flatten(buffer);
293    buffer.writeRect(fSrcRect);
294    buffer.writeScalar(fInset);
295}
296
297bool SkMagnifierImageFilter::onFilterImageDeprecated(Proxy* proxy, const SkBitmap& src,
298                                                     const Context&, SkBitmap* dst,
299                                                     SkIPoint* offset) const {
300    if ((src.colorType() != kN32_SkColorType) ||
301        (fSrcRect.width() >= src.width()) ||
302        (fSrcRect.height() >= src.height())) {
303      return false;
304    }
305
306    SkAutoLockPixels alp(src);
307    SkASSERT(src.getPixels());
308    if (!src.getPixels() || src.width() <= 0 || src.height() <= 0) {
309      return false;
310    }
311
312    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(src.width(), src.height()));
313    if (!device) {
314        return false;
315    }
316    *dst = device->accessBitmap(false);
317    SkAutoLockPixels alp_dst(*dst);
318
319    SkScalar inv_inset = fInset > 0 ? SkScalarInvert(fInset) : SK_Scalar1;
320
321    SkScalar inv_x_zoom = fSrcRect.width() / src.width();
322    SkScalar inv_y_zoom = fSrcRect.height() / src.height();
323
324    SkColor* sptr = src.getAddr32(0, 0);
325    SkColor* dptr = dst->getAddr32(0, 0);
326    int width = src.width(), height = src.height();
327    for (int y = 0; y < height; ++y) {
328        for (int x = 0; x < width; ++x) {
329            SkScalar x_dist = SkMin32(x, width - x - 1) * inv_inset;
330            SkScalar y_dist = SkMin32(y, height - y - 1) * inv_inset;
331            SkScalar weight = 0;
332
333            static const SkScalar kScalar2 = SkScalar(2);
334
335            // To create a smooth curve at the corners, we need to work on
336            // a square twice the size of the inset.
337            if (x_dist < kScalar2 && y_dist < kScalar2) {
338                x_dist = kScalar2 - x_dist;
339                y_dist = kScalar2 - y_dist;
340
341                SkScalar dist = SkScalarSqrt(SkScalarSquare(x_dist) +
342                                             SkScalarSquare(y_dist));
343                dist = SkMaxScalar(kScalar2 - dist, 0);
344                weight = SkMinScalar(SkScalarSquare(dist), SK_Scalar1);
345            } else {
346                SkScalar sqDist = SkMinScalar(SkScalarSquare(x_dist),
347                                              SkScalarSquare(y_dist));
348                weight = SkMinScalar(sqDist, SK_Scalar1);
349            }
350
351            SkScalar x_interp = SkScalarMul(weight, (fSrcRect.x() + x * inv_x_zoom)) +
352                           (SK_Scalar1 - weight) * x;
353            SkScalar y_interp = SkScalarMul(weight, (fSrcRect.y() + y * inv_y_zoom)) +
354                           (SK_Scalar1 - weight) * y;
355
356            int x_val = SkTPin(SkScalarFloorToInt(x_interp), 0, width - 1);
357            int y_val = SkTPin(SkScalarFloorToInt(y_interp), 0, height - 1);
358
359            *dptr = sptr[y_val * width + x_val];
360            dptr++;
361        }
362    }
363    return true;
364}
365
366#ifndef SK_IGNORE_TO_STRING
367void SkMagnifierImageFilter::toString(SkString* str) const {
368    str->appendf("SkMagnifierImageFilter: (");
369    str->appendf("src: (%f,%f,%f,%f) ",
370                 fSrcRect.fLeft, fSrcRect.fTop, fSrcRect.fRight, fSrcRect.fBottom);
371    str->appendf("inset: %f", fInset);
372    str->append(")");
373}
374#endif
375