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      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 "SkReadBuffer.h"
     12 #include "SkWriteBuffer.h"
     13 #include "SkValidationUtils.h"
     14 
     15 ////////////////////////////////////////////////////////////////////////////////
     16 #if SK_SUPPORT_GPU
     17 #include "effects/GrSingleTextureEffect.h"
     18 #include "gl/GrGLProcessor.h"
     19 #include "gl/builders/GrGLProgramBuilder.h"
     20 #include "gl/GrGLSL.h"
     21 #include "gl/GrGLTexture.h"
     22 #include "GrTBackendProcessorFactory.h"
     23 
     24 class GrGLMagnifierEffect;
     25 
     26 class GrMagnifierEffect : public GrSingleTextureEffect {
     27 
     28 public:
     29     static GrFragmentProcessor* Create(GrTexture* texture,
     30                                        float xOffset,
     31                                        float yOffset,
     32                                        float xInvZoom,
     33                                        float yInvZoom,
     34                                        float xInvInset,
     35                                        float yInvInset) {
     36         return SkNEW_ARGS(GrMagnifierEffect, (texture,
     37                                               xOffset,
     38                                               yOffset,
     39                                               xInvZoom,
     40                                               yInvZoom,
     41                                               xInvInset,
     42                                               yInvInset));
     43     }
     44 
     45     virtual ~GrMagnifierEffect() {};
     46 
     47     static const char* Name() { return "Magnifier"; }
     48 
     49     virtual const GrBackendFragmentProcessorFactory& getFactory() const SK_OVERRIDE;
     50     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
     51 
     52     float x_offset() const { return fXOffset; }
     53     float y_offset() const { return fYOffset; }
     54     float x_inv_zoom() const { return fXInvZoom; }
     55     float y_inv_zoom() const { return fYInvZoom; }
     56     float x_inv_inset() const { return fXInvInset; }
     57     float y_inv_inset() const { return fYInvInset; }
     58 
     59     typedef GrGLMagnifierEffect GLProcessor;
     60 
     61 private:
     62     GrMagnifierEffect(GrTexture* texture,
     63                       float xOffset,
     64                       float yOffset,
     65                       float xInvZoom,
     66                       float yInvZoom,
     67                       float xInvInset,
     68                       float yInvInset)
     69         : GrSingleTextureEffect(texture, GrCoordTransform::MakeDivByTextureWHMatrix(texture))
     70         , fXOffset(xOffset)
     71         , fYOffset(yOffset)
     72         , fXInvZoom(xInvZoom)
     73         , fYInvZoom(yInvZoom)
     74         , fXInvInset(xInvInset)
     75         , fYInvInset(yInvInset) {}
     76 
     77     virtual bool onIsEqual(const GrProcessor&) const SK_OVERRIDE;
     78 
     79     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
     80 
     81     float fXOffset;
     82     float fYOffset;
     83     float fXInvZoom;
     84     float fYInvZoom;
     85     float fXInvInset;
     86     float fYInvInset;
     87 
     88     typedef GrSingleTextureEffect INHERITED;
     89 };
     90 
     91 // For brevity
     92 typedef GrGLProgramDataManager::UniformHandle UniformHandle;
     93 
     94 class GrGLMagnifierEffect : public GrGLFragmentProcessor {
     95 public:
     96     GrGLMagnifierEffect(const GrBackendProcessorFactory&, const GrProcessor&);
     97 
     98     virtual void emitCode(GrGLProgramBuilder*,
     99                           const GrFragmentProcessor&,
    100                           const GrProcessorKey&,
    101                           const char* outputColor,
    102                           const char* inputColor,
    103                           const TransformedCoordsArray&,
    104                           const TextureSamplerArray&) SK_OVERRIDE;
    105 
    106     virtual void setData(const GrGLProgramDataManager&, const GrProcessor&) SK_OVERRIDE;
    107 
    108 private:
    109     UniformHandle       fOffsetVar;
    110     UniformHandle       fInvZoomVar;
    111     UniformHandle       fInvInsetVar;
    112 
    113     typedef GrGLFragmentProcessor INHERITED;
    114 };
    115 
    116 GrGLMagnifierEffect::GrGLMagnifierEffect(const GrBackendProcessorFactory& factory,
    117                                          const GrProcessor&)
    118     : INHERITED(factory) {
    119 }
    120 
    121 void GrGLMagnifierEffect::emitCode(GrGLProgramBuilder* builder,
    122                                    const GrFragmentProcessor&,
    123                                    const GrProcessorKey& key,
    124                                    const char* outputColor,
    125                                    const char* inputColor,
    126                                    const TransformedCoordsArray& coords,
    127                                    const TextureSamplerArray& samplers) {
    128     fOffsetVar = builder->addUniform(
    129         GrGLProgramBuilder::kFragment_Visibility |
    130         GrGLProgramBuilder::kVertex_Visibility,
    131         kVec2f_GrSLType, "Offset");
    132     fInvZoomVar = builder->addUniform(
    133         GrGLProgramBuilder::kFragment_Visibility |
    134         GrGLProgramBuilder::kVertex_Visibility,
    135         kVec2f_GrSLType, "InvZoom");
    136     fInvInsetVar = builder->addUniform(
    137         GrGLProgramBuilder::kFragment_Visibility |
    138         GrGLProgramBuilder::kVertex_Visibility,
    139         kVec2f_GrSLType, "InvInset");
    140 
    141     GrGLFragmentShaderBuilder* fsBuilder = builder->getFragmentShaderBuilder();
    142     SkString coords2D = fsBuilder->ensureFSCoords2D(coords, 0);
    143     fsBuilder->codeAppendf("\t\tvec2 coord = %s;\n", coords2D.c_str());
    144     fsBuilder->codeAppendf("\t\tvec2 zoom_coord = %s + %s * %s;\n",
    145                            builder->getUniformCStr(fOffsetVar),
    146                            coords2D.c_str(),
    147                            builder->getUniformCStr(fInvZoomVar));
    148 
    149     fsBuilder->codeAppend("\t\tvec2 delta = min(coord, vec2(1.0, 1.0) - coord);\n");
    150 
    151     fsBuilder->codeAppendf("\t\tdelta = delta * %s;\n", builder->getUniformCStr(fInvInsetVar));
    152 
    153     fsBuilder->codeAppend("\t\tfloat weight = 0.0;\n");
    154     fsBuilder->codeAppend("\t\tif (delta.s < 2.0 && delta.t < 2.0) {\n");
    155     fsBuilder->codeAppend("\t\t\tdelta = vec2(2.0, 2.0) - delta;\n");
    156     fsBuilder->codeAppend("\t\t\tfloat dist = length(delta);\n");
    157     fsBuilder->codeAppend("\t\t\tdist = max(2.0 - dist, 0.0);\n");
    158     fsBuilder->codeAppend("\t\t\tweight = min(dist * dist, 1.0);\n");
    159     fsBuilder->codeAppend("\t\t} else {\n");
    160     fsBuilder->codeAppend("\t\t\tvec2 delta_squared = delta * delta;\n");
    161     fsBuilder->codeAppend("\t\t\tweight = min(min(delta_squared.x, delta_squared.y), 1.0);\n");
    162     fsBuilder->codeAppend("\t\t}\n");
    163 
    164     fsBuilder->codeAppend("\t\tvec2 mix_coord = mix(coord, zoom_coord, weight);\n");
    165     fsBuilder->codeAppend("\t\tvec4 output_color = ");
    166     fsBuilder->appendTextureLookup(samplers[0], "mix_coord");
    167     fsBuilder->codeAppend(";\n");
    168 
    169     fsBuilder->codeAppendf("\t\t%s = output_color;", outputColor);
    170     SkString modulate;
    171     GrGLSLMulVarBy4f(&modulate, 2, outputColor, inputColor);
    172     fsBuilder->codeAppend(modulate.c_str());
    173 }
    174 
    175 void GrGLMagnifierEffect::setData(const GrGLProgramDataManager& pdman,
    176                                   const GrProcessor& effect) {
    177     const GrMagnifierEffect& zoom = effect.cast<GrMagnifierEffect>();
    178     pdman.set2f(fOffsetVar, zoom.x_offset(), zoom.y_offset());
    179     pdman.set2f(fInvZoomVar, zoom.x_inv_zoom(), zoom.y_inv_zoom());
    180     pdman.set2f(fInvInsetVar, zoom.x_inv_inset(), zoom.y_inv_inset());
    181 }
    182 
    183 /////////////////////////////////////////////////////////////////////
    184 
    185 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrMagnifierEffect);
    186 
    187 GrFragmentProcessor* GrMagnifierEffect::TestCreate(SkRandom* random,
    188                                                    GrContext* context,
    189                                                    const GrDrawTargetCaps&,
    190                                                    GrTexture** textures) {
    191     GrTexture* texture = textures[0];
    192     const int kMaxWidth = 200;
    193     const int kMaxHeight = 200;
    194     const int kMaxInset = 20;
    195     uint32_t width = random->nextULessThan(kMaxWidth);
    196     uint32_t height = random->nextULessThan(kMaxHeight);
    197     uint32_t x = random->nextULessThan(kMaxWidth - width);
    198     uint32_t y = random->nextULessThan(kMaxHeight - height);
    199     uint32_t inset = random->nextULessThan(kMaxInset);
    200 
    201     GrFragmentProcessor* effect = GrMagnifierEffect::Create(
    202         texture,
    203         (float) width / texture->width(),
    204         (float) height / texture->height(),
    205         texture->width() / (float) x,
    206         texture->height() / (float) y,
    207         (float) inset / texture->width(),
    208         (float) inset / texture->height());
    209     SkASSERT(effect);
    210     return effect;
    211 }
    212 
    213 ///////////////////////////////////////////////////////////////////////////////
    214 
    215 const GrBackendFragmentProcessorFactory& GrMagnifierEffect::getFactory() const {
    216     return GrTBackendFragmentProcessorFactory<GrMagnifierEffect>::getInstance();
    217 }
    218 
    219 bool GrMagnifierEffect::onIsEqual(const GrProcessor& sBase) const {
    220     const GrMagnifierEffect& s = sBase.cast<GrMagnifierEffect>();
    221     return (this->texture(0) == s.texture(0) &&
    222             this->fXOffset == s.fXOffset &&
    223             this->fYOffset == s.fYOffset &&
    224             this->fXInvZoom == s.fXInvZoom &&
    225             this->fYInvZoom == s.fYInvZoom &&
    226             this->fXInvInset == s.fXInvInset &&
    227             this->fYInvInset == s.fYInvInset);
    228 }
    229 
    230 void GrMagnifierEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
    231     this->updateConstantColorComponentsForModulation(color, validFlags);
    232 }
    233 
    234 #endif
    235 
    236 ////////////////////////////////////////////////////////////////////////////////
    237 
    238 SkImageFilter* SkMagnifierImageFilter::Create(const SkRect& srcRect, SkScalar inset,
    239                                               SkImageFilter* input) {
    240 
    241     if (!SkScalarIsFinite(inset) || !SkIsValidRect(srcRect)) {
    242         return NULL;
    243     }
    244     // Negative numbers in src rect are not supported
    245     if (srcRect.fLeft < 0 || srcRect.fTop < 0) {
    246         return NULL;
    247     }
    248     return SkNEW_ARGS(SkMagnifierImageFilter, (srcRect, inset, input));
    249 }
    250 
    251 
    252 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
    253 SkMagnifierImageFilter::SkMagnifierImageFilter(SkReadBuffer& buffer)
    254   : INHERITED(1, buffer) {
    255     float x = buffer.readScalar();
    256     float y = buffer.readScalar();
    257     float width = buffer.readScalar();
    258     float height = buffer.readScalar();
    259     fSrcRect = SkRect::MakeXYWH(x, y, width, height);
    260     fInset = buffer.readScalar();
    261 
    262     buffer.validate(SkScalarIsFinite(fInset) && SkIsValidRect(fSrcRect) &&
    263                     // Negative numbers in src rect are not supported
    264                     (fSrcRect.fLeft >= 0) && (fSrcRect.fTop >= 0));
    265 }
    266 #endif
    267 
    268 SkMagnifierImageFilter::SkMagnifierImageFilter(const SkRect& srcRect, SkScalar inset,
    269                                                SkImageFilter* input)
    270     : INHERITED(1, &input), fSrcRect(srcRect), fInset(inset) {
    271     SkASSERT(srcRect.x() >= 0 && srcRect.y() >= 0 && inset >= 0);
    272 }
    273 
    274 #if SK_SUPPORT_GPU
    275 bool SkMagnifierImageFilter::asFragmentProcessor(GrFragmentProcessor** fp, GrTexture* texture,
    276                                                  const SkMatrix&, const SkIRect&) const {
    277     if (fp) {
    278         SkScalar yOffset = (texture->origin() == kTopLeft_GrSurfaceOrigin) ? fSrcRect.y() :
    279                            (texture->height() - (fSrcRect.y() + fSrcRect.height()));
    280         SkScalar invInset = fInset > 0 ? SkScalarInvert(fInset) : SK_Scalar1;
    281         *fp = GrMagnifierEffect::Create(texture,
    282                                         fSrcRect.x() / texture->width(),
    283                                         yOffset / texture->height(),
    284                                         fSrcRect.width() / texture->width(),
    285                                         fSrcRect.height() / texture->height(),
    286                                         texture->width() * invInset,
    287                                         texture->height() * invInset);
    288     }
    289     return true;
    290 }
    291 #endif
    292 
    293 SkFlattenable* SkMagnifierImageFilter::CreateProc(SkReadBuffer& buffer) {
    294     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
    295     SkRect src;
    296     buffer.readRect(&src);
    297     return Create(src, buffer.readScalar(), common.getInput(0));
    298 }
    299 
    300 void SkMagnifierImageFilter::flatten(SkWriteBuffer& buffer) const {
    301     this->INHERITED::flatten(buffer);
    302     buffer.writeRect(fSrcRect);
    303     buffer.writeScalar(fInset);
    304 }
    305 
    306 bool SkMagnifierImageFilter::onFilterImage(Proxy*, const SkBitmap& src,
    307                                            const Context&, SkBitmap* dst,
    308                                            SkIPoint* offset) const {
    309     SkASSERT(src.colorType() == kN32_SkColorType);
    310     SkASSERT(fSrcRect.width() < src.width());
    311     SkASSERT(fSrcRect.height() < src.height());
    312 
    313     if ((src.colorType() != kN32_SkColorType) ||
    314         (fSrcRect.width() >= src.width()) ||
    315         (fSrcRect.height() >= src.height())) {
    316       return false;
    317     }
    318 
    319     SkAutoLockPixels alp(src);
    320     SkASSERT(src.getPixels());
    321     if (!src.getPixels() || src.width() <= 0 || src.height() <= 0) {
    322       return false;
    323     }
    324 
    325     if (!dst->tryAllocPixels(src.info())) {
    326         return false;
    327     }
    328 
    329     SkScalar inv_inset = fInset > 0 ? SkScalarInvert(fInset) : SK_Scalar1;
    330 
    331     SkScalar inv_x_zoom = fSrcRect.width() / src.width();
    332     SkScalar inv_y_zoom = fSrcRect.height() / src.height();
    333 
    334     SkColor* sptr = src.getAddr32(0, 0);
    335     SkColor* dptr = dst->getAddr32(0, 0);
    336     int width = src.width(), height = src.height();
    337     for (int y = 0; y < height; ++y) {
    338         for (int x = 0; x < width; ++x) {
    339             SkScalar x_dist = SkMin32(x, width - x - 1) * inv_inset;
    340             SkScalar y_dist = SkMin32(y, height - y - 1) * inv_inset;
    341             SkScalar weight = 0;
    342 
    343             static const SkScalar kScalar2 = SkScalar(2);
    344 
    345             // To create a smooth curve at the corners, we need to work on
    346             // a square twice the size of the inset.
    347             if (x_dist < kScalar2 && y_dist < kScalar2) {
    348                 x_dist = kScalar2 - x_dist;
    349                 y_dist = kScalar2 - y_dist;
    350 
    351                 SkScalar dist = SkScalarSqrt(SkScalarSquare(x_dist) +
    352                                              SkScalarSquare(y_dist));
    353                 dist = SkMaxScalar(kScalar2 - dist, 0);
    354                 weight = SkMinScalar(SkScalarSquare(dist), SK_Scalar1);
    355             } else {
    356                 SkScalar sqDist = SkMinScalar(SkScalarSquare(x_dist),
    357                                               SkScalarSquare(y_dist));
    358                 weight = SkMinScalar(sqDist, SK_Scalar1);
    359             }
    360 
    361             SkScalar x_interp = SkScalarMul(weight, (fSrcRect.x() + x * inv_x_zoom)) +
    362                            (SK_Scalar1 - weight) * x;
    363             SkScalar y_interp = SkScalarMul(weight, (fSrcRect.y() + y * inv_y_zoom)) +
    364                            (SK_Scalar1 - weight) * y;
    365 
    366             int x_val = SkPin32(SkScalarFloorToInt(x_interp), 0, width - 1);
    367             int y_val = SkPin32(SkScalarFloorToInt(y_interp), 0, height - 1);
    368 
    369             *dptr = sptr[y_val * width + x_val];
    370             dptr++;
    371         }
    372     }
    373     return true;
    374 }
    375