src/effects/SkMagnifierImageFilter.cpp

   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 }