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