Make texture domain a helper so that it can be incorporated into other effects.

R=robertphillips@google.com, jvanverth@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/98893006

git-svn-id: http://skia.googlecode.com/svn/trunk@12569 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 280 insertions, 0 deletions

diff --git a/src/gpu/effects/GrTextureDomain.cpp b/src/gpu/effects/GrTextureDomain.cpp
new file mode 100644
index 0000000000..517eb6dce1
--- /dev/null
+++ b/src/gpu/effects/GrTextureDomain.cpp
@@ -0,0 +1,280 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrTextureDomain.h"
+#include "GrSimpleTextureEffect.h"
+#include "GrTBackendEffectFactory.h"
+#include "gl/GrGLEffect.h"
+#include "SkFloatingPoint.h"
+
+
+GrTextureDomain::GrTextureDomain(const SkRect& domain, Mode mode, int index)
+    : fIndex(index) {
+
+    static const SkRect kFullRect = {0, 0, SK_Scalar1, SK_Scalar1};
+    if (domain.contains(kFullRect)) {
+        fMode = kIgnore_Mode;
+    } else {
+        fMode = mode;
+    }
+
+    if (fMode != kIgnore_Mode) {
+        // We don't currently handle domains that are empty or don't intersect the texture.
+        // It is OK if the domain rect is a line or point, but it should not be inverted. We do not
+        // handle rects that do not intersect the [0..1]x[0..1] rect.
+        SkASSERT(domain.fLeft <= domain.fRight);
+        SkASSERT(domain.fTop <= domain.fBottom);
+        fDomain.fLeft = SkMaxScalar(domain.fLeft, kFullRect.fLeft);
+        fDomain.fRight = SkMinScalar(domain.fRight, kFullRect.fRight);
+        fDomain.fTop = SkMaxScalar(domain.fTop, kFullRect.fTop);
+        fDomain.fBottom = SkMinScalar(domain.fBottom, kFullRect.fBottom);
+        SkASSERT(fDomain.fLeft <= fDomain.fRight);
+        SkASSERT(fDomain.fTop <= fDomain.fBottom);
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+void GrTextureDomain::GLDomain::sampleTexture(GrGLShaderBuilder* builder,
+                                              const GrTextureDomain& textureDomain,
+                                              const char* outColor,
+                                              const SkString& inCoords,
+                                              const GrGLEffect::TextureSampler sampler,
+                                              const char* inModulateColor) {
+    SkASSERT(-1 == fMode || textureDomain.mode() == fMode);
+    SkDEBUGCODE(fMode = textureDomain.mode();)
+
+    if (kIgnore_Mode == textureDomain.mode()) {
+        builder->fsCodeAppendf("\t%s = ", outColor);
+        builder->fsAppendTextureLookupAndModulate(inModulateColor, sampler,
+                                                    inCoords.c_str());
+        builder->fsCodeAppend(";\n");
+        return;
+    }
+
+    if (!fDomainUni.isValid()) {
+        const char* name;
+        SkString uniName("TexDom");
+        if (textureDomain.fIndex >= 0) {
+            uniName.appendS32(textureDomain.fIndex);
+        }
+        fDomainUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
+                                            kVec4f_GrSLType, uniName.c_str(), &name);
+        fDomainName = name;
+    }
+    if (kClamp_Mode == textureDomain.mode()) {
+        SkString clampedCoords;
+        clampedCoords.appendf("\tclamp(%s, %s.xy, %s.zw)",
+                                inCoords.c_str(), fDomainName.c_str(), fDomainName.c_str());
+
+        builder->fsCodeAppendf("\t%s = ", outColor);
+        builder->fsAppendTextureLookupAndModulate(inModulateColor, sampler, clampedCoords.c_str());
+        builder->fsCodeAppend(";\n");
+    } else {
+        SkASSERT(GrTextureDomain::kDecal_Mode == textureDomain.mode());
+        // Add a block since we're going to declare variables.
+        GrGLShaderBuilder::FSBlock block(builder);
+
+        const char* domain = fDomainName.c_str();
+        if (kImagination_GrGLVendor == builder->ctxInfo().vendor()) {
+            // On the NexusS and GalaxyNexus, the other path (with the 'any'
+            // call) causes the compilation error "Calls to any function that
+            // may require a gradient calculation inside a conditional block
+            // may return undefined results". This appears to be an issue with
+            // the 'any' call since even the simple "result=black; if (any())
+            // result=white;" code fails to compile.
+            builder->fsCodeAppend("\tvec4 outside = vec4(0.0, 0.0, 0.0, 0.0);\n");
+            builder->fsCodeAppend("\tvec4 inside = ");
+            builder->fsAppendTextureLookupAndModulate(inModulateColor, sampler, inCoords.c_str());
+            builder->fsCodeAppend(";\n");
+
+            builder->fsCodeAppendf("\tfloat x = abs(2.0*(%s.x - %s.x)/(%s.z - %s.x) - 1.0);\n",
+                                    inCoords.c_str(), domain, domain, domain);
+            builder->fsCodeAppendf("\tfloat y = abs(2.0*(%s.y - %s.y)/(%s.w - %s.y) - 1.0);\n",
+                                    inCoords.c_str(), domain, domain, domain);
+            builder->fsCodeAppend("\tfloat blend = step(1.0, max(x, y));\n");
+            builder->fsCodeAppendf("\t%s = mix(inside, outside, blend);\n", outColor);
+        } else {
+            builder->fsCodeAppend("\tbvec4 outside;\n");
+            builder->fsCodeAppendf("\toutside.xy = lessThan(%s, %s.xy);\n", inCoords.c_str(),
+                                   domain);
+            builder->fsCodeAppendf("\toutside.zw = greaterThan(%s, %s.zw);\n", inCoords.c_str(),
+                                   domain);
+            builder->fsCodeAppendf("\t%s = any(outside) ? vec4(0.0, 0.0, 0.0, 0.0) : ", outColor);
+            builder->fsAppendTextureLookupAndModulate(inModulateColor, sampler, inCoords.c_str());
+            builder->fsCodeAppend(";\n");
+        }
+    }
+}
+
+void GrTextureDomain::GLDomain::setData(const GrGLUniformManager& uman,
+                                        const GrTextureDomain& textureDomain,
+                                        GrSurfaceOrigin textureOrigin) {
+    SkASSERT(textureDomain.mode() == fMode);
+    if (kIgnore_Mode != textureDomain.mode()) {
+        GrGLfloat values[4] = {
+            SkScalarToFloat(textureDomain.domain().left()),
+            SkScalarToFloat(textureDomain.domain().top()),
+            SkScalarToFloat(textureDomain.domain().right()),
+            SkScalarToFloat(textureDomain.domain().bottom())
+        };
+        // vertical flip if necessary
+        if (kBottomLeft_GrSurfaceOrigin == textureOrigin) {
+            values[1] = 1.0f - values[1];
+            values[3] = 1.0f - values[3];
+            // The top and bottom were just flipped, so correct the ordering
+            // of elements so that values = (l, t, r, b).
+            SkTSwap(values[1], values[3]);
+        }
+        if (0 != memcmp(values, fPrevDomain, 4 * sizeof(GrGLfloat))) {
+            uman.set4fv(fDomainUni, 1, values);
+            memcpy(fPrevDomain, values, 4 * sizeof(GrGLfloat));
+        }
+    }
+}
+
+
+//////////////////////////////////////////////////////////////////////////////
+
+class GrGLTextureDomainEffect : public GrGLEffect {
+public:
+    GrGLTextureDomainEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
+
+    virtual void emitCode(GrGLShaderBuilder*,
+                          const GrDrawEffect&,
+                          EffectKey,
+                          const char* outputColor,
+                          const char* inputColor,
+                          const TransformedCoordsArray&,
+                          const TextureSamplerArray&) SK_OVERRIDE;
+
+    virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
+
+    static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
+
+private:
+    GrTextureDomain::GLDomain         fGLDomain;
+    typedef GrGLEffect INHERITED;
+};
+
+GrGLTextureDomainEffect::GrGLTextureDomainEffect(const GrBackendEffectFactory& factory,
+                                                 const GrDrawEffect&)
+    : INHERITED(factory) {
+}
+
+void GrGLTextureDomainEffect::emitCode(GrGLShaderBuilder* builder,
+                                       const GrDrawEffect& drawEffect,
+                                       EffectKey key,
+                                       const char* outputColor,
+                                       const char* inputColor,
+                                       const TransformedCoordsArray& coords,
+                                       const TextureSamplerArray& samplers) {
+    const GrTextureDomainEffect& effect = drawEffect.castEffect<GrTextureDomainEffect>();
+    const GrTextureDomain& domain = effect.textureDomain();
+
+    SkString coords2D = builder->ensureFSCoords2D(coords, 0);
+    fGLDomain.sampleTexture(builder, domain, outputColor, coords2D, samplers[0], inputColor);
+}
+
+void GrGLTextureDomainEffect::setData(const GrGLUniformManager& uman,
+                                      const GrDrawEffect& drawEffect) {
+    const GrTextureDomainEffect& effect = drawEffect.castEffect<GrTextureDomainEffect>();
+    const GrTextureDomain& domain = effect.textureDomain();
+    fGLDomain.setData(uman, domain, effect.texture(0)->origin());
+}
+
+GrGLEffect::EffectKey GrGLTextureDomainEffect::GenKey(const GrDrawEffect& drawEffect,
+                                                      const GrGLCaps&) {
+    const GrTextureDomain& domain = drawEffect.castEffect<GrTextureDomainEffect>().textureDomain();
+    return GrTextureDomain::GLDomain::DomainKey(domain);
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+
+GrEffectRef* GrTextureDomainEffect::Create(GrTexture* texture,
+                                           const SkMatrix& matrix,
+                                           const SkRect& domain,
+                                           GrTextureDomain::Mode mode,
+                                           GrTextureParams::FilterMode filterMode,
+                                           GrCoordSet coordSet) {
+    static const SkRect kFullRect = {0, 0, SK_Scalar1, SK_Scalar1};
+    if (GrTextureDomain::kIgnore_Mode == mode ||
+        (GrTextureDomain::kClamp_Mode == mode && domain.contains(kFullRect))) {
+        return GrSimpleTextureEffect::Create(texture, matrix, filterMode);
+    } else {
+
+        AutoEffectUnref effect(SkNEW_ARGS(GrTextureDomainEffect, (texture,
+                                                                  matrix,
+                                                                  domain,
+                                                                  mode,
+                                                                  filterMode,
+                                                                  coordSet)));
+        return CreateEffectRef(effect);
+
+    }
+}
+
+GrTextureDomainEffect::GrTextureDomainEffect(GrTexture* texture,
+                                             const SkMatrix& matrix,
+                                             const SkRect& domain,
+                                             GrTextureDomain::Mode mode,
+                                             GrTextureParams::FilterMode filterMode,
+                                             GrCoordSet coordSet)
+    : GrSingleTextureEffect(texture, matrix, filterMode, coordSet)
+    , fTextureDomain(domain, mode) {
+}
+
+GrTextureDomainEffect::~GrTextureDomainEffect() {
+
+}
+
+const GrBackendEffectFactory& GrTextureDomainEffect::getFactory() const {
+    return GrTBackendEffectFactory<GrTextureDomainEffect>::getInstance();
+}
+
+bool GrTextureDomainEffect::onIsEqual(const GrEffect& sBase) const {
+    const GrTextureDomainEffect& s = CastEffect<GrTextureDomainEffect>(sBase);
+    return this->hasSameTextureParamsMatrixAndSourceCoords(s) &&
+           this->fTextureDomain == s.fTextureDomain;
+}
+
+void GrTextureDomainEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
+    if (GrTextureDomain::kDecal_Mode == fTextureDomain.mode()) { // TODO: helper
+        *validFlags = 0;
+    } else {
+        this->updateConstantColorComponentsForModulation(color, validFlags);
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+GR_DEFINE_EFFECT_TEST(GrTextureDomainEffect);
+
+GrEffectRef* GrTextureDomainEffect::TestCreate(SkRandom* random,
+                                               GrContext*,
+                                               const GrDrawTargetCaps&,
+                                               GrTexture* textures[]) {
+    int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx :
+                                      GrEffectUnitTest::kAlphaTextureIdx;
+    SkRect domain;
+    domain.fLeft = random->nextUScalar1();
+    domain.fRight = random->nextRangeScalar(domain.fLeft, SK_Scalar1);
+    domain.fTop = random->nextUScalar1();
+    domain.fBottom = random->nextRangeScalar(domain.fTop, SK_Scalar1);
+    GrTextureDomain::Mode mode =
+        (GrTextureDomain::Mode) random->nextULessThan(GrTextureDomain::kModeCount);
+    const SkMatrix& matrix = GrEffectUnitTest::TestMatrix(random);
+    bool bilerp = random->nextBool();
+    GrCoordSet coords = random->nextBool() ? kLocal_GrCoordSet : kPosition_GrCoordSet;
+    return GrTextureDomainEffect::Create(textures[texIdx],
+                                         matrix,
+                                         domain,
+                                         mode,
+                                         bilerp ? GrTextureParams::kBilerp_FilterMode : GrTextureParams::kNone_FilterMode,
+                                         coords);
+}