| /* |
| * Copyright 2012 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrTextureDomainEffect_DEFINED |
| #define GrTextureDomainEffect_DEFINED |
| |
| #include "GrSingleTextureEffect.h" |
| #include "gl/GrGLFragmentProcessor.h" |
| |
| class GrGLProgramBuilder; |
| class GrGLShaderBuilder; |
| class GrInvariantOutput; |
| struct SkRect; |
| |
| /** |
| * Limits a texture's lookup coordinates to a domain. Samples outside the domain are either clamped |
| * the edge of the domain or result in a vec4 of zeros (decal mode). The domain is clipped to |
| * normalized texture coords ([0,1]x[0,1] square). Bilinear filtering can cause texels outside the |
| * domain to affect the read value unless the caller considers this when calculating the domain. |
| */ |
| class GrTextureDomain { |
| public: |
| enum Mode { |
| // Ignore the texture domain rectangle. |
| kIgnore_Mode, |
| // Clamp texture coords to the domain rectangle. |
| kClamp_Mode, |
| // Treat the area outside the domain rectangle as fully transparent. |
| kDecal_Mode, |
| // Wrap texture coordinates. NOTE: filtering may not work as expected because Bilerp will |
| // read texels outside of the domain. We could perform additional texture reads and filter |
| // in the shader, but are not currently doing this for performance reasons |
| kRepeat_Mode, |
| |
| kLastMode = kRepeat_Mode |
| }; |
| static const int kModeCount = kLastMode + 1; |
| |
| static const GrTextureDomain& IgnoredDomain() { |
| static const SkRect gDummyRect = {0, 0, 0, 0}; |
| static const GrTextureDomain gDomain(gDummyRect, kIgnore_Mode); |
| return gDomain; |
| } |
| |
| /** |
| * @param index Pass a value >= 0 if using multiple texture domains in the same effect. |
| * It is used to keep inserted variables from causing name collisions. |
| */ |
| GrTextureDomain(const SkRect& domain, Mode, int index = -1); |
| |
| const SkRect& domain() const { return fDomain; } |
| Mode mode() const { return fMode; } |
| |
| /* Computes a domain that bounds all the texels in texelRect. Note that with bilerp enabled |
| texels neighboring the domain may be read. */ |
| static const SkRect MakeTexelDomain(const GrTexture* texture, const SkIRect& texelRect) { |
| SkScalar wInv = SK_Scalar1 / texture->width(); |
| SkScalar hInv = SK_Scalar1 / texture->height(); |
| SkRect result = { |
| texelRect.fLeft * wInv, |
| texelRect.fTop * hInv, |
| texelRect.fRight * wInv, |
| texelRect.fBottom * hInv |
| }; |
| return result; |
| } |
| |
| static const SkRect MakeTexelDomainForMode(const GrTexture* texture, const SkIRect& texelRect, Mode mode) { |
| // For Clamp mode, inset by half a texel. |
| SkScalar wInv = SK_Scalar1 / texture->width(); |
| SkScalar hInv = SK_Scalar1 / texture->height(); |
| SkScalar inset = (mode == kClamp_Mode && !texelRect.isEmpty()) ? SK_ScalarHalf : 0; |
| return SkRect::MakeLTRB( |
| (texelRect.fLeft + inset) * wInv, |
| (texelRect.fTop + inset) * hInv, |
| (texelRect.fRight - inset) * wInv, |
| (texelRect.fBottom - inset) * hInv |
| ); |
| } |
| |
| bool operator== (const GrTextureDomain& that) const { |
| return fMode == that.fMode && (kIgnore_Mode == fMode || fDomain == that.fDomain); |
| } |
| |
| /** |
| * A GrGLProcessor subclass that corresponds to a GrProcessor subclass that uses GrTextureDomain |
| * should include this helper. It generates the texture domain GLSL, produces the part of the |
| * effect key that reflects the texture domain code, and performs the uniform uploads necessary |
| * for texture domains. |
| */ |
| class GLDomain { |
| public: |
| GLDomain() { |
| fPrevDomain[0] = SK_FloatNaN; |
| SkDEBUGCODE(fMode = (Mode) -1;) |
| } |
| |
| /** |
| * Call this from GrGLProcessor::emitCode() to sample the texture W.R.T. the domain and |
| * mode. |
| * |
| * @param outcolor name of vec4 variable to hold the sampled color. |
| * @param inCoords name of vec2 variable containing the coords to be used with the domain. |
| * It is assumed that this is a variable and not an expression. |
| * @param inModulateColor if non-NULL the sampled color will be modulated with this |
| * expression before being written to outColor. |
| */ |
| void sampleTexture(GrGLShaderBuilder* builder, |
| const GrTextureDomain& textureDomain, |
| const char* outColor, |
| const SkString& inCoords, |
| const GrGLProcessor::TextureSampler sampler, |
| const char* inModulateColor = NULL); |
| |
| /** |
| * Call this from GrGLProcessor::setData() to upload uniforms necessary for the texture |
| * domain. The rectangle is automatically adjusted to account for the texture's origin. |
| */ |
| void setData(const GrGLProgramDataManager& pdman, const GrTextureDomain& textureDomain, |
| GrSurfaceOrigin textureOrigin); |
| |
| enum { |
| kDomainKeyBits = 2, // See DomainKey(). |
| }; |
| |
| /** |
| * GrGLProcessor::GenKey() must call this and include the returned value in it's computed |
| * key. The returned will be limited to the lower kDomainKeyBits bits. |
| */ |
| static uint32_t DomainKey(const GrTextureDomain& domain) { |
| GR_STATIC_ASSERT(kModeCount <= 4); |
| return domain.mode(); |
| } |
| |
| private: |
| SkDEBUGCODE(Mode fMode;) |
| GrGLProgramDataManager::UniformHandle fDomainUni; |
| SkString fDomainName; |
| GrGLfloat fPrevDomain[4]; |
| }; |
| |
| protected: |
| Mode fMode; |
| SkRect fDomain; |
| int fIndex; |
| |
| typedef GrSingleTextureEffect INHERITED; |
| }; |
| |
| /** |
| * A basic texture effect that uses GrTextureDomain. |
| */ |
| class GrTextureDomainEffect : public GrSingleTextureEffect { |
| |
| public: |
| static GrFragmentProcessor* Create(GrProcessorDataManager*, |
| GrTexture*, |
| const SkMatrix&, |
| const SkRect& domain, |
| GrTextureDomain::Mode, |
| GrTextureParams::FilterMode filterMode, |
| GrCoordSet = kLocal_GrCoordSet); |
| |
| virtual ~GrTextureDomainEffect(); |
| |
| const char* name() const override { return "TextureDomain"; } |
| |
| const GrTextureDomain& textureDomain() const { return fTextureDomain; } |
| |
| protected: |
| GrTextureDomain fTextureDomain; |
| |
| private: |
| GrTextureDomainEffect(GrProcessorDataManager*, |
| GrTexture*, |
| const SkMatrix&, |
| const SkRect& domain, |
| GrTextureDomain::Mode, |
| GrTextureParams::FilterMode, |
| GrCoordSet); |
| |
| GrGLFragmentProcessor* onCreateGLInstance() const override; |
| |
| void onGetGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override; |
| |
| bool onIsEqual(const GrFragmentProcessor&) const override; |
| |
| void onComputeInvariantOutput(GrInvariantOutput* inout) const override; |
| |
| GR_DECLARE_FRAGMENT_PROCESSOR_TEST; |
| |
| typedef GrSingleTextureEffect INHERITED; |
| }; |
| |
| #endif |