1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/gpu/effects/GrTextureDomain.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,175 @@
1.4 +/*
1.5 + * Copyright 2012 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef GrTextureDomainEffect_DEFINED
1.12 +#define GrTextureDomainEffect_DEFINED
1.13 +
1.14 +#include "GrSingleTextureEffect.h"
1.15 +#include "gl/GrGLEffect.h"
1.16 +
1.17 +class GrGLShaderBuilder;
1.18 +struct SkRect;
1.19 +
1.20 +/**
1.21 + * Limits a texture's lookup coordinates to a domain. Samples outside the domain are either clamped
1.22 + * the edge of the domain or result in a vec4 of zeros (decal mode). The domain is clipped to
1.23 + * normalized texture coords ([0,1]x[0,1] square). Bilinear filtering can cause texels outside the
1.24 + * domain to affect the read value unless the caller considers this when calculating the domain.
1.25 + */
1.26 +class GrTextureDomain {
1.27 +public:
1.28 + enum Mode {
1.29 + kIgnore_Mode, // Ignore the texture domain rectangle.
1.30 + kClamp_Mode, // Clamp texture coords to the domain rectangle.
1.31 + kDecal_Mode, // Treat the area outside the domain rectangle as fully transparent.
1.32 +
1.33 + kLastMode = kDecal_Mode
1.34 + };
1.35 + static const int kModeCount = kLastMode + 1;
1.36 +
1.37 + static const GrTextureDomain& IgnoredDomain() {
1.38 + static const SkRect gDummyRect = {0, 0, 0, 0};
1.39 + static const GrTextureDomain gDomain(gDummyRect, kIgnore_Mode);
1.40 + return gDomain;
1.41 + }
1.42 +
1.43 + /**
1.44 + * @param index Pass a value >= 0 if using multiple texture domains in the same effect.
1.45 + * It is used to keep inserted variables from causing name collisions.
1.46 + */
1.47 + GrTextureDomain(const SkRect& domain, Mode, int index = -1);
1.48 +
1.49 + const SkRect& domain() const { return fDomain; }
1.50 + Mode mode() const { return fMode; }
1.51 +
1.52 + /* Computes a domain that bounds all the texels in texelRect. Note that with bilerp enabled
1.53 + texels neighboring the domain may be read. */
1.54 + static const SkRect MakeTexelDomain(const GrTexture* texture, const SkIRect& texelRect) {
1.55 + SkScalar wInv = SK_Scalar1 / texture->width();
1.56 + SkScalar hInv = SK_Scalar1 / texture->height();
1.57 + SkRect result = {
1.58 + texelRect.fLeft * wInv,
1.59 + texelRect.fTop * hInv,
1.60 + texelRect.fRight * wInv,
1.61 + texelRect.fBottom * hInv
1.62 + };
1.63 + return result;
1.64 + }
1.65 +
1.66 + bool operator== (const GrTextureDomain& that) const {
1.67 + return fMode == that.fMode && fDomain == that.fDomain;
1.68 + }
1.69 +
1.70 + /**
1.71 + * A GrGLEffect subclass that corresponds to a GrEffect subclass that uses GrTextureDomain
1.72 + * should include this helper. It generates the texture domain GLSL, produces the part of the
1.73 + * effect key that reflects the texture domain code, and performs the uniform uploads necessary
1.74 + * for texture domains.
1.75 + */
1.76 + class GLDomain {
1.77 + public:
1.78 + GLDomain() {
1.79 + fPrevDomain[0] = SK_FloatNaN;
1.80 + SkDEBUGCODE(fMode = (Mode) -1;)
1.81 + }
1.82 +
1.83 + /**
1.84 + * Call this from GrGLEffect::emitCode() to sample the texture W.R.T. the domain and mode.
1.85 + *
1.86 + * @param outcolor name of vec4 variable to hold the sampled color.
1.87 + * @param inCoords name of vec2 variable containing the coords to be used with the domain.
1.88 + * It is assumed that this is a variable and not an expression.
1.89 + * @param inModulateColor if non-NULL the sampled color will be modulated with this
1.90 + * expression before being written to outColor.
1.91 + */
1.92 + void sampleTexture(GrGLShaderBuilder* builder,
1.93 + const GrTextureDomain& textureDomain,
1.94 + const char* outColor,
1.95 + const SkString& inCoords,
1.96 + const GrGLEffect::TextureSampler sampler,
1.97 + const char* inModulateColor = NULL);
1.98 +
1.99 + /**
1.100 + * Call this from GrGLEffect::setData() to upload uniforms necessary for the texture domain.
1.101 + * The rectangle is automatically adjusted to account for the texture's origin.
1.102 + */
1.103 + void setData(const GrGLUniformManager& uman, const GrTextureDomain& textureDomain,
1.104 + GrSurfaceOrigin textureOrigin);
1.105 +
1.106 + enum {
1.107 + kDomainKeyBits = 2, // See DomainKey().
1.108 + };
1.109 +
1.110 + /**
1.111 + * GrGLEffect::GenKey() must call this and include the returned value in it's computed key.
1.112 + * The returned will be limited to the lower kDomainKeyBits bits.
1.113 + */
1.114 + static GrGLEffect::EffectKey DomainKey(const GrTextureDomain& domain) {
1.115 + GR_STATIC_ASSERT(kModeCount <= 4);
1.116 + return domain.mode();
1.117 + }
1.118 +
1.119 + private:
1.120 + SkDEBUGCODE(Mode fMode;)
1.121 + GrGLUniformManager::UniformHandle fDomainUni;
1.122 + SkString fDomainName;
1.123 + GrGLfloat fPrevDomain[4];
1.124 + };
1.125 +
1.126 +protected:
1.127 + Mode fMode;
1.128 + SkRect fDomain;
1.129 + int fIndex;
1.130 +
1.131 + typedef GrSingleTextureEffect INHERITED;
1.132 +};
1.133 +
1.134 +class GrGLTextureDomainEffect;
1.135 +
1.136 +/**
1.137 + * A basic texture effect that uses GrTextureDomain.
1.138 + */
1.139 +class GrTextureDomainEffect : public GrSingleTextureEffect {
1.140 +
1.141 +public:
1.142 + static GrEffectRef* Create(GrTexture*,
1.143 + const SkMatrix&,
1.144 + const SkRect& domain,
1.145 + GrTextureDomain::Mode,
1.146 + GrTextureParams::FilterMode filterMode,
1.147 + GrCoordSet = kLocal_GrCoordSet);
1.148 +
1.149 + virtual ~GrTextureDomainEffect();
1.150 +
1.151 + static const char* Name() { return "TextureDomain"; }
1.152 +
1.153 + typedef GrGLTextureDomainEffect GLEffect;
1.154 +
1.155 + virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
1.156 + virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
1.157 +
1.158 + const GrTextureDomain& textureDomain() const { return fTextureDomain; }
1.159 +
1.160 +protected:
1.161 + GrTextureDomain fTextureDomain;
1.162 +
1.163 +private:
1.164 + GrTextureDomainEffect(GrTexture*,
1.165 + const SkMatrix&,
1.166 + const SkRect& domain,
1.167 + GrTextureDomain::Mode,
1.168 + GrTextureParams::FilterMode,
1.169 + GrCoordSet);
1.170 +
1.171 + virtual bool onIsEqual(const GrEffect&) const SK_OVERRIDE;
1.172 +
1.173 + GR_DECLARE_EFFECT_TEST;
1.174 +
1.175 + typedef GrSingleTextureEffect INHERITED;
1.176 +};
1.177 +
1.178 +#endif
