src/gpu/effects/GrSimpleTextureEffect.h

/*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef GrSimpleTextureEffect_DEFINED
#define GrSimpleTextureEffect_DEFINED

#include "GrSingleTextureEffect.h"
#include "GrTextureProxy.h"

class GrInvariantOutput;

// In a few places below we rely on braced initialization order being defined by the C++ spec (left
// to right). We use operator-> on a sk_sp and then in a later argument std::move() the sk_sp. GCC
// 4.9.0 and earlier has a bug where the left to right order evaluation isn't implemented correctly.
#if defined(__GNUC__) && !defined(__clang__)
#   define GCC_VERSION (__GNUC__ * 10000  + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
#   if (GCC_VERSION > 40900)
#       define GCC_EVAL_ORDER_BUG 0
#   else
#       define GCC_EVAL_ORDER_BUG 1
#   endif
#   undef GCC_VERSION
#else
#   define GCC_EVAL_ORDER_BUG 0
#endif

#if GCC_EVAL_ORDER_BUG
#   define PROXY_MOVE(X) (X)
#else
#   define PROXY_MOVE(X) (std::move(X))
#endif

#undef GCC_EVAL_ORDER_BUG

/**
 * The output color of this effect is a modulation of the input color and a sample from a texture.
 * It allows explicit specification of the filtering and wrap modes (GrSamplerParams) and accepts
 * a matrix that is used to compute texture coordinates from local coordinates.
 */
class GrSimpleTextureEffect : public GrSingleTextureEffect {
public:
    /* unfiltered, clamp mode */
    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex,
                                           sk_sp<GrColorSpaceXform> colorSpaceXform,
                                           const SkMatrix& matrix) {
        return sk_sp<GrFragmentProcessor>(
            new GrSimpleTextureEffect(tex, std::move(colorSpaceXform), matrix,
                                      GrSamplerParams::kNone_FilterMode));
    }

    static sk_sp<GrFragmentProcessor> Make(GrContext* ctx, sk_sp<GrTextureProxy> proxy,
                                           sk_sp<GrColorSpaceXform> colorSpaceXform,
                                           const SkMatrix& matrix) {
        return sk_sp<GrFragmentProcessor>(
            new GrSimpleTextureEffect(ctx, std::move(proxy), std::move(colorSpaceXform), matrix,
                                      GrSamplerParams::kNone_FilterMode));
    }

    /* clamp mode */
    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex,
                                           sk_sp<GrColorSpaceXform> colorSpaceXform,
                                           const SkMatrix& matrix,
                                           GrSamplerParams::FilterMode filterMode) {
        return sk_sp<GrFragmentProcessor>(
            new GrSimpleTextureEffect(tex, std::move(colorSpaceXform), matrix, filterMode));
    }

    static sk_sp<GrFragmentProcessor> Make(GrContext* ctx, sk_sp<GrTextureProxy> proxy,
                                           sk_sp<GrColorSpaceXform> colorSpaceXform,
                                           const SkMatrix& matrix,
                                           GrSamplerParams::FilterMode filterMode) {
        return sk_sp<GrFragmentProcessor>(
            new GrSimpleTextureEffect(ctx, std::move(proxy), std::move(colorSpaceXform),
                                      matrix, filterMode));
    }

    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex,
                                           sk_sp<GrColorSpaceXform> colorSpaceXform,
                                           const SkMatrix& matrix,
                                           const GrSamplerParams& p) {
        return sk_sp<GrFragmentProcessor>(new GrSimpleTextureEffect(tex, std::move(colorSpaceXform),
                                                                    matrix, p));
    }

    static sk_sp<GrFragmentProcessor> Make(GrContext* ctx, sk_sp<GrTextureProxy> proxy,
                                           sk_sp<GrColorSpaceXform> colorSpaceXform,
                                           const SkMatrix& matrix,
                                           const GrSamplerParams& p) {
        return sk_sp<GrFragmentProcessor>(new GrSimpleTextureEffect(ctx, std::move(proxy),
                                                                    std::move(colorSpaceXform),
                                                                    matrix, p));
    }

    virtual ~GrSimpleTextureEffect() {}

    const char* name() const override { return "SimpleTexture"; }

private:
    GrSimpleTextureEffect(GrTexture* texture,
                          sk_sp<GrColorSpaceXform> colorSpaceXform,
                          const SkMatrix& matrix,
                          GrSamplerParams::FilterMode filterMode)
            : INHERITED(texture, std::move(colorSpaceXform), matrix, filterMode,
                        ModulationFlags(texture->config())) {
        this->initClassID<GrSimpleTextureEffect>();
    }

    GrSimpleTextureEffect(GrContext* ctx, sk_sp<GrTextureProxy> proxy,
                          sk_sp<GrColorSpaceXform> colorSpaceXform, const SkMatrix& matrix,
                          GrSamplerParams::FilterMode filterMode)
            : INHERITED{ctx,
                        ModulationFlags(proxy->config()),
                        PROXY_MOVE(proxy),
                        std::move(colorSpaceXform),
                        matrix,
                        filterMode} {
        this->initClassID<GrSimpleTextureEffect>();
    }

    GrSimpleTextureEffect(GrTexture* texture,
                          sk_sp<GrColorSpaceXform>colorSpaceXform,
                          const SkMatrix& matrix,
                          const GrSamplerParams& params)
            : INHERITED(texture, std::move(colorSpaceXform), matrix, params,
                        ModulationFlags(texture->config())) {
        this->initClassID<GrSimpleTextureEffect>();
    }

    GrSimpleTextureEffect(GrContext* ctx, sk_sp<GrTextureProxy> proxy,
                          sk_sp<GrColorSpaceXform> colorSpaceXform, const SkMatrix& matrix,
                          const GrSamplerParams& params)
            : INHERITED{ctx,
                        ModulationFlags(proxy->config()),
                        PROXY_MOVE(proxy),
                        std::move(colorSpaceXform),
                        matrix,
                        params} {
        this->initClassID<GrSimpleTextureEffect>();
    }

    GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;

    void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override;

    bool onIsEqual(const GrFragmentProcessor& other) const override { return true; }

    void onComputeInvariantOutput(GrInvariantOutput* inout) const override;

    GR_DECLARE_FRAGMENT_PROCESSOR_TEST;

    typedef GrSingleTextureEffect INHERITED;
};

#undef PROXY_MOVE

#endif