/*

 * Copyright 2016 Google Inc.

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#include "src/gpu/ganesh/GrProgramDesc.h"

#include "include/gpu/ganesh/GrBackendSurface.h"

#include "include/private/base/SkAssert.h"

#include "include/private/base/SkTo.h"

#include "include/private/gpu/ganesh/GrTypesPriv.h"

#include "src/gpu/KeyBuilder.h"

#include "src/gpu/Swizzle.h"

#include "src/gpu/ganesh/GrCaps.h"

#include "src/gpu/ganesh/GrFragmentProcessor.h"

#include "src/gpu/ganesh/GrGeometryProcessor.h"

#include "src/gpu/ganesh/GrPipeline.h"

#include "src/gpu/ganesh/GrProcessor.h"

#include "src/gpu/ganesh/GrProgramInfo.h"

#include "src/gpu/ganesh/GrSurfaceProxy.h"

#include "src/gpu/ganesh/GrSurfaceProxyView.h"

#include "src/gpu/ganesh/GrXferProcessor.h"

#include "src/gpu/ganesh/effects/GrTextureEffect.h"

enum GrSurfaceOrigin : int;

// Currently we allow 8 bits for the class id

static constexpr uint32_t kClassIDBits = 8;

static constexpr uint32_t kSamplerOrImageTypeKeyBits = 4;

static inline uint16_t texture_type_key(GrTextureType type) {

    int value = UINT16_MAX;

    switch (type) {

        case GrTextureType::k2D:

            value = 0;

            break;

        case GrTextureType::kExternal:

            value = 1;

            break;

        case GrTextureType::kRectangle:

            value = 2;

            break;

        default:

            SK_ABORT("Unexpected texture type");

            value = 3;

            break;

    }

    SkASSERT((value & ((1 << kSamplerOrImageTypeKeyBits) - 1)) == value);

    return SkToU16(value);

}

Unexecuted instantiation: GrProgramDesc.cpp:texture_type_key(GrTextureType)

Unexecuted instantiation: GrProgramDesc.cpp:texture_type_key(GrTextureType)

static uint32_t sampler_key(GrTextureType textureType, const skgpu::Swizzle& swizzle,

                            const GrCaps& caps) {

    int samplerTypeKey = texture_type_key(textureType);

    static_assert(2 == sizeof(swizzle.asKey()));

    uint16_t swizzleKey = swizzle.asKey();

    return SkToU32(samplerTypeKey | swizzleKey << kSamplerOrImageTypeKeyBits);

}

static void add_geomproc_sampler_keys(skgpu::KeyBuilder* b,

                                      const GrGeometryProcessor& geomProc,

                                      const GrCaps& caps) {

    int numTextureSamplers = geomProc.numTextureSamplers();

    b->add32(numTextureSamplers, "ppNumSamplers");

    for (int i = 0; i < numTextureSamplers; ++i) {

        const GrGeometryProcessor::TextureSampler& sampler = geomProc.textureSampler(i);

        const GrBackendFormat& backendFormat = sampler.backendFormat();

        uint32_t samplerKey = sampler_key(backendFormat.textureType(), sampler.swizzle(), caps);

        b->add32(samplerKey);

        caps.addExtraSamplerKey(b, sampler.samplerState(), backendFormat);

    }

}

/**

 * Functions which emit processor key info into the key builder.

 * For every effect, we include the effect's class ID (different for every GrProcessor subclass),

 * any information generated by the effect itself (addToKey), and some meta-information.

 * Shader code may be dependent on properties of the effect not placed in the key by the effect

 * (e.g. pixel format of textures used).

 */

static void gen_geomproc_key(const GrGeometryProcessor& geomProc,

                             const GrCaps& caps,

                             skgpu::KeyBuilder* b) {

    b->appendComment(geomProc.name());

    b->addBits(kClassIDBits, geomProc.classID(), "geomProcClassID");

    geomProc.addToKey(*caps.shaderCaps(), b);

    geomProc.getAttributeKey(b);

    add_geomproc_sampler_keys(b, geomProc, caps);

}

static void gen_xp_key(const GrXferProcessor& xp,

                       const GrCaps& caps,

                       const GrPipeline& pipeline,

                       skgpu::KeyBuilder* b) {

    b->appendComment(xp.name());

    b->addBits(kClassIDBits, xp.classID(), "xpClassID");

    const GrSurfaceOrigin* originIfDstTexture = nullptr;

    GrSurfaceOrigin origin;

    const GrSurfaceProxyView& dstView = pipeline.dstProxyView();

    if (dstView.proxy()) {

        origin = dstView.origin();

        originIfDstTexture = &origin;

        uint32_t samplerKey = sampler_key(dstView.proxy()->backendFormat().textureType(),

                                          dstView.swizzle(), caps);

        b->add32(samplerKey);

    }

    xp.addToKey(*caps.shaderCaps(),

                b,

                originIfDstTexture,

                pipeline.dstSampleFlags() & GrDstSampleFlags::kAsInputAttachment);

}

static void gen_fp_key(const GrFragmentProcessor& fp,

                       const GrCaps& caps,

                       skgpu::KeyBuilder* b) {

    b->appendComment(fp.name());

    b->addBits(kClassIDBits, fp.classID(), "fpClassID");

    b->addBits(GrGeometryProcessor::kCoordTransformKeyBits,

               GrGeometryProcessor::ComputeCoordTransformsKey(fp), "fpTransforms");

    if (auto* te = fp.asTextureEffect()) {

        const GrBackendFormat& backendFormat = te->view().proxy()->backendFormat();

        uint32_t samplerKey = sampler_key(backendFormat.textureType(), te->view().swizzle(), caps);

        b->add32(samplerKey, "fpSamplerKey");

        caps.addExtraSamplerKey(b, te->samplerState(), backendFormat);

    }

    fp.addToKey(*caps.shaderCaps(), b);

    b->add32(fp.numChildProcessors(), "fpNumChildren");

    for (int i = 0; i < fp.numChildProcessors(); ++i) {

        if (auto child = fp.childProcessor(i)) {

            gen_fp_key(*child, caps, b);

        } else {

            // Fold in a sentinel value as the "class ID" for any null children

            b->appendComment("Null");

            b->addBits(kClassIDBits, GrProcessor::ClassID::kNull_ClassID, "fpClassID");

        }

    }

}

static void gen_key(skgpu::KeyBuilder* b,

                    const GrProgramInfo& programInfo,

                    const GrCaps& caps) {

    gen_geomproc_key(programInfo.geomProc(), caps, b);

    const GrPipeline& pipeline = programInfo.pipeline();

    b->addBits(2, pipeline.numFragmentProcessors(),      "numFPs");

    b->addBits(1, pipeline.numColorFragmentProcessors(), "numColorFPs");

    for (int i = 0; i < pipeline.numFragmentProcessors(); ++i) {

        gen_fp_key(pipeline.getFragmentProcessor(i), caps, b);

    }

    gen_xp_key(pipeline.getXferProcessor(), caps, pipeline, b);

    b->addBits(16, pipeline.writeSwizzle().asKey(), "writeSwizzle");

    b->addBool(pipeline.snapVerticesToPixelCenters(), "snapVertices");

    // The base descriptor only stores whether or not the primitiveType is kPoints. Backend-

    // specific versions (e.g., Vulkan) require more detail

    b->addBool((programInfo.primitiveType() == GrPrimitiveType::kPoints), "isPoints");

    // Put a clean break between the "common" data written by this function, and any backend data

    // appended later. The initial key length will just be this portion (rounded to 4 bytes).

    b->flush();

}

void GrProgramDesc::Build(GrProgramDesc* desc,

                          const GrProgramInfo& programInfo,

                          const GrCaps& caps) {

    desc->reset();

    skgpu::KeyBuilder b(desc->key());

    gen_key(&b, programInfo, caps);

    desc->fInitialKeyLength = desc->keyLength();

}

SkString GrProgramDesc::Describe(const GrProgramInfo& programInfo,

                                 const GrCaps& caps) {

    GrProgramDesc desc;

    skgpu::StringKeyBuilder b(desc.key());

    gen_key(&b, programInfo, caps);

    b.flush();

    return b.description();

}