/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "GrResourceProvider.h"

#include "GrGpu.h"
#include "GrResourceCache.h"
#include "GrResourceKey.h"
#include "GrVertexBuffer.h"

GR_DECLARE_STATIC_UNIQUE_KEY(gQuadIndexBufferKey);

GrResourceProvider::GrResourceProvider(GrGpu* gpu, GrResourceCache* cache) : INHERITED(gpu, cache) {
    GR_DEFINE_STATIC_UNIQUE_KEY(gQuadIndexBufferKey);
    fQuadIndexBufferKey = gQuadIndexBufferKey;
}

const GrIndexBuffer* GrResourceProvider::createInstancedIndexBuffer(const uint16_t* pattern,
                                                                    int patternSize,
                                                                    int reps,
                                                                    int vertCount,
                                                                    const GrUniqueKey& key) {
    size_t bufferSize = patternSize * reps * sizeof(uint16_t);

    GrIndexBuffer* buffer = this->gpu()->createIndexBuffer(bufferSize, /* dynamic = */ false);
    if (!buffer) {
        return NULL;
    }
    uint16_t* data = (uint16_t*) buffer->map();
    bool useTempData = (NULL == data);
    if (useTempData) {
        data = SkNEW_ARRAY(uint16_t, reps * patternSize);
    }
    for (int i = 0; i < reps; ++i) {
        int baseIdx = i * patternSize;
        uint16_t baseVert = (uint16_t)(i * vertCount);
        for (int j = 0; j < patternSize; ++j) {
            data[baseIdx+j] = baseVert + pattern[j];
        }
    }
    if (useTempData) {
        if (!buffer->updateData(data, bufferSize)) {
            buffer->unref();
            return NULL;
        }
        SkDELETE_ARRAY(data);
    } else {
        buffer->unmap();
    }
    this->assignUniqueKeyToResource(key, buffer);
    return buffer;
}

const GrIndexBuffer* GrResourceProvider::createQuadIndexBuffer() {
    static const int kMaxQuads = 1 << 12; // max possible: (1 << 14) - 1;
    GR_STATIC_ASSERT(4 * kMaxQuads <= 65535);
    static const uint16_t kPattern[] = { 0, 1, 2, 0, 2, 3 };

    return this->createInstancedIndexBuffer(kPattern, 6, kMaxQuads, 4, fQuadIndexBufferKey);
}