Move instanced index buffer creation to flush time

src/gpu/GrResourceProvider.cpp

+/*
+ * 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);
+}
+