1/*
2 * Copyright 2014 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "GrPrimitiveProcessor.h"
9
10#include "GrCoordTransform.h"
11
12/**
13 * The key for an individual coord transform is made up of a matrix type, and a bit that indicates
14 * the source of the input coords.
15 */
16enum {
17    kMatrixTypeKeyBits   = 1,
18    kPositionCoords_Flag = 1 << kMatrixTypeKeyBits,
19    kTransformKeyBits    = kMatrixTypeKeyBits + 1,
20};
21
22/**
23 * We specialize the vertex code for each of these matrix types.
24 */
25enum MatrixType {
26    kNoPersp_MatrixType  = 0,
27    kGeneral_MatrixType  = 1,
28};
29
30uint32_t
31GrPrimitiveProcessor::getTransformKey(const SkTArray<const GrCoordTransform*, true>& coords,
32                                      int numCoords) const {
33    uint32_t totalKey = 0;
34    for (int t = 0; t < numCoords; ++t) {
35        uint32_t key = 0;
36        const GrCoordTransform* coordTransform = coords[t];
37        if (coordTransform->getMatrix().hasPerspective()) {
38            key |= kGeneral_MatrixType;
39        } else {
40            key |= kNoPersp_MatrixType;
41        }
42
43        if (!this->hasExplicitLocalCoords()) {
44            key |= kPositionCoords_Flag;
45        }
46
47        key <<= kTransformKeyBits * t;
48
49        SkASSERT(0 == (totalKey & key)); // keys for each transform ought not to overlap
50        totalKey |= key;
51    }
52    return totalKey;
53}
54