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, a precision, and a bit
14 * that indicates the source of the input coords.
15 */
16 enum {
17 kMatrixTypeKeyBits = 1,
18 kMatrixTypeKeyMask = (1 << kMatrixTypeKeyBits) - 1,
19
20 kPrecisionBits = 2,
21 kPrecisionShift = kMatrixTypeKeyBits,
22
23 kPositionCoords_Flag = (1 << (kPrecisionShift + kPrecisionBits)),
24
25 kTransformKeyBits = kMatrixTypeKeyBits + kPrecisionBits + 2,
26 };
27
28 GR_STATIC_ASSERT(kHigh_GrSLPrecision < (1 << kPrecisionBits));
29
30 /**
31 * We specialize the vertex code for each of these matrix types.
32 */
33 enum MatrixType {
34 kNoPersp_MatrixType = 0,
35 kGeneral_MatrixType = 1,
36 };
37
38 uint32_t
getTransformKey(const SkTArray<const GrCoordTransform *,true> & coords,int numCoords) const39 GrPrimitiveProcessor::getTransformKey(const SkTArray<const GrCoordTransform*, true>& coords,
40 int numCoords) const {
41 uint32_t totalKey = 0;
42 for (int t = 0; t < numCoords; ++t) {
43 uint32_t key = 0;
44 const GrCoordTransform* coordTransform = coords[t];
45 if (coordTransform->getMatrix().hasPerspective()) {
46 key |= kGeneral_MatrixType;
47 } else {
48 key |= kNoPersp_MatrixType;
49 }
50
51 if (!this->hasExplicitLocalCoords()) {
52 key |= kPositionCoords_Flag;
53 }
54
55 GR_STATIC_ASSERT(kGrSLPrecisionCount <= (1 << kPrecisionBits));
56 key |= (coordTransform->precision() << kPrecisionShift);
57
58 key <<= kTransformKeyBits * t;
59
60 SkASSERT(0 == (totalKey & key)); // keys for each transform ought not to overlap
61 totalKey |= key;
62 }
63 return totalKey;
64 }
65