1
2/*
3 * Copyright 2012 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9#include "GrGLPath.h"
10#include "GrGpuGL.h"
11
12#define GPUGL static_cast<GrGpuGL*>(this->getGpu())
13
14#define GL_CALL(X) GR_GL_CALL(GPUGL->glInterface(), X)
15#define GL_CALL_RET(R, X) GR_GL_CALL_RET(GPUGL->glInterface(), R, X)
16
17namespace {
18inline GrGLubyte verb_to_gl_path_cmd(SkPath::Verb verb) {
19    static const GrGLubyte gTable[] = {
20        GR_GL_MOVE_TO,
21        GR_GL_LINE_TO,
22        GR_GL_QUADRATIC_CURVE_TO,
23        0xFF, // conic
24        GR_GL_CUBIC_CURVE_TO,
25        GR_GL_CLOSE_PATH,
26    };
27    GR_STATIC_ASSERT(0 == SkPath::kMove_Verb);
28    GR_STATIC_ASSERT(1 == SkPath::kLine_Verb);
29    GR_STATIC_ASSERT(2 == SkPath::kQuad_Verb);
30    GR_STATIC_ASSERT(4 == SkPath::kCubic_Verb);
31    GR_STATIC_ASSERT(5 == SkPath::kClose_Verb);
32
33    SkASSERT(verb >= 0 && (size_t)verb < SK_ARRAY_COUNT(gTable));
34    return gTable[verb];
35}
36
37#ifdef SK_DEBUG
38inline int num_pts(SkPath::Verb verb) {
39    static const int gTable[] = {
40        1, // move
41        1, // line
42        2, // quad
43        2, // conic
44        3, // cubic
45        0, // close
46    };
47    GR_STATIC_ASSERT(0 == SkPath::kMove_Verb);
48    GR_STATIC_ASSERT(1 == SkPath::kLine_Verb);
49    GR_STATIC_ASSERT(2 == SkPath::kQuad_Verb);
50    GR_STATIC_ASSERT(4 == SkPath::kCubic_Verb);
51    GR_STATIC_ASSERT(5 == SkPath::kClose_Verb);
52
53    SkASSERT(verb >= 0 && (size_t)verb < SK_ARRAY_COUNT(gTable));
54    return gTable[verb];
55}
56#endif
57
58inline GrGLenum join_to_gl_join(SkPaint::Join join) {
59    static GrGLenum gSkJoinsToGrGLJoins[] = {
60        GR_GL_MITER_REVERT,
61        GR_GL_ROUND,
62        GR_GL_BEVEL
63    };
64    return gSkJoinsToGrGLJoins[join];
65    GR_STATIC_ASSERT(0 == SkPaint::kMiter_Join);
66    GR_STATIC_ASSERT(1 == SkPaint::kRound_Join);
67    GR_STATIC_ASSERT(2 == SkPaint::kBevel_Join);
68    GR_STATIC_ASSERT(SK_ARRAY_COUNT(gSkJoinsToGrGLJoins) == SkPaint::kJoinCount);
69}
70
71inline GrGLenum cap_to_gl_cap(SkPaint::Cap cap) {
72    static GrGLenum gSkCapsToGrGLCaps[] = {
73        GR_GL_FLAT,
74        GR_GL_ROUND,
75        GR_GL_SQUARE
76    };
77    return gSkCapsToGrGLCaps[cap];
78    GR_STATIC_ASSERT(0 == SkPaint::kButt_Cap);
79    GR_STATIC_ASSERT(1 == SkPaint::kRound_Cap);
80    GR_STATIC_ASSERT(2 == SkPaint::kSquare_Cap);
81    GR_STATIC_ASSERT(SK_ARRAY_COUNT(gSkCapsToGrGLCaps) == SkPaint::kCapCount);
82}
83
84}
85
86static const bool kIsWrapped = false; // The constructor creates the GL path object.
87
88GrGLPath::GrGLPath(GrGpuGL* gpu, const SkPath& path, const SkStrokeRec& stroke)
89    : INHERITED(gpu, kIsWrapped, path, stroke) {
90    SkASSERT(!path.isEmpty());
91
92    fPathID = gpu->createGLPathObject();
93
94    SkSTArray<16, GrGLubyte, true> pathCommands;
95    SkSTArray<16, SkPoint, true> pathPoints;
96
97    int verbCnt = fSkPath.countVerbs();
98    int pointCnt = fSkPath.countPoints();
99    pathCommands.resize_back(verbCnt);
100    pathPoints.resize_back(pointCnt);
101
102    // TODO: Direct access to path points since we could pass them on directly.
103    fSkPath.getPoints(&pathPoints[0], pointCnt);
104    fSkPath.getVerbs(&pathCommands[0], verbCnt);
105
106    SkDEBUGCODE(int numPts = 0);
107    for (int i = 0; i < verbCnt; ++i) {
108        SkPath::Verb v = static_cast<SkPath::Verb>(pathCommands[i]);
109        pathCommands[i] = verb_to_gl_path_cmd(v);
110        SkDEBUGCODE(numPts += num_pts(v));
111    }
112    SkASSERT(pathPoints.count() == numPts);
113
114    GL_CALL(PathCommands(fPathID,
115                         verbCnt, &pathCommands[0],
116                         2 * pointCnt, GR_GL_FLOAT, &pathPoints[0]));
117
118    if (stroke.needToApply()) {
119        GL_CALL(PathParameterf(fPathID, GR_GL_PATH_STROKE_WIDTH, SkScalarToFloat(stroke.getWidth())));
120        GL_CALL(PathParameterf(fPathID, GR_GL_PATH_MITER_LIMIT, SkScalarToFloat(stroke.getMiter())));
121        GrGLenum join = join_to_gl_join(stroke.getJoin());
122        GL_CALL(PathParameteri(fPathID, GR_GL_PATH_JOIN_STYLE, join));
123        GrGLenum cap = cap_to_gl_cap(stroke.getCap());
124        GL_CALL(PathParameteri(fPathID, GR_GL_PATH_INITIAL_END_CAP, cap));
125        GL_CALL(PathParameteri(fPathID, GR_GL_PATH_TERMINAL_END_CAP, cap));
126
127        // FIXME: try to account for stroking, without rasterizing the stroke.
128        fBounds.outset(SkScalarToFloat(stroke.getWidth()), SkScalarToFloat(stroke.getWidth()));
129    }
130}
131
132GrGLPath::~GrGLPath() {
133    this->release();
134}
135
136void GrGLPath::onRelease() {
137    if (0 != fPathID && !this->isWrapped()) {
138        static_cast<GrGpuGL*>(this->getGpu())->deleteGLPathObject(fPathID);
139        fPathID = 0;
140    }
141
142    INHERITED::onRelease();
143}
144
145void GrGLPath::onAbandon() {
146    fPathID = 0;
147
148    INHERITED::onAbandon();
149}
150