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 "GrGLPathRendering.h"
11#include "GrGpuGL.h"
12
13namespace {
14inline GrGLubyte verb_to_gl_path_cmd(SkPath::Verb verb) {
15    static const GrGLubyte gTable[] = {
16        GR_GL_MOVE_TO,
17        GR_GL_LINE_TO,
18        GR_GL_QUADRATIC_CURVE_TO,
19        0xFF, // conic
20        GR_GL_CUBIC_CURVE_TO,
21        GR_GL_CLOSE_PATH,
22    };
23    GR_STATIC_ASSERT(0 == SkPath::kMove_Verb);
24    GR_STATIC_ASSERT(1 == SkPath::kLine_Verb);
25    GR_STATIC_ASSERT(2 == SkPath::kQuad_Verb);
26    GR_STATIC_ASSERT(4 == SkPath::kCubic_Verb);
27    GR_STATIC_ASSERT(5 == SkPath::kClose_Verb);
28
29    SkASSERT(verb >= 0 && (size_t)verb < SK_ARRAY_COUNT(gTable));
30    return gTable[verb];
31}
32
33#ifdef SK_DEBUG
34inline int num_pts(SkPath::Verb verb) {
35    static const int gTable[] = {
36        1, // move
37        1, // line
38        2, // quad
39        2, // conic
40        3, // cubic
41        0, // close
42    };
43    GR_STATIC_ASSERT(0 == SkPath::kMove_Verb);
44    GR_STATIC_ASSERT(1 == SkPath::kLine_Verb);
45    GR_STATIC_ASSERT(2 == SkPath::kQuad_Verb);
46    GR_STATIC_ASSERT(4 == SkPath::kCubic_Verb);
47    GR_STATIC_ASSERT(5 == SkPath::kClose_Verb);
48
49    SkASSERT(verb >= 0 && (size_t)verb < SK_ARRAY_COUNT(gTable));
50    return gTable[verb];
51}
52#endif
53
54inline GrGLenum join_to_gl_join(SkPaint::Join join) {
55    static GrGLenum gSkJoinsToGrGLJoins[] = {
56        GR_GL_MITER_REVERT,
57        GR_GL_ROUND,
58        GR_GL_BEVEL
59    };
60    return gSkJoinsToGrGLJoins[join];
61    GR_STATIC_ASSERT(0 == SkPaint::kMiter_Join);
62    GR_STATIC_ASSERT(1 == SkPaint::kRound_Join);
63    GR_STATIC_ASSERT(2 == SkPaint::kBevel_Join);
64    GR_STATIC_ASSERT(SK_ARRAY_COUNT(gSkJoinsToGrGLJoins) == SkPaint::kJoinCount);
65}
66
67inline GrGLenum cap_to_gl_cap(SkPaint::Cap cap) {
68    static GrGLenum gSkCapsToGrGLCaps[] = {
69        GR_GL_FLAT,
70        GR_GL_ROUND,
71        GR_GL_SQUARE
72    };
73    return gSkCapsToGrGLCaps[cap];
74    GR_STATIC_ASSERT(0 == SkPaint::kButt_Cap);
75    GR_STATIC_ASSERT(1 == SkPaint::kRound_Cap);
76    GR_STATIC_ASSERT(2 == SkPaint::kSquare_Cap);
77    GR_STATIC_ASSERT(SK_ARRAY_COUNT(gSkCapsToGrGLCaps) == SkPaint::kCapCount);
78}
79
80}
81
82static const bool kIsWrapped = false; // The constructor creates the GL path object.
83
84void GrGLPath::InitPathObject(GrGpuGL* gpu,
85                              GrGLuint pathID,
86                              const SkPath& skPath,
87                              const SkStrokeRec& stroke) {
88    if (!skPath.isEmpty()) {
89        SkSTArray<16, GrGLubyte, true> pathCommands;
90        SkSTArray<16, SkPoint, true> pathPoints;
91
92        int verbCnt = skPath.countVerbs();
93        int pointCnt = skPath.countPoints();
94        pathCommands.resize_back(verbCnt);
95        pathPoints.resize_back(pointCnt);
96
97        // TODO: Direct access to path points since we could pass them on directly.
98        skPath.getPoints(&pathPoints[0], pointCnt);
99        skPath.getVerbs(&pathCommands[0], verbCnt);
100
101        SkDEBUGCODE(int numPts = 0);
102        for (int i = 0; i < verbCnt; ++i) {
103            SkPath::Verb v = static_cast<SkPath::Verb>(pathCommands[i]);
104            pathCommands[i] = verb_to_gl_path_cmd(v);
105            SkDEBUGCODE(numPts += num_pts(v));
106        }
107        SkASSERT(pathPoints.count() == numPts);
108
109        GR_GL_CALL(gpu->glInterface(),
110                   PathCommands(pathID, verbCnt, &pathCommands[0],
111                                2 * pointCnt, GR_GL_FLOAT, &pathPoints[0]));
112    } else {
113        GR_GL_CALL(gpu->glInterface(), PathCommands(pathID, 0, NULL, 0, GR_GL_FLOAT, NULL));
114    }
115
116    if (stroke.needToApply()) {
117        SkASSERT(!stroke.isHairlineStyle());
118        GR_GL_CALL(gpu->glInterface(),
119            PathParameterf(pathID, GR_GL_PATH_STROKE_WIDTH, SkScalarToFloat(stroke.getWidth())));
120        GR_GL_CALL(gpu->glInterface(),
121            PathParameterf(pathID, GR_GL_PATH_MITER_LIMIT, SkScalarToFloat(stroke.getMiter())));
122        GrGLenum join = join_to_gl_join(stroke.getJoin());
123        GR_GL_CALL(gpu->glInterface(),
124            PathParameteri(pathID, GR_GL_PATH_JOIN_STYLE, join));
125        GrGLenum cap = cap_to_gl_cap(stroke.getCap());
126        GR_GL_CALL(gpu->glInterface(),
127            PathParameteri(pathID, GR_GL_PATH_INITIAL_END_CAP, cap));
128        GR_GL_CALL(gpu->glInterface(),
129            PathParameteri(pathID, GR_GL_PATH_TERMINAL_END_CAP, cap));
130    }
131}
132
133GrGLPath::GrGLPath(GrGpuGL* gpu, const SkPath& path, const SkStrokeRec& stroke)
134    : INHERITED(gpu, kIsWrapped, path, stroke),
135      fPathID(gpu->glPathRendering()->genPaths(1)) {
136
137    InitPathObject(gpu, fPathID, fSkPath, stroke);
138
139    if (stroke.needToApply()) {
140        // FIXME: try to account for stroking, without rasterizing the stroke.
141        fBounds.outset(stroke.getWidth(), stroke.getWidth());
142    }
143    this->registerWithCache();
144}
145
146GrGLPath::~GrGLPath() {
147    this->release();
148}
149
150void GrGLPath::onRelease() {
151    if (0 != fPathID && !this->isWrapped()) {
152        static_cast<GrGpuGL*>(this->getGpu())->glPathRendering()->deletePaths(fPathID, 1);
153        fPathID = 0;
154    }
155
156    INHERITED::onRelease();
157}
158
159void GrGLPath::onAbandon() {
160    fPathID = 0;
161
162    INHERITED::onAbandon();
163}
164