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 "GrGLGpu.h"
12
13 namespace {
verb_to_gl_path_cmd(SkPath::Verb verb)14 inline 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 GR_GL_CONIC_CURVE_TO,
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(3 == SkPath::kConic_Verb);
27 GR_STATIC_ASSERT(4 == SkPath::kCubic_Verb);
28 GR_STATIC_ASSERT(5 == SkPath::kClose_Verb);
29
30 SkASSERT(verb >= 0 && (size_t)verb < SK_ARRAY_COUNT(gTable));
31 return gTable[verb];
32 }
33
34 #ifdef SK_DEBUG
num_coords(SkPath::Verb verb)35 inline int num_coords(SkPath::Verb verb) {
36 static const int gTable[] = {
37 2, // move
38 2, // line
39 4, // quad
40 5, // conic
41 6, // cubic
42 0, // close
43 };
44 GR_STATIC_ASSERT(0 == SkPath::kMove_Verb);
45 GR_STATIC_ASSERT(1 == SkPath::kLine_Verb);
46 GR_STATIC_ASSERT(2 == SkPath::kQuad_Verb);
47 GR_STATIC_ASSERT(3 == SkPath::kConic_Verb);
48 GR_STATIC_ASSERT(4 == SkPath::kCubic_Verb);
49 GR_STATIC_ASSERT(5 == SkPath::kClose_Verb);
50
51 SkASSERT(verb >= 0 && (size_t)verb < SK_ARRAY_COUNT(gTable));
52 return gTable[verb];
53 }
54 #endif
55
join_to_gl_join(SkPaint::Join join)56 inline GrGLenum join_to_gl_join(SkPaint::Join join) {
57 static GrGLenum gSkJoinsToGrGLJoins[] = {
58 GR_GL_MITER_REVERT,
59 GR_GL_ROUND,
60 GR_GL_BEVEL
61 };
62 return gSkJoinsToGrGLJoins[join];
63 GR_STATIC_ASSERT(0 == SkPaint::kMiter_Join);
64 GR_STATIC_ASSERT(1 == SkPaint::kRound_Join);
65 GR_STATIC_ASSERT(2 == SkPaint::kBevel_Join);
66 GR_STATIC_ASSERT(SK_ARRAY_COUNT(gSkJoinsToGrGLJoins) == SkPaint::kJoinCount);
67 }
68
cap_to_gl_cap(SkPaint::Cap cap)69 inline GrGLenum cap_to_gl_cap(SkPaint::Cap cap) {
70 static GrGLenum gSkCapsToGrGLCaps[] = {
71 GR_GL_FLAT,
72 GR_GL_ROUND,
73 GR_GL_SQUARE
74 };
75 return gSkCapsToGrGLCaps[cap];
76 GR_STATIC_ASSERT(0 == SkPaint::kButt_Cap);
77 GR_STATIC_ASSERT(1 == SkPaint::kRound_Cap);
78 GR_STATIC_ASSERT(2 == SkPaint::kSquare_Cap);
79 GR_STATIC_ASSERT(SK_ARRAY_COUNT(gSkCapsToGrGLCaps) == SkPaint::kCapCount);
80 }
81
points_to_coords(const SkPoint points[],size_t first_point,size_t amount,GrGLfloat coords[])82 inline void points_to_coords(const SkPoint points[], size_t first_point, size_t amount,
83 GrGLfloat coords[]) {
84 for (size_t i = 0; i < amount; ++i) {
85 coords[i * 2] = SkScalarToFloat(points[first_point + i].fX);
86 coords[i * 2 + 1] = SkScalarToFloat(points[first_point + i].fY);
87 }
88 }
89 }
90
InitPathObject(GrGLGpu * gpu,GrGLuint pathID,const SkPath & skPath,const SkStrokeRec & stroke)91 void GrGLPath::InitPathObject(GrGLGpu* gpu,
92 GrGLuint pathID,
93 const SkPath& skPath,
94 const SkStrokeRec& stroke) {
95 if (!skPath.isEmpty()) {
96 int verbCnt = skPath.countVerbs();
97 int pointCnt = skPath.countPoints();
98 int minCoordCnt = pointCnt * 2;
99
100 SkSTArray<16, GrGLubyte, true> pathCommands(verbCnt);
101 SkSTArray<16, GrGLfloat, true> pathCoords(minCoordCnt);
102
103 SkDEBUGCODE(int numCoords = 0);
104
105 if ((skPath.getSegmentMasks() & SkPath::kConic_SegmentMask) == 0) {
106 // This branch does type punning, converting SkPoint* to GrGLfloat*.
107 SK_COMPILE_ASSERT(sizeof(SkPoint) == sizeof(GrGLfloat) * 2, sk_point_not_two_floats);
108 // This branch does not convert with SkScalarToFloat.
109 #ifndef SK_SCALAR_IS_FLOAT
110 #error Need SK_SCALAR_IS_FLOAT.
111 #endif
112 pathCommands.resize_back(verbCnt);
113 pathCoords.resize_back(minCoordCnt);
114 skPath.getPoints(reinterpret_cast<SkPoint*>(&pathCoords[0]), pointCnt);
115 skPath.getVerbs(&pathCommands[0], verbCnt);
116 for (int i = 0; i < verbCnt; ++i) {
117 SkPath::Verb v = static_cast<SkPath::Verb>(pathCommands[i]);
118 pathCommands[i] = verb_to_gl_path_cmd(v);
119 SkDEBUGCODE(numCoords += num_coords(v));
120 }
121 } else {
122 SkPoint points[4];
123 SkPath::RawIter iter(skPath);
124 SkPath::Verb verb;
125 while ((verb = iter.next(points)) != SkPath::kDone_Verb) {
126 pathCommands.push_back(verb_to_gl_path_cmd(verb));
127 GrGLfloat coords[6];
128 int coordsForVerb;
129 switch (verb) {
130 case SkPath::kMove_Verb:
131 points_to_coords(points, 0, 1, coords);
132 coordsForVerb = 2;
133 break;
134 case SkPath::kLine_Verb:
135 points_to_coords(points, 1, 1, coords);
136 coordsForVerb = 2;
137 break;
138 case SkPath::kConic_Verb:
139 points_to_coords(points, 1, 2, coords);
140 coords[4] = SkScalarToFloat(iter.conicWeight());
141 coordsForVerb = 5;
142 break;
143 case SkPath::kQuad_Verb:
144 points_to_coords(points, 1, 2, coords);
145 coordsForVerb = 4;
146 break;
147 case SkPath::kCubic_Verb:
148 points_to_coords(points, 1, 3, coords);
149 coordsForVerb = 6;
150 break;
151 case SkPath::kClose_Verb:
152 continue;
153 default:
154 SkASSERT(false); // Not reached.
155 continue;
156 }
157 SkDEBUGCODE(numCoords += num_coords(verb));
158 pathCoords.push_back_n(coordsForVerb, coords);
159 }
160 }
161
162 SkASSERT(verbCnt == pathCommands.count());
163 SkASSERT(numCoords == pathCoords.count());
164
165 GR_GL_CALL(gpu->glInterface(), PathCommands(pathID, pathCommands.count(), &pathCommands[0],
166 pathCoords.count(), GR_GL_FLOAT, &pathCoords[0]));
167 } else {
168 GR_GL_CALL(gpu->glInterface(), PathCommands(pathID, 0, NULL, 0, GR_GL_FLOAT, NULL));
169 }
170
171 if (stroke.needToApply()) {
172 SkASSERT(!stroke.isHairlineStyle());
173 GR_GL_CALL(gpu->glInterface(),
174 PathParameterf(pathID, GR_GL_PATH_STROKE_WIDTH, SkScalarToFloat(stroke.getWidth())));
175 GR_GL_CALL(gpu->glInterface(),
176 PathParameterf(pathID, GR_GL_PATH_MITER_LIMIT, SkScalarToFloat(stroke.getMiter())));
177 GrGLenum join = join_to_gl_join(stroke.getJoin());
178 GR_GL_CALL(gpu->glInterface(), PathParameteri(pathID, GR_GL_PATH_JOIN_STYLE, join));
179 GrGLenum cap = cap_to_gl_cap(stroke.getCap());
180 GR_GL_CALL(gpu->glInterface(), PathParameteri(pathID, GR_GL_PATH_END_CAPS, cap));
181 }
182 }
183
GrGLPath(GrGLGpu * gpu,const SkPath & path,const SkStrokeRec & stroke)184 GrGLPath::GrGLPath(GrGLGpu* gpu, const SkPath& path, const SkStrokeRec& stroke)
185 : INHERITED(gpu, path, stroke),
186 fPathID(gpu->glPathRendering()->genPaths(1)) {
187
188 InitPathObject(gpu, fPathID, fSkPath, stroke);
189
190 if (stroke.needToApply()) {
191 // FIXME: try to account for stroking, without rasterizing the stroke.
192 fBounds.outset(stroke.getWidth(), stroke.getWidth());
193 }
194 this->registerWithCache();
195 }
196
onRelease()197 void GrGLPath::onRelease() {
198 if (0 != fPathID && !this->isWrapped()) {
199 static_cast<GrGLGpu*>(this->getGpu())->glPathRendering()->deletePaths(fPathID, 1);
200 fPathID = 0;
201 }
202
203 INHERITED::onRelease();
204 }
205
onAbandon()206 void GrGLPath::onAbandon() {
207 fPathID = 0;
208
209 INHERITED::onAbandon();
210 }
211