1 /*
2 * Copyright 2013 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 "gl/GrGLExtensions.h"
9 #include "gl/GrGLDefines.h"
10 #include "gl/GrGLUtil.h"
11
12 #include "SkTSearch.h"
13 #include "SkTSort.h"
14
15 namespace { // This cannot be static because it is used as a template parameter.
extension_compare(const SkString & a,const SkString & b)16 inline bool extension_compare(const SkString& a, const SkString& b) {
17 return strcmp(a.c_str(), b.c_str()) < 0;
18 }
19 }
20
21 // finds the index of ext in strings or a negative result if ext is not found.
find_string(const SkTArray<SkString> & strings,const char ext[])22 static int find_string(const SkTArray<SkString>& strings, const char ext[]) {
23 if (strings.empty()) {
24 return -1;
25 }
26 SkString extensionStr(ext);
27 int idx = SkTSearch<SkString, extension_compare>(&strings.front(),
28 strings.count(),
29 extensionStr,
30 sizeof(SkString));
31 return idx;
32 }
33
GrGLExtensions(const GrGLExtensions & that)34 GrGLExtensions::GrGLExtensions(const GrGLExtensions& that) : fStrings(new SkTArray<SkString>) {
35 *this = that;
36 }
37
operator =(const GrGLExtensions & that)38 GrGLExtensions& GrGLExtensions::operator=(const GrGLExtensions& that) {
39 *fStrings = *that.fStrings;
40 fInitialized = that.fInitialized;
41 return *this;
42 }
43
eat_space_sep_strings(SkTArray<SkString> * out,const char in[])44 static void eat_space_sep_strings(SkTArray<SkString>* out, const char in[]) {
45 if (!in) {
46 return;
47 }
48 while (true) {
49 // skip over multiple spaces between extensions
50 while (' ' == *in) {
51 ++in;
52 }
53 // quit once we reach the end of the string.
54 if ('\0' == *in) {
55 break;
56 }
57 // we found an extension
58 size_t length = strcspn(in, " ");
59 out->push_back().set(in, length);
60 in += length;
61 }
62 }
63
init(GrGLStandard standard,GrGLFunction<GrGLGetStringProc> getString,GrGLFunction<GrGLGetStringiProc> getStringi,GrGLFunction<GrGLGetIntegervProc> getIntegerv,GrGLFunction<GrEGLQueryStringProc> queryString,GrEGLDisplay eglDisplay)64 bool GrGLExtensions::init(GrGLStandard standard,
65 GrGLFunction<GrGLGetStringProc> getString,
66 GrGLFunction<GrGLGetStringiProc> getStringi,
67 GrGLFunction<GrGLGetIntegervProc> getIntegerv,
68 GrGLFunction<GrEGLQueryStringProc> queryString,
69 GrEGLDisplay eglDisplay) {
70 fInitialized = false;
71 fStrings->reset();
72
73 if (!getString) {
74 return false;
75 }
76
77 // glGetStringi and indexed extensions were added in version 3.0 of desktop GL and ES.
78 const GrGLubyte* verString = getString(GR_GL_VERSION);
79 GrGLVersion version = GrGLGetVersionFromString((const char*) verString);
80 if (GR_GL_INVALID_VER == version) {
81 return false;
82 }
83
84 bool indexed = version >= GR_GL_VER(3, 0);
85
86 if (indexed) {
87 if (!getStringi || !getIntegerv) {
88 return false;
89 }
90 GrGLint extensionCnt = 0;
91 getIntegerv(GR_GL_NUM_EXTENSIONS, &extensionCnt);
92 fStrings->push_back_n(extensionCnt);
93 for (int i = 0; i < extensionCnt; ++i) {
94 const char* ext = (const char*) getStringi(GR_GL_EXTENSIONS, i);
95 (*fStrings)[i] = ext;
96 }
97 } else {
98 const char* extensions = (const char*) getString(GR_GL_EXTENSIONS);
99 if (!extensions) {
100 return false;
101 }
102 eat_space_sep_strings(fStrings, extensions);
103 }
104 if (queryString) {
105 const char* extensions = queryString(eglDisplay, GR_EGL_EXTENSIONS);
106
107 eat_space_sep_strings(fStrings, extensions);
108 }
109 if (!fStrings->empty()) {
110 SkTLessFunctionToFunctorAdaptor<SkString, extension_compare> cmp;
111 SkTQSort(&fStrings->front(), &fStrings->back(), cmp);
112 }
113 fInitialized = true;
114 return true;
115 }
116
has(const char ext[]) const117 bool GrGLExtensions::has(const char ext[]) const {
118 SkASSERT(fInitialized);
119 return find_string(*fStrings, ext) >= 0;
120 }
121
remove(const char ext[])122 bool GrGLExtensions::remove(const char ext[]) {
123 SkASSERT(fInitialized);
124 int idx = find_string(*fStrings, ext);
125 if (idx >= 0) {
126 // This is not terribly effecient but we really only expect this function to be called at
127 // most a handful of times when our test programs start.
128 SkAutoTDelete< SkTArray<SkString> > oldStrings(fStrings.release());
129 fStrings.reset(new SkTArray<SkString>(oldStrings->count() - 1));
130 fStrings->push_back_n(idx, &oldStrings->front());
131 fStrings->push_back_n(oldStrings->count() - idx - 1, &(*oldStrings)[idx] + 1);
132 return true;
133 } else {
134 return false;
135 }
136 }
137
add(const char ext[])138 void GrGLExtensions::add(const char ext[]) {
139 int idx = find_string(*fStrings, ext);
140 if (idx < 0) {
141 // This is not the most effecient approach since we end up doing a full sort of the
142 // extensions after the add
143 fStrings->push_back().set(ext);
144 SkTLessFunctionToFunctorAdaptor<SkString, extension_compare> cmp;
145 SkTQSort(&fStrings->front(), &fStrings->back(), cmp);
146 }
147 }
148
print(const char * sep) const149 void GrGLExtensions::print(const char* sep) const {
150 if (nullptr == sep) {
151 sep = " ";
152 }
153 int cnt = fStrings->count();
154 for (int i = 0; i < cnt; ++i) {
155 SkDebugf("%s%s", (*fStrings)[i].c_str(), (i < cnt - 1) ? sep : "");
156 }
157 }
158