Use glGetStringi to get extensions when available.
Review URL: https://codereview.chromium.org/12328111
git-svn-id: http://skia.googlecode.com/svn/trunk@7872 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGLExtensions.cpp b/src/gpu/gl/GrGLExtensions.cpp
new file mode 100644
index 0000000..b5df2cc
--- /dev/null
+++ b/src/gpu/gl/GrGLExtensions.cpp
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gl/GrGLExtensions.h"
+#include "gl/GrGLDefines.h"
+#include "gl/GrGLUtil.h"
+
+bool GrGLExtensions::init(GrGLBinding binding,
+ GrGLGetStringProc getString,
+ GrGLGetStringiProc getStringi,
+ GrGLGetIntegervProc getIntegerv) {
+ fStrings.reset();
+ if (NULL == getString) {
+ return false;
+ }
+ bool indexed = false;
+ if (kDesktop_GrGLBinding == binding) {
+ const GrGLubyte* verString = getString(GR_GL_VERSION);
+ if (NULL == verString) {
+ return false;
+ }
+ GrGLVersion version = GrGLGetVersionFromString((const char*) verString);
+ indexed = version >= GR_GL_VER(3, 0);
+ }
+ if (indexed) {
+ if (NULL == getStringi || NULL == getIntegerv) {
+ return false;
+ }
+ GrGLint extensionCnt = 0;
+ getIntegerv(GR_GL_NUM_EXTENSIONS, &extensionCnt);
+ fStrings.push_back_n(extensionCnt);
+ for (int i = 0; i < extensionCnt; ++i) {
+ const char* ext = (const char*) getStringi(GR_GL_EXTENSIONS, i);
+ fStrings[i] = ext;
+ }
+ } else {
+ const char* extensions = (const char*) getString(GR_GL_EXTENSIONS);
+ if (NULL == extensions) {
+ return false;
+ }
+ // First count the extensions so that we don't cause the array to malloc multiple times.
+ int extensionCnt = 1;
+ const char* e = (const char*) extensions;
+ while (NULL != (e = strchr(e+1, ' '))) {
+ e += 1;
+ ++extensionCnt;
+ }
+ fStrings.push_back_n(extensionCnt);
+
+ int i = 0;
+ while (true) {
+ size_t length = strcspn(extensions, " ");
+ GrAssert(i < extensionCnt);
+ fStrings[i].set(extensions, length);
+ ++i;
+ if ('\0' == extensions[length]) {
+ break;
+ }
+ extensions += length + 1;
+ }
+ GrAssert(i == extensionCnt);
+ }
+ return true;
+}
+
+bool GrGLExtensions::has(const char* ext) const {
+ // TODO: Sort the extensions and binary search.
+ int count = fStrings.count();
+ for (int i = 0; i < count; ++i) {
+ if (fStrings[i].equals(ext)) {
+ return true;
+ }
+ }
+ return false;
+}