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#ifndef GrGLExtensions_DEFINED
9#define GrGLExtensions_DEFINED
10
11#include "include/core/SkString.h"
12#include "include/gpu/gl/GrGLFunctions.h"
13#include "include/private/SkTArray.h"
14
15#include <utility>
16
17struct GrGLInterface;
18class SkJSONWriter;
19
20/**
21 * This helper queries the current GL context for its extensions, remembers them, and can be
22 * queried. It supports both glGetString- and glGetStringi-style extension string APIs and will
23 * use the latter if it is available. It also will query for EGL extensions if a eglQueryString
24 * implementation is provided.
25 */
26class SK_API GrGLExtensions {
27public:
28    GrGLExtensions() {}
29
30    GrGLExtensions(const GrGLExtensions&);
31
32    GrGLExtensions& operator=(const GrGLExtensions&);
33
34    void swap(GrGLExtensions* that) {
35        using std::swap;
36        swap(fStrings, that->fStrings);
37        swap(fInitialized, that->fInitialized);
38    }
39
40    /**
41     * We sometimes need to use this class without having yet created a GrGLInterface. This version
42     * of init expects that getString is always non-NULL while getIntegerv and getStringi are non-
43     * NULL if on desktop GL with version 3.0 or higher. Otherwise it will fail.
44     */
45    bool init(GrGLStandard standard,
46              GrGLFunction<GrGLGetStringFn> getString,
47              GrGLFunction<GrGLGetStringiFn> getStringi,
48              GrGLFunction<GrGLGetIntegervFn> getIntegerv,
49              GrGLFunction<GrEGLQueryStringFn> queryString = nullptr,
50              GrEGLDisplay eglDisplay = nullptr);
51
52    bool isInitialized() const { return fInitialized; }
53
54    /**
55     * Queries whether an extension is present. This will fail if init() has not been called.
56     */
57    bool has(const char[]) const;
58
59    /**
60     * Removes an extension if present. Returns true if the extension was present before the call.
61     */
62    bool remove(const char[]);
63
64    /**
65     * Adds an extension to list
66     */
67    void add(const char[]);
68
69    void reset() { fStrings.reset(); }
70
71    void dumpJSON(SkJSONWriter*) const;
72
73private:
74    bool fInitialized = false;
75    SkTArray<SkString> fStrings;
76};
77
78#endif
79