1 
2 /*
3  * Copyright 2016 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 #ifndef TestContext_DEFINED
10 #define TestContext_DEFINED
11 
12 #include "FenceSync.h"
13 #include "GrTypes.h"
14 #include "../private/SkTemplates.h"
15 
16 namespace sk_gpu_test {
17 
18 class GpuTimer;
19 
20 /**
21  * An offscreen 3D context. This class is intended for Skia's internal testing needs and not
22  * for general use.
23  */
24 class TestContext : public SkNoncopyable {
25 public:
26     virtual ~TestContext();
27 
28     virtual bool isValid() const = 0;
29 
fenceSyncSupport()30     bool fenceSyncSupport() const { return fFenceSync != nullptr; }
fenceSync()31     FenceSync* fenceSync() { SkASSERT(fFenceSync); return fFenceSync.get(); }
32 
gpuTimingSupport()33     bool gpuTimingSupport() const { return fGpuTimer != nullptr; }
gpuTimer()34     GpuTimer* gpuTimer() const { SkASSERT(fGpuTimer); return fGpuTimer.get(); }
35 
getMaxGpuFrameLag(int * maxFrameLag)36     bool getMaxGpuFrameLag(int *maxFrameLag) const {
37         if (!fFenceSync) {
38             return false;
39         }
40         *maxFrameLag = kMaxFrameLag;
41         return true;
42     }
43 
44     void makeCurrent() const;
45 
46     virtual GrBackend backend() = 0;
47     virtual GrBackendContext backendContext() = 0;
48 
49     /** Swaps front and back buffer (if the context has such buffers) */
50     void swapBuffers();
51 
52     /**
53      * The only purpose of this function it to provide a means of scheduling
54      * work on the GPU (since all of the subclasses create primary buffers for
55      * testing that are small and not meant to be rendered to the screen).
56      *
57      * If the platform supports fence syncs (OpenGL 3.2+ or EGL_KHR_fence_sync),
58      * this will not swap any buffers, but rather emulate triple buffer synchronization
59      * using fences.
60      *
61      * Otherwise it will call the platform SwapBuffers method. This may or may
62      * not perform some sort of synchronization, depending on whether the
63      * drawing surface provided by the platform is double buffered.
64      *
65      * Implicitly performs a submit().
66      */
67     void waitOnSyncOrSwap();
68 
69     /**
70      * This notifies the context that we are deliberately testing abandoning
71      * the context. It is useful for debugging contexts that would otherwise
72      * test that GPU resources are properly deleted. It also allows a debugging
73      * context to test that further API calls are not made by Skia GPU code.
74      */
75     virtual void testAbandon();
76 
77     /** Ensures all work is submitted to the GPU for execution. */
78     virtual void submit() = 0;
79 
80     /** Wait until all GPU work is finished. */
81     virtual void finish() = 0;
82 
83 protected:
84     std::unique_ptr<FenceSync> fFenceSync;
85     std::unique_ptr<GpuTimer>  fGpuTimer;
86 
87     TestContext();
88 
89     /** This should destroy the 3D context. */
90     virtual void teardown();
91 
92     virtual void onPlatformMakeCurrent() const = 0;
93     virtual void onPlatformSwapBuffers() const = 0;
94 
95 private:
96     enum {
97         kMaxFrameLag = 3
98     };
99 
100     PlatformFence fFrameFences[kMaxFrameLag - 1];
101     int fCurrentFenceIdx;
102 
103     typedef SkNoncopyable INHERITED;
104 };
105 }  // namespace sk_gpu_test
106 #endif
107