skia: add ability to load command_buffer_gles2

src/gpu/gl/command_buffer/SkCommandBufferGLContext.cpp

Index: src/gpu/gl/command_buffer/SkCommandBufferGLContext.cpp
diff --git a/src/gpu/gl/command_buffer/SkCommandBufferGLContext.cpp b/src/gpu/gl/command_buffer/SkCommandBufferGLContext.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..a5a765b9167856bcfab579072c483cbe02a73c98
--- /dev/null
+++ b/src/gpu/gl/command_buffer/SkCommandBufferGLContext.cpp
@@ -0,0 +1,271 @@
+
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include <EGL/egl.h>
+
+#include "SkOnce.h"
+#include "gl/GrGLInterface.h"
+#include "gl/GrGLAssembleInterface.h"
+#include "gl/command_buffer/SkCommandBufferGLContext.h"
+
+typedef EGLDisplay (*GetDisplayProc)(EGLNativeDisplayType display_id);
+typedef EGLBoolean (*InitializeProc)(EGLDisplay dpy, EGLint *major, EGLint *minor);
+typedef EGLBoolean (*TerminateProc)(EGLDisplay dpy);
+typedef EGLBoolean (*ChooseConfigProc)(EGLDisplay dpy, const EGLint* attrib_list, EGLConfig* configs, EGLint config_size, EGLint* num_config);
+typedef EGLBoolean (*GetConfigAttrib)(EGLDisplay dpy, EGLConfig config, EGLint attribute, EGLint* value);
+typedef EGLSurface (*CreateWindowSurfaceProc)(EGLDisplay dpy, EGLConfig config, EGLNativeWindowType win, const EGLint* attrib_list);
+typedef EGLSurface (*CreatePbufferSurfaceProc)(EGLDisplay dpy, EGLConfig config, const EGLint* attrib_list);
+typedef EGLBoolean (*DestroySurfaceProc)(EGLDisplay dpy, EGLSurface surface);
+typedef EGLContext (*CreateContextProc)(EGLDisplay dpy, EGLConfig config, EGLContext share_context, const EGLint* attrib_list);
+typedef EGLBoolean (*DestroyContextProc)(EGLDisplay dpy, EGLContext ctx);
+typedef EGLBoolean (*MakeCurrentProc)(EGLDisplay dpy, EGLSurface draw, EGLSurface read, EGLContext ctx);
+typedef EGLBoolean (*SwapBuffersProc)(EGLDisplay dpy, EGLSurface surface);
+typedef __eglMustCastToProperFunctionPointerType (*GetProcAddressProc)(const char* procname);
+
+static GetDisplayProc gfGetDisplay = nullptr;
+static InitializeProc gfInitialize = nullptr;
+static TerminateProc gfTerminate = nullptr;
+static ChooseConfigProc gfChooseConfig = nullptr;
+static GetConfigAttrib gfGetConfigAttrib = nullptr;
+static CreateWindowSurfaceProc gfCreateWindowSurface = nullptr;
+static CreatePbufferSurfaceProc gfCreatePbufferSurface = nullptr;
+static DestroySurfaceProc gfDestroySurface = nullptr;
+static CreateContextProc gfCreateContext = nullptr;
+static DestroyContextProc gfDestroyContext = nullptr;
+static MakeCurrentProc gfMakeCurrent = nullptr;
+static SwapBuffersProc gfSwapBuffers = nullptr;
+static GetProcAddressProc gfGetProcAddress = nullptr;
+
+static HMODULE ghLibrary = nullptr;
+static bool gfFunctionsLoadedSuccessfully = false;
+
+static void load_command_buffer_functions() {
+    if (!ghLibrary) {
+        ghLibrary = LoadLibrary("command_buffer_gles2.dll");
+
+        if (ghLibrary) {
+            gfGetDisplay = (GetDisplayProc)::GetProcAddress(ghLibrary, "CommandBuffer_GetDisplay");
+            gfInitialize = (InitializeProc)::GetProcAddress(ghLibrary, "CommandBuffer_Initialize");
+            gfTerminate = (TerminateProc)::GetProcAddress(ghLibrary, "CommandBuffer_Terminate");
+            gfChooseConfig = (ChooseConfigProc)::GetProcAddress(ghLibrary, "CommandBuffer_ChooseConfig");
+            gfGetConfigAttrib = (GetConfigAttrib)::GetProcAddress(ghLibrary, "CommandBuffer_GetConfigAttrib");
+            gfCreateWindowSurface = (CreateWindowSurfaceProc)::GetProcAddress(ghLibrary, "CommandBuffer_CreateWindowSurface");
+            gfCreatePbufferSurface = (CreatePbufferSurfaceProc)::GetProcAddress(ghLibrary, "CommandBuffer_CreatePbufferSurface");
+            gfDestroySurface = (DestroySurfaceProc)::GetProcAddress(ghLibrary, "CommandBuffer_DestroySurface");
+            gfCreateContext = (CreateContextProc)::GetProcAddress(ghLibrary, "CommandBuffer_CreateContext");
+            gfDestroyContext = (DestroyContextProc)::GetProcAddress(ghLibrary, "CommandBuffer_DestroyContext");
+            gfMakeCurrent = (MakeCurrentProc)::GetProcAddress(ghLibrary, "CommandBuffer_MakeCurrent");
+            gfSwapBuffers = (SwapBuffersProc)::GetProcAddress(ghLibrary, "CommandBuffer_SwapBuffers");
+            gfGetProcAddress = (GetProcAddressProc)::GetProcAddress(ghLibrary, "CommandBuffer_GetProcAddress");
+
+            gfFunctionsLoadedSuccessfully = gfGetDisplay && gfInitialize && gfTerminate &&
+                                            gfChooseConfig && gfCreateWindowSurface &&
+                                            gfCreatePbufferSurface && gfDestroySurface &&
+                                            gfCreateContext && gfDestroyContext && gfMakeCurrent &&
+                                            gfSwapBuffers && gfGetProcAddress;
+
+        }                        
+    }                            
+}
+
+static GrGLFuncPtr command_buffer_get_gl_proc(void* ctx, const char name[]) {
+    GrGLFuncPtr proc = (GrGLFuncPtr) GetProcAddress((HMODULE)ctx, name);
+    if (proc) {
+        return proc;
+    }
+    if (!gfFunctionsLoadedSuccessfully) {
+        return nullptr;
+    }
+    return gfGetProcAddress(name);
+}
+
+SK_DECLARE_STATIC_ONCE(loadCommandBufferOnce);
+void LoadCommandBufferOnce() {
+    SkOnce(&loadCommandBufferOnce, load_command_buffer_functions);
+}
+
+const GrGLInterface* GrGLCreateCommandBufferInterface() {
+    LoadCommandBufferOnce();
+    if (!gfFunctionsLoadedSuccessfully) {
+        return nullptr;
+    }
+    return GrGLAssembleGLESInterface(ghLibrary, command_buffer_get_gl_proc);
+}
+
+SkCommandBufferGLContext::SkCommandBufferGLContext()
+    : fContext(EGL_NO_CONTEXT)
+    , fDisplay(EGL_NO_DISPLAY)
+    , fSurface(EGL_NO_SURFACE) {
+
+    static const EGLint configAttribs[] = {
+        EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
+        EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+        EGL_RED_SIZE, 8,
+        EGL_GREEN_SIZE, 8,
+        EGL_BLUE_SIZE, 8,
+        EGL_ALPHA_SIZE, 8,
+        EGL_NONE
+    };
+
+    static const EGLint surfaceAttribs[] = {
+        EGL_WIDTH, 1,
+        EGL_HEIGHT, 1,
+        EGL_NONE
+    };
+
+    initializeGLContext(nullptr, configAttribs, surfaceAttribs);
+}
+
+SkCommandBufferGLContext::SkCommandBufferGLContext(void* nativeWindow, int msaaSampleCount) {
+    static const EGLint surfaceAttribs[] = { EGL_NONE };
+
+    EGLint configAttribs[] = {
+        EGL_RED_SIZE,       8,
+        EGL_GREEN_SIZE,     8,
+        EGL_BLUE_SIZE,      8,
+        EGL_ALPHA_SIZE,     8,
+        EGL_DEPTH_SIZE,     8,
+        EGL_STENCIL_SIZE,   8,
+        EGL_SAMPLE_BUFFERS, 1,
+        EGL_SAMPLES,        msaaSampleCount,
+        EGL_NONE
+    };
+    if (msaaSampleCount == 0) {
+        configAttribs[12] = EGL_NONE;
+    }
+
+    initializeGLContext(nativeWindow, configAttribs, surfaceAttribs);
+}
+
+void SkCommandBufferGLContext::initializeGLContext(void* nativeWindow, const int* configAttribs,
+                                                   const int* surfaceAttribs) {
+    LoadCommandBufferOnce();
+    if (!gfFunctionsLoadedSuccessfully) {
+        return;
+    }
+
+    fDisplay = gfGetDisplay(static_cast<EGLNativeDisplayType>(EGL_DEFAULT_DISPLAY));
+    if (EGL_NO_DISPLAY == fDisplay) {
+        SkDebugf("Could not create EGL display!");
+        return;
+    }
+
+    EGLint majorVersion;
+    EGLint minorVersion;
+    gfInitialize(fDisplay, &majorVersion, &minorVersion);
+
+    EGLConfig surfaceConfig = static_cast<EGLConfig>(fConfig);
+    EGLint numConfigs;
+    gfChooseConfig(fDisplay, configAttribs, &surfaceConfig, 1, &numConfigs);
+
+    if (nativeWindow) {
+        fSurface = gfCreateWindowSurface(fDisplay, surfaceConfig, 
+                                         (EGLNativeWindowType)nativeWindow, surfaceAttribs);
+    } else {
+        fSurface = gfCreatePbufferSurface(fDisplay, surfaceConfig, surfaceAttribs);
+    }
+
+    static const EGLint contextAttribs[] = {
+        EGL_CONTEXT_CLIENT_VERSION, 2,
+        EGL_NONE
+    };
+    fContext = gfCreateContext(fDisplay, surfaceConfig, nullptr, contextAttribs);
+
+    gfMakeCurrent(fDisplay, fSurface, fSurface, fContext);
+
+    SkAutoTUnref<const GrGLInterface> gl(GrGLCreateCommandBufferInterface());
+    if (nullptr == gl.get()) {
+        SkDebugf("Could not create CommandBuffer GL interface!\n");
+        this->destroyGLContext();
+        return;
+    }
+    if (!gl->validate()) {
+        SkDebugf("Could not validate CommandBuffer GL interface!\n");
+        this->destroyGLContext();
+        return;
+    }
+
+    this->init(gl.detach());
+}
+
+SkCommandBufferGLContext::~SkCommandBufferGLContext() {
+    this->teardown();
+    this->destroyGLContext();
+}
+
+void SkCommandBufferGLContext::destroyGLContext() {
+    if (!gfFunctionsLoadedSuccessfully) {
+        return;
+    }
+    if (fDisplay) {
+        gfMakeCurrent(fDisplay, 0, 0, 0);
+
+        if (fContext) {
+            gfDestroyContext(fDisplay, fContext);
+            fContext = EGL_NO_CONTEXT;
+        }
+
+        if (fSurface) {
+            gfDestroySurface(fDisplay, fSurface);
+            fSurface = EGL_NO_SURFACE;
+        }
+
+        gfTerminate(fDisplay);
+        fDisplay = EGL_NO_DISPLAY;
+    }
+}
+
+void SkCommandBufferGLContext::onPlatformMakeCurrent() const {
+    if (!gfFunctionsLoadedSuccessfully) {
+        return;
+    }
+    if (!gfMakeCurrent(fDisplay, fSurface, fSurface, fContext)) {
+        SkDebugf("Could not set the context.\n");
+    }
+}
+
+void SkCommandBufferGLContext::onPlatformSwapBuffers() const {
+    if (!gfFunctionsLoadedSuccessfully) {
+        return;
+    }
+    if (!gfSwapBuffers(fDisplay, fSurface)) {
+        SkDebugf("Could not complete gfSwapBuffers.\n");
+    }
+}
+
+GrGLFuncPtr SkCommandBufferGLContext::onPlatformGetProcAddress(const char* name) const {
+    if (!gfFunctionsLoadedSuccessfully) {
+        return nullptr;
+    }
+    return gfGetProcAddress(name);
+}
+
+void SkCommandBufferGLContext::presentCommandBuffer() {
+    if (this->gl()) {
+        this->gl()->fFunctions.fFlush();
+    }
+
+    this->onPlatformSwapBuffers();
+}
+
+bool SkCommandBufferGLContext::makeCurrent() {
+    return gfMakeCurrent(fDisplay, fSurface, fSurface, fContext) != EGL_FALSE;
+}
+
+int SkCommandBufferGLContext::getStencilBits() {
+    EGLint result = 0;
+    EGLConfig surfaceConfig = static_cast<EGLConfig>(fConfig);
+    gfGetConfigAttrib(fDisplay, surfaceConfig, EGL_STENCIL_SIZE, &result);
+    return result;
+}
+
+int SkCommandBufferGLContext::getSampleCount() {
+    EGLint result = 0;
+    EGLConfig surfaceConfig = static_cast<EGLConfig>(fConfig);
+    gfGetConfigAttrib(fDisplay, surfaceConfig, EGL_SAMPLES, &result);
+    return result;
+}