Add EGL context for Windows.

http://codereview.appspot.com/4517133/


git-svn-id: http://skia.googlecode.com/svn/trunk@1481 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 195 insertions, 0 deletions

diff --git a/src/utils/win/SkEGLContext_Win.cpp b/src/utils/win/SkEGLContext_Win.cpp
new file mode 100644
index 0000000000..2629ac3a5f
--- /dev/null
+++ b/src/utils/win/SkEGLContext_Win.cpp
@@ -0,0 +1,195 @@
+#define WIN32_LEAN_AND_MEAN 1
+#include <Windows.h>
+#include <GL/GL.h>
+
+#include "SkEGLContext.h"
+#include "SkTypes.h"
+
+#define SK_EGL_DECLARE_PROC(F) SkEGL ## F ## Proc SkEGL ## F = NULL;
+#define SK_EGL_GET_PROC(F) SkEGL ## F = (SkEGL ## F ## Proc) \
+        wglGetProcAddress("gl" #F);
+#define SK_EGL_GET_PROC_SUFFIX(F, S) SkEGL ## F = (SkEGL ## F ## Proc) \
+        wglGetProcAddress("gl" #F #S);
+
+#define SK_EGL_FRAMEBUFFER 0x8D40
+#define SK_EGL_RENDERBUFFER 0x8D41
+#define SK_EGL_COLOR_ATTACHMENT0 0x8CE0
+#define SK_EGL_DEPTH_STENCIL 0x84F9
+#define SK_EGL_DEPTH_STENCIL_ATTACHMENT 0x821A
+#define SK_EGL_FRAMEBUFFER_COMPLETE 0x8CD5
+
+#define SK_EGL_FUNCTION_TYPE __stdcall
+typedef void (SK_EGL_FUNCTION_TYPE *SkEGLGenFramebuffersProc) (GLsizei n, GLuint *framebuffers);
+typedef void (SK_EGL_FUNCTION_TYPE *SkEGLBindFramebufferProc) (GLenum target, GLuint framebuffer);
+typedef void (SK_EGL_FUNCTION_TYPE *SkEGLGenRenderbuffersProc) (GLsizei n, GLuint *renderbuffers);
+typedef void (SK_EGL_FUNCTION_TYPE *SkEGLBindRenderbufferProc) (GLenum target, GLuint renderbuffer);
+typedef void (SK_EGL_FUNCTION_TYPE *SkEGLRenderbufferStorageProc) (GLenum target, GLenum internalformat, GLsizei width, GLsizei height);
+typedef void (SK_EGL_FUNCTION_TYPE *SkEGLFramebufferRenderbufferProc) (GLenum target, GLenum attachment, GLenum renderbuffertarget, GLuint renderbuffer);
+typedef GLenum (SK_EGL_FUNCTION_TYPE *SkEGLCheckFramebufferStatusProc) (GLenum target);
+
+SkEGLContext::SkEGLContext() :
+        fWindow(NULL)
+        , fDeviceContext(NULL)
+        , fGlRenderContext(0) {
+}
+
+SkEGLContext::~SkEGLContext() {
+    if (this->fGlRenderContext) {
+        wglDeleteContext(this->fGlRenderContext);
+    }
+    if (this->fWindow && this->fDeviceContext) {
+        ReleaseDC(this->fWindow, this->fDeviceContext);
+    }
+    if (this->fWindow) {
+        DestroyWindow(this->fWindow);
+    }
+}
+
+bool skEGLCheckExtension(const char* ext,
+                         const char* extensionString) {
+    int extLength = strlen(ext);
+
+    while (true) {
+        int n = strcspn(extensionString, " ");
+        if (n == extLength && 0 == strncmp(ext, extensionString, n)) {
+            return true;
+        }
+        if (0 == extensionString[n]) {
+            return false;
+        }
+        extensionString += n+1;
+    }
+
+    return false;
+}
+
+bool SkEGLContext::init(const int width, const int height) {
+    HINSTANCE hInstance = (HINSTANCE)GetModuleHandle(NULL);
+
+    WNDCLASS wc;
+    wc.cbClsExtra = 0;
+    wc.cbWndExtra = 0;
+    wc.hbrBackground = NULL;
+    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
+    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
+    wc.hInstance = hInstance;
+    wc.lpfnWndProc = (WNDPROC) DefWindowProc;
+    wc.lpszClassName = TEXT("Griffin");
+    wc.lpszMenuName = NULL;
+    wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
+ 
+    if (!RegisterClass(&wc)) {
+        SkDebugf("Could not register window class.\n");
+        return false;
+    }
+
+    if (!(
+        this->fWindow = CreateWindow(
+        TEXT("Griffin"),
+        TEXT("The Invisible Man"),
+        WS_OVERLAPPEDWINDOW,
+        10, 10,                 // x, y
+        200, 200,               // width, height
+        NULL, NULL,             // parent, menu
+        hInstance, NULL)        // hInstance, param
+        ))
+    {
+        SkDebugf("Could not create window.\n");
+        return false;
+    }
+
+    if (!(this->fDeviceContext = GetDC(this->fWindow))) {
+        SkDebugf("Could not get device context.\n");
+        return false;
+    }
+    
+    PIXELFORMATDESCRIPTOR pfd;
+    ZeroMemory(&pfd, sizeof(pfd));
+    pfd.nSize = sizeof(pfd);
+    pfd.nVersion = 1;
+    pfd.dwFlags = PFD_DRAW_TO_WINDOW |
+                  PFD_SUPPORT_OPENGL |
+                  PFD_DOUBLEBUFFER;
+    pfd.iPixelType = PFD_TYPE_RGBA;
+    pfd.cColorBits = 32;
+    pfd.cDepthBits = 24;
+    pfd.cStencilBits = 8;
+    pfd.iLayerType = PFD_MAIN_PLANE;
+    
+    int pixelFormat = 0;
+    if (!(pixelFormat = ChoosePixelFormat(this->fDeviceContext, &pfd))) {
+	    SkDebugf("No matching pixel format descriptor.\n");
+        return false;
+    }
+    
+    if (!SetPixelFormat(this->fDeviceContext, pixelFormat, &pfd)) {
+	    SkDebugf("Could not set the pixel format %d.\n", pixelFormat);
+        return false;
+    }
+    
+    if (!(this->fGlRenderContext = wglCreateContext(this->fDeviceContext))) {
+	    SkDebugf("Could not create rendering context.\n");
+        return false;
+    }
+
+    if (!(wglMakeCurrent(this->fDeviceContext, this->fGlRenderContext))) {
+        SkDebugf("Could not set the context.\n");
+        return false;
+    }
+
+    //TODO: in the future we need to use this context
+    // to test for WGL_ARB_create_context
+    // and then create a new window / context.
+
+    //Setup the framebuffers
+    const char* glExts =
+        reinterpret_cast<const char *>(glGetString(GL_EXTENSIONS));
+    if (!skEGLCheckExtension(
+          "GL_EXT_framebuffer_object"
+          , glExts))
+    {
+        SkDebugf("GL_EXT_framebuffer_object not found.\n");
+        return false;
+    }
+    SK_EGL_DECLARE_PROC(GenFramebuffers)
+    SK_EGL_DECLARE_PROC(BindFramebuffer)
+    SK_EGL_DECLARE_PROC(GenRenderbuffers)
+    SK_EGL_DECLARE_PROC(BindRenderbuffer)
+    SK_EGL_DECLARE_PROC(RenderbufferStorage)
+    SK_EGL_DECLARE_PROC(FramebufferRenderbuffer)
+    SK_EGL_DECLARE_PROC(CheckFramebufferStatus)
+
+    SK_EGL_GET_PROC_SUFFIX(GenFramebuffers, EXT)
+    SK_EGL_GET_PROC_SUFFIX(BindFramebuffer, EXT)
+    SK_EGL_GET_PROC_SUFFIX(GenRenderbuffers, EXT)
+    SK_EGL_GET_PROC_SUFFIX(BindRenderbuffer, EXT)
+    SK_EGL_GET_PROC_SUFFIX(RenderbufferStorage, EXT)
+    SK_EGL_GET_PROC_SUFFIX(FramebufferRenderbuffer, EXT)
+    SK_EGL_GET_PROC_SUFFIX(CheckFramebufferStatus, EXT)
+
+    GLuint fboID;
+    GLuint cbID;
+    GLuint dsID;
+    SkEGLGenFramebuffers(1, &fboID);
+    SkEGLBindFramebuffer(SK_EGL_FRAMEBUFFER, fboID);
+    SkEGLGenRenderbuffers(1, &cbID);
+    SkEGLBindRenderbuffer(SK_EGL_RENDERBUFFER, cbID);
+    SkEGLRenderbufferStorage(SK_EGL_RENDERBUFFER, GL_RGBA, width, height);
+    SkEGLFramebufferRenderbuffer(SK_EGL_FRAMEBUFFER
+                                 , SK_EGL_COLOR_ATTACHMENT0
+                                 , SK_EGL_RENDERBUFFER, cbID);
+    SkEGLGenRenderbuffers(1, &dsID);
+    SkEGLBindRenderbuffer(SK_EGL_RENDERBUFFER, dsID);
+    SkEGLRenderbufferStorage(SK_EGL_RENDERBUFFER, SK_EGL_DEPTH_STENCIL
+                             , width, height);
+    SkEGLFramebufferRenderbuffer(SK_EGL_FRAMEBUFFER
+                                 , SK_EGL_DEPTH_STENCIL_ATTACHMENT
+                                 , SK_EGL_RENDERBUFFER
+                                 , dsID);
+    glViewport(0, 0, width, height);
+    glClearStencil(0);
+    glClear(GL_STENCIL_BUFFER_BIT);
+
+    GLenum status = SkEGLCheckFramebufferStatus(SK_EGL_FRAMEBUFFER);
+    return SK_EGL_FRAMEBUFFER_COMPLETE == status;
+}