michael@0: 
michael@0: /*
michael@0:  * Copyright 2011 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkRefCnt.h"
michael@0: 
michael@0: #ifndef SkWGL_DEFINED
michael@0: #define SkWGL_DEFINED
michael@0: 
michael@0: /**
michael@0:  * Working with WGL extensions can be a pain. Among the reasons is that You must
michael@0:  * have a GL context to get the proc addresses, but you want to use the procs to
michael@0:  * create a context in the first place. So you have to create a dummy GL ctx to
michael@0:  * get the proc addresses.
michael@0:  *
michael@0:  * This file helps by providing SkCreateWGLInterface(). It returns a struct of
michael@0:  * function pointers that it initializes. It also has a helper function to query
michael@0:  * for WGL extensions. It handles the fact that wglGetExtensionsString is itself
michael@0:  * an extension.
michael@0:  */
michael@0: 
michael@0: #if !defined(WIN32_LEAN_AND_MEAN)
michael@0:     #define WIN32_LEAN_AND_MEAN
michael@0:     #define SK_LOCAL_LEAN_AND_MEAN
michael@0: #endif
michael@0: #include <windows.h>
michael@0: #if defined(SK_LOCAL_LEAN_AND_MEAN)
michael@0:     #undef WIN32_LEAN_AND_MEAN
michael@0:     #undef SK_LOCAL_LEAN_AND_MEAN
michael@0: #endif
michael@0: 
michael@0: #define SK_WGL_DRAW_TO_WINDOW                       0x2001
michael@0: #define SK_WGL_ACCELERATION                         0x2003
michael@0: #define SK_WGL_SUPPORT_OPENGL                       0x2010
michael@0: #define SK_WGL_DOUBLE_BUFFER                        0x2011
michael@0: #define SK_WGL_COLOR_BITS                           0x2014
michael@0: #define SK_WGL_ALPHA_BITS                           0x201B
michael@0: #define SK_WGL_STENCIL_BITS                         0x2023
michael@0: #define SK_WGL_FULL_ACCELERATION                    0x2027
michael@0: #define SK_WGL_SAMPLE_BUFFERS                       0x2041
michael@0: #define SK_WGL_SAMPLES                              0x2042
michael@0: #define SK_WGL_CONTEXT_MAJOR_VERSION                0x2091
michael@0: #define SK_WGL_CONTEXT_MINOR_VERSION                0x2092
michael@0: #define SK_WGL_CONTEXT_LAYER_PLANE                  0x2093
michael@0: #define SK_WGL_CONTEXT_FLAGS                        0x2094
michael@0: #define SK_WGL_CONTEXT_PROFILE_MASK                 0x9126
michael@0: #define SK_WGL_CONTEXT_DEBUG_BIT                    0x0001
michael@0: #define SK_WGL_CONTEXT_FORWARD_COMPATIBLE_BIT       0x0002
michael@0: #define SK_WGL_CONTEXT_CORE_PROFILE_BIT             0x00000001
michael@0: #define SK_WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT    0x00000002
michael@0: #define SK_WGL_CONTEXT_ES2_PROFILE_BIT              0x00000004
michael@0: #define SK_ERROR_INVALID_VERSION                    0x2095
michael@0: #define SK_ERROR_INVALID_PROFILE                    0x2096
michael@0: 
michael@0: class SkWGLExtensions {
michael@0: public:
michael@0:     SkWGLExtensions();
michael@0:     /**
michael@0:      * Determines if an extensions is available for a given DC.
michael@0:      * WGL_extensions_string is considered a prerequisite for all other
michael@0:      * extensions. It is necessary to check this before calling other class
michael@0:      * functions.
michael@0:      */
michael@0:     bool hasExtension(HDC dc, const char* ext) const;
michael@0: 
michael@0:     const char* getExtensionsString(HDC hdc) const;
michael@0:     BOOL choosePixelFormat(HDC hdc, const int*, const FLOAT*, UINT, int*, UINT*) const;
michael@0:     BOOL getPixelFormatAttribiv(HDC, int, int, UINT, const int*, int*) const;
michael@0:     BOOL getPixelFormatAttribfv(HDC hdc, int, int, UINT, const int*, FLOAT*) const;
michael@0:     HGLRC createContextAttribs(HDC, HGLRC, const int *) const;
michael@0: 
michael@0:     /**
michael@0:      * WGL doesn't have precise rules for the ordering of formats returned
michael@0:      * by wglChoosePixelFormat. This function helps choose among the set of
michael@0:      * formats returned by wglChoosePixelFormat. The rules in decreasing
michael@0:      * priority are:
michael@0:      *     * Choose formats with the smallest sample count that is >=
michael@0:      *       desiredSampleCount (or the largest sample count if all formats have
michael@0:      *       fewer samples than desiredSampleCount.)
michael@0:      *     * Choose formats with the fewest color samples when coverage sampling
michael@0:      *       is available.
michael@0:      *     * If the above rules leave multiple formats, choose the one that
michael@0:      *       appears first in the formats array parameter.
michael@0:      */
michael@0:     int selectFormat(const int formats[],
michael@0:                      int formatCount,
michael@0:                      HDC dc,
michael@0:                      int desiredSampleCount);
michael@0: private:
michael@0:     typedef const char* (WINAPI *GetExtensionsStringProc)(HDC hdc);
michael@0:     typedef BOOL (WINAPI *ChoosePixelFormatProc)(HDC hdc, const int *, const FLOAT *, UINT, int *, UINT *);
michael@0:     typedef BOOL (WINAPI *GetPixelFormatAttribivProc)(HDC, int, int, UINT, const int*, int*);
michael@0:     typedef BOOL (WINAPI *GetPixelFormatAttribfvProc)(HDC hdc, int, int, UINT, const int*, FLOAT*);
michael@0:     typedef HGLRC (WINAPI *CreateContextAttribsProc)(HDC hDC, HGLRC, const int *);
michael@0: 
michael@0:     GetExtensionsStringProc fGetExtensionsString;
michael@0:     ChoosePixelFormatProc fChoosePixelFormat;
michael@0:     GetPixelFormatAttribfvProc fGetPixelFormatAttribfv;
michael@0:     GetPixelFormatAttribivProc fGetPixelFormatAttribiv;
michael@0:     CreateContextAttribsProc fCreateContextAttribs;
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Helper to create an OpenGL context for a DC using WGL. Configs with a sample count >= to
michael@0:  * msaaSampleCount are preferred but if none is available then a context with a lower sample count
michael@0:  * (including non-MSAA) will be created. If preferCoreProfile is true but a core profile cannot be
michael@0:  * created then a compatible profile context will be created.
michael@0:  */
michael@0: HGLRC SkCreateWGLContext(HDC dc, int msaaSampleCount, bool preferCoreProfile);
michael@0: 
michael@0: #endif