From 74cbfc9c04b26c40b3a83e823021d42dfde3f1f9 Mon Sep 17 00:00:00 2001
From: bkaradzic <branimirkaradzic@gmail.com>
Date: Sun, 17 Feb 2013 18:04:40 -0800
Subject: [PATCH] GL MSAA WIP.

---
 src/glcontext_wgl.cpp | 114 ++++++++++++++++++++++++++++++++++++++++++
 src/renderer_gl.cpp   |  10 ++--
 2 files changed, 120 insertions(+), 4 deletions(-)

diff --git a/src/glcontext_wgl.cpp b/src/glcontext_wgl.cpp
index b1c01cbe..3d3cfaed 100644
--- a/src/glcontext_wgl.cpp
+++ b/src/glcontext_wgl.cpp
@@ -16,6 +16,9 @@ namespace bgfx
 	PFNWGLMAKECURRENTPROC wglMakeCurrent;
 	PFNWGLCREATECONTEXTPROC wglCreateContext;
 	PFNWGLDELETECONTEXTPROC wglDeleteContext;
+	PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB;
+	PFNWGLCHOOSEPIXELFORMATARBPROC wglChoosePixelFormatARB;
+	PFNWGLCREATECONTEXTATTRIBSARBPROC wglCreateContextAttribsARB;
 
 #	define GL_IMPORT(_optional, _proto, _func) _proto _func
 #		include "glimports.h"
@@ -80,6 +83,117 @@ namespace bgfx
 		result = wglMakeCurrent(m_hdc, m_context);
 		BGFX_FATAL(0 != result, Fatal::UnableToInitialize, "wglMakeCurrent failed!");
 
+		wglGetExtensionsStringARB = (PFNWGLGETEXTENSIONSSTRINGARBPROC)wglGetProcAddress("wglGetExtensionsStringARB");
+		wglChoosePixelFormatARB = (PFNWGLCHOOSEPIXELFORMATARBPROC)wglGetProcAddress("wglChoosePixelFormatARB");
+		wglCreateContextAttribsARB = (PFNWGLCREATECONTEXTATTRIBSARBPROC)wglGetProcAddress("wglCreateContextAttribsARB");
+
+		if (NULL != wglGetExtensionsStringARB)
+		{
+			BX_TRACE("WGL extensions:");
+			const char* extensions = (const char*)wglGetExtensionsStringARB(m_hdc);
+			if (NULL != extensions)
+			{
+				char name[1024];
+				const char* pos = extensions;
+				const char* end = extensions + strlen(extensions);
+				while (pos < end)
+				{
+					uint32_t len;
+					const char* space = strchr(pos, ' ');
+					if (NULL != space)
+					{
+						len = uint32_min(sizeof(name), (uint32_t)(space - pos) );
+					}
+					else
+					{
+						len = uint32_min(sizeof(name), (uint32_t)strlen(pos) );
+					}
+
+					strncpy(name, pos, len);
+					name[len] = '\0';
+
+					BX_TRACE("\t%s", name);
+
+					pos += len+1;
+				}
+			}
+		}
+
+#if 0
+		// An application can only set the pixel format of a window one time.
+		// Once a window's pixel format is set, it cannot be changed.
+		// MSDN: http://msdn.microsoft.com/en-us/library/windows/desktop/dd369049%28v=vs.85%29.aspx
+		if (NULL != wglChoosePixelFormatARB
+		&&  NULL != wglCreateContextAttribsARB)
+		{
+			int32_t attrs[] =
+			{
+				WGL_SAMPLE_BUFFERS_ARB, 0,
+				WGL_SAMPLES_ARB, 0,
+				WGL_SUPPORT_OPENGL_ARB, true,
+				WGL_PIXEL_TYPE_ARB, WGL_TYPE_RGBA_ARB,
+				WGL_DRAW_TO_WINDOW_ARB, true,
+				WGL_DOUBLE_BUFFER_ARB, true,
+				WGL_RED_BITS_ARB, 8,
+				WGL_BLUE_BITS_ARB, 8,
+				WGL_GREEN_BITS_ARB, 8,
+				WGL_ALPHA_BITS_ARB, 8,
+				WGL_DEPTH_BITS_ARB, 24,
+				WGL_STENCIL_BITS_ARB, 8,
+				0
+			};
+
+			uint32_t numFormats = 0;
+			do 
+			{
+				result = wglChoosePixelFormatARB(m_hdc, attrs, NULL, 1, &pixelFormat, &numFormats);
+				if (0 == result
+				||  0 == numFormats)
+				{
+					attrs[3] >>= 1;
+					attrs[1] = attrs[3] == 0 ? 0 : 1;
+				}
+
+			} while (0 == numFormats);
+
+			DescribePixelFormat(m_hdc, pixelFormat, sizeof(PIXELFORMATDESCRIPTOR), &pfd);
+
+			BX_TRACE("Pixel format:\n"
+				"\tiPixelType %d\n"
+				"\tcColorBits %d\n"
+				"\tcAlphaBits %d\n"
+				"\tcDepthBits %d\n"
+				"\tcStencilBits %d\n"
+				, pfd.iPixelType
+				, pfd.cColorBits
+				, pfd.cAlphaBits
+				, pfd.cDepthBits
+				, pfd.cStencilBits
+				);
+
+			result = SetPixelFormat(m_hdc, pixelFormat, &pfd);
+			BGFX_FATAL(0 != result, Fatal::UnableToInitialize, "SetPixelFormat failed (last err: 0x%08x)!", GetLastError() );
+
+			wglMakeCurrent(m_hdc, NULL);
+			wglDeleteContext(m_context);
+
+			const int32_t contextAttrs[] =
+			{
+				WGL_CONTEXT_MAJOR_VERSION_ARB, 2,
+				WGL_CONTEXT_MINOR_VERSION_ARB, 1,
+#if BGFX_CONFIG_DEBUG
+				WGL_CONTEXT_FLAGS_ARB, WGL_CONTEXT_DEBUG_BIT_ARB,
+#endif // BGFX_CONFIG_DEBUG
+				0
+			};
+
+			m_context = wglCreateContextAttribsARB(m_hdc, 0, contextAttrs);
+
+			result = wglMakeCurrent(m_hdc, m_context);
+			BGFX_FATAL(0 != result, Fatal::UnableToInitialize, "wglMakeCurrent failed!");
+		}
+#endif // 0
+
 		import();
 	}
 
diff --git a/src/renderer_gl.cpp b/src/renderer_gl.cpp
index 8585ab65..218ed9c0 100644
--- a/src/renderer_gl.cpp
+++ b/src/renderer_gl.cpp
@@ -178,23 +178,25 @@ namespace bgfx
 				m_textVideoMem.clear();
 
 				m_resolution = _resolution;
-				setRenderContextSize(_resolution.m_width, _resolution.m_height);
+
+				uint32_t msaa = 1<<( (m_resolution.m_flags&BGFX_RESET_MSAA_MASK)>>BGFX_RESET_MSAA_SHIFT);
+				setRenderContextSize(_resolution.m_width, _resolution.m_height, msaa);
 				updateCapture();
 			}
 		}
 
-		void setRenderContextSize(uint32_t _width, uint32_t _height)
+		void setRenderContextSize(uint32_t _width, uint32_t _height, uint32_t _msaa)
 		{
 			if (_width != 0
 			||  _height != 0)
 			{
 				if (!m_glctx.isValid() )
 				{
-					m_glctx.create(_width, _height);
+					m_glctx.create(_width, _height/*, _msaa*/);
 				}
 				else
 				{
-					m_glctx.resize(_width, _height);
+					m_glctx.resize(_width, _height/*, _msaa*/);
 				}
 			}