iOS SwapChain support

src/glcontext_eagl.h

@@ -15,7 +15,11 @@ namespace bgfx { namespace gl
 	struct GlContext
 	{
 		GlContext()
-			: m_context(0)
+			: m_current(0)
+			, m_context(0)
+			, m_fbo(0)
+			, m_colorRbo(0)
+			, m_depthStencilRbo(0)
 		{
 		}
 
@@ -41,7 +45,7 @@ namespace bgfx { namespace gl
 			return 0 != m_context;
 		}
 
-		void* m_view;
+		SwapChainGL* m_current;
 		void* m_context;
 
 		GLuint m_fbo;

src/glcontext_eagl.mm

@@ -17,6 +17,142 @@ namespace bgfx { namespace gl
 
 	static void* s_opengles = NULL;
 
+	struct SwapChainGL
+	{
+		SwapChainGL(EAGLContext *_context, CAEAGLLayer *_layer)
+		: m_context(_context)
+		, m_fbo(0)
+		, m_colorRbo(0)
+		, m_depthStencilRbo(0)
+		{
+			_layer.contentsScale = [UIScreen mainScreen].scale;
+
+			_layer.opaque = true;
+
+			_layer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys
+                                        : [NSNumber numberWithBool:false]
+                                        , kEAGLDrawablePropertyRetainedBacking
+                                        , kEAGLColorFormatRGBA8
+                                        , kEAGLDrawablePropertyColorFormat
+                                        , nil
+                                        ];
+
+
+            [EAGLContext setCurrentContext:_context];
+
+            GL_CHECK(glGenFramebuffers(1, &m_fbo) );
+            GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, m_fbo) );
+
+            GL_CHECK(glGenRenderbuffers(1, &m_colorRbo) );
+            GL_CHECK(glBindRenderbuffer(GL_RENDERBUFFER, m_colorRbo) );
+
+            [_context renderbufferStorage:GL_RENDERBUFFER fromDrawable:_layer];
+            GL_CHECK(glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, m_colorRbo) );
+
+            GLint width;
+            GLint height;
+            GL_CHECK(glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &width) );
+            GL_CHECK(glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &height) );
+            BX_TRACE("Screen size: %d x %d", width, height);
+
+            m_width = width;
+            m_height = height;
+            m_layer = _layer;
+
+            createFrameBuffers(m_width, m_height);
+		}
+
+		~SwapChainGL()
+		{
+            destroyFrameBuffers();
+		}
+
+        void destroyFrameBuffers()
+        {
+            GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, 0) );
+            GL_CHECK(glBindRenderbuffer(GL_RENDERBUFFER, 0) );
+            GL_CHECK(glBindRenderbuffer(GL_RENDERBUFFER, 0) );
+            if (0 != m_fbo)
+            {
+                GL_CHECK(glDeleteFramebuffers(1, &m_fbo) );
+                m_fbo = 0;
+            }
+
+            if (0 != m_colorRbo)
+            {
+                GL_CHECK(glDeleteRenderbuffers(1, &m_colorRbo) );
+                m_colorRbo = 0;
+            }
+
+            if (0 != m_depthStencilRbo)
+            {
+                GL_CHECK(glDeleteRenderbuffers(1, &m_depthStencilRbo) );
+                m_depthStencilRbo = 0;
+            }
+        }
+
+        void createFrameBuffers(GLint _width, GLint _height)
+        {
+            GL_CHECK(glGenRenderbuffers(1, &m_depthStencilRbo) );
+            GL_CHECK(glBindRenderbuffer(GL_RENDERBUFFER, m_depthStencilRbo) );
+            GL_CHECK(glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8_OES, _width, _height) ); // from OES_packed_depth_stencil
+            GL_CHECK(glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, m_depthStencilRbo) );
+            GL_CHECK(glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, m_depthStencilRbo) );
+
+            BX_CHECK(GL_FRAMEBUFFER_COMPLETE ==  glCheckFramebufferStatus(GL_FRAMEBUFFER)
+                     , "glCheckFramebufferStatus failed 0x%08x"
+                     , glCheckFramebufferStatus(GL_FRAMEBUFFER)
+                     );
+
+            makeCurrent();
+            GL_CHECK(glClearColor(0.0f, 0.0f, 0.0f, 0.0f) );
+            GL_CHECK(glClear(GL_COLOR_BUFFER_BIT) );
+            swapBuffers();
+            GL_CHECK(glClear(GL_COLOR_BUFFER_BIT) );
+            swapBuffers();
+        }
+
+		void makeCurrent()
+		{
+            [EAGLContext setCurrentContext:m_context];
+            GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, m_fbo) );
+
+            GLint newWidth = m_layer.bounds.size.width*[UIScreen mainScreen].scale;
+            GLint newHeight = m_layer.bounds.size.height*[UIScreen mainScreen].scale;
+            resize(newWidth, newHeight);
+		}
+
+        void resize(GLint _width, GLint _height)
+        {
+            if(m_width == _width && m_height == _height)
+            {
+                return;
+            }
+
+            destroyFrameBuffers();
+
+            m_width = _width;
+            m_height = _height;
+
+            createFrameBuffers(m_width, m_height);
+        }
+
+		void swapBuffers()
+		{
+            GL_CHECK(glBindRenderbuffer(GL_RENDERBUFFER, m_colorRbo) );
+            [m_context presentRenderbuffer:GL_RENDERBUFFER];
+		}
+
+		EAGLContext* m_context;
+
+        CAEAGLLayer *m_layer;
+		GLuint m_fbo;
+		GLuint m_colorRbo;
+		GLuint m_depthStencilRbo;
+        GLint m_width;
+        GLint m_height;
+	};
+
 	void GlContext::create(uint32_t _width, uint32_t _height)
 	{
 		s_opengles = bx::dlopen("/System/Library/Frameworks/OpenGLES.framework/OpenGLES");
@@ -65,6 +201,13 @@ namespace bgfx { namespace gl
 			, glCheckFramebufferStatus(GL_FRAMEBUFFER)
 			);
 
+        makeCurrent();
+        GL_CHECK(glClearColor(0.0f, 0.0f, 0.0f, 0.0f) );
+        GL_CHECK(glClear(GL_COLOR_BUFFER_BIT) );
+        swap(NULL);
+        GL_CHECK(glClear(GL_COLOR_BUFFER_BIT) );
+        swap(NULL);
+
 		import();
 
 		g_internalData.context = m_context;
@@ -148,30 +291,51 @@ namespace bgfx { namespace gl
 
 	uint64_t GlContext::getCaps() const
 	{
-		return 0;
+		return BGFX_CAPS_SWAP_CHAIN;
 	}
 
-	SwapChainGL* GlContext::createSwapChain(void* /*_nwh*/)
+	SwapChainGL* GlContext::createSwapChain(void* _nwh)
 	{
-		BX_CHECK(false, "Shouldn't be called!");
-		return NULL;
+		return BX_NEW(g_allocator, SwapChainGL)(/*m_display, m_config,*/ (EAGLContext*)m_context, (CAEAGLLayer*)_nwh);
 	}
 
-	void GlContext::destroySwapChain(SwapChainGL*  /*_swapChain*/)
+	void GlContext::destroySwapChain(SwapChainGL* _swapChain)
 	{
-		BX_CHECK(false, "Shouldn't be called!");
+		BX_DELETE(g_allocator, _swapChain);
 	}
 
 	void GlContext::swap(SwapChainGL* _swapChain)
 	{
-		BX_CHECK(NULL == _swapChain, "Shouldn't be called!"); BX_UNUSED(_swapChain);
-		GL_CHECK(glBindRenderbuffer(GL_RENDERBUFFER, m_colorRbo) );
-		EAGLContext* context = (EAGLContext*)m_context;
-		[context presentRenderbuffer:GL_RENDERBUFFER];
+        makeCurrent(_swapChain);
+
+        if (NULL == _swapChain)
+        {
+            GL_CHECK(glBindRenderbuffer(GL_RENDERBUFFER, m_colorRbo) );
+            EAGLContext* context = (EAGLContext*)m_context;
+            [context presentRenderbuffer:GL_RENDERBUFFER];
+        }
+        else
+        {
+            _swapChain->swapBuffers();
+        }
 	}
 
-	void GlContext::makeCurrent(SwapChainGL* /*_swapChain*/)
+	void GlContext::makeCurrent(SwapChainGL* _swapChain)
 	{
+		if (m_current != _swapChain)
+		{
+			m_current = _swapChain;
+
+			if (NULL == _swapChain)
+			{
+                [EAGLContext setCurrentContext:(EAGLContext*)m_context];
+                GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, m_fbo) );
+			}
+			else
+			{
+				_swapChain->makeCurrent();
+			}
+		}
 	}
 
 	void GlContext::import()

src/renderer_gl.cpp

@@ -2562,16 +2562,7 @@ namespace bgfx { namespace gl
 			{
 				FrameBufferGL& frameBuffer = m_frameBuffers[_fbh.idx];
 				_height = frameBuffer.m_height;
-				if (UINT16_MAX != frameBuffer.m_denseIdx)
-				{
-					m_glctx.makeCurrent(frameBuffer.m_swapChain);
-					GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, 0) );
-				}
-				else
-				{
-					m_glctx.makeCurrent(NULL);
-					GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, frameBuffer.m_fbo[0]) );
-				}
+                m_glctx.makeCurrent(frameBuffer.m_swapChain);
 			}
 
 			m_fbh       = _fbh;