Fix issue #294 (really this time).

Add stencil attachment to framebuffer creation. Needed to remove depth
attachment to make it work, but that should not change anything, since depth
test is not enabled anyway. May need testing nonetheless.

src/modules/graphics/opengl/Canvas.cpp

@@ -14,39 +14,44 @@ namespace opengl
 	// strategy for fbo creation, interchangable at runtime:
 	// none, opengl >= 3.0, extensions
 	struct FramebufferStrategy {
-		/// create a new framebuffer, depthbuffer and texture
+		/// create a new framebuffer, stencilbuffer and texture
 		/**
-		 * @param[out] framebuffer Framebuffer name
-		 * @param[out] depthbuffer Depthbuffer name
-		 * @param[out] img         Texture name
-		 * @param[in]  width       Width of framebuffer
-		 * @param[in]  height      Height of framebuffer
+		 * @param[out] framebuffer   Framebuffer name
+		 * @param[out] stencilbuffer Stencilbuffer name
+		 * @param[out] img           Texture name
+		 * @param[in]  width         Width of framebuffer
+		 * @param[in]  height        Height of framebuffer
 		 * @return Creation status
 		 */
 		virtual GLenum createFBO(GLuint&, GLuint&, GLuint&, int, int)
 		{ return GL_FRAMEBUFFER_UNSUPPORTED; }
 		/// remove objects
 		/**
-		 * @param[in] framebuffer Framebuffer name
-		 * @param[in] depthbuffer Depthbuffer name
-		 * @param[in] img         Texture name
+		 * @param[in] framebuffer   Framebuffer name
+		 * @param[in] stencilbuffer Stencilbuffer name
+		 * @param[in] img           Texture name
 		 */
 		virtual void deleteFBO(GLuint, GLuint, GLuint) {}
 		virtual void bindFBO(GLuint) {}
 	};
 
 	struct FramebufferStrategyGL3 : public FramebufferStrategy {
-		virtual GLenum createFBO(GLuint& framebuffer, GLuint& depthbuffer, GLuint& img, int width, int height)
+		virtual GLenum createFBO(GLuint& framebuffer, GLuint& stencilbuffer,  GLuint& img, int width, int height)
 		{
 			// get currently bound fbo to reset to it later
 			GLint current_fbo;
 			glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &current_fbo);
 
-			// generate depth buffer
-			glGenRenderbuffers(1, &depthbuffer);
-			glBindRenderbuffer(GL_RENDERBUFFER, depthbuffer);
-			glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, width, height);
-			glBindRenderbuffer(GL_RENDERBUFFER, 0);
+			// create framebuffer
+			glGenFramebuffers(1, &framebuffer);
+			glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
+
+			// create stencil buffer
+			glGenRenderbuffers(1, &stencilbuffer);
+			glBindRenderbuffer(GL_RENDERBUFFER, stencilbuffer);
+			glRenderbufferStorage(GL_RENDERBUFFER, GL_STENCIL_INDEX, width, height);
+			glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
+					GL_RENDERBUFFER, stencilbuffer);
 
 			// generate texture save target
 			glGenTextures(1, &img);
@@ -56,24 +61,21 @@ namespace opengl
 			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height,
 					0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 			glBindTexture(GL_TEXTURE_2D, 0);
-
-			// create framebuffer
-			glGenFramebuffers(1, &framebuffer);
-			glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
 			glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 					GL_TEXTURE_2D, img, 0);
-			glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
-					GL_RENDERBUFFER, depthbuffer);
+
+			// check status
 			GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
 
 			// unbind framebuffer
+			glBindRenderbuffer(GL_RENDERBUFFER, 0);
 			glBindFramebuffer(GL_FRAMEBUFFER, (GLuint)current_fbo);
 			return status;
 		}
-		virtual void deleteFBO(GLuint framebuffer, GLuint depthbuffer, GLuint img)
+		virtual void deleteFBO(GLuint framebuffer, GLuint stencilbuffer,  GLuint img)
 		{
 			glDeleteTextures(1, &img);
-			glDeleteRenderbuffers(1, &depthbuffer);
+			glDeleteRenderbuffers(1, &stencilbuffer);
 			glDeleteFramebuffers(1, &framebuffer);
 		}
 
@@ -85,16 +87,21 @@ namespace opengl
 
 	struct FramebufferStrategyEXT : public FramebufferStrategy {
 
-		virtual GLenum createFBO(GLuint& framebuffer, GLuint& depthbuffer, GLuint& img, int width, int height)
+		virtual GLenum createFBO(GLuint& framebuffer, GLuint& stencilbuffer, GLuint& img, int width, int height)
 		{
 			GLint current_fbo;
 			glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING_EXT, &current_fbo);
 
-			// generate depth buffer
-			glGenRenderbuffersEXT(1, &depthbuffer);
-			glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, depthbuffer);
-			glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT16, width, height);
-			glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0);
+			// create framebuffer
+			glGenFramebuffersEXT(1, &framebuffer);
+			glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer);
+
+			// create stencil buffer
+			glGenRenderbuffersEXT(1, &stencilbuffer);
+			glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, stencilbuffer);
+			glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_STENCIL_INDEX, width, height);
+			glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT,
+					GL_RENDERBUFFER_EXT, stencilbuffer);
 
 			// generate texture save target
 			glGenTextures(1, &img);
@@ -104,25 +111,22 @@ namespace opengl
 			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height,
 					0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 			glBindTexture(GL_TEXTURE_2D, 0);
-
-			// create framebuffer
-			glGenFramebuffersEXT(1, &framebuffer);
-			glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer);
 			glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 					GL_TEXTURE_2D, img, 0);
-			glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
-					GL_RENDERBUFFER_EXT, depthbuffer);
+
+			// check status
 			GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
 
 			// unbind framebuffer
+			glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0);
 			glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, (GLuint)current_fbo);
 			return status;
 		}
 
-		virtual void deleteFBO(GLuint framebuffer, GLuint depthbuffer, GLuint img)
+		virtual void deleteFBO(GLuint framebuffer, GLuint stencilbuffer, GLuint img)
 		{
 			glDeleteTextures(1, &img);
-			glDeleteRenderbuffersEXT(1, &depthbuffer);
+			glDeleteRenderbuffersEXT(1, &stencilbuffer);
 			glDeleteFramebuffersEXT(1, &framebuffer);
 		}
 
@@ -213,9 +217,8 @@ namespace opengl
 			current->stopGrab();
 
 		// bind buffer and clear screen
-		glPushAttrib(GL_VIEWPORT_BIT | GL_DEPTH_BUFFER_BIT | GL_TRANSFORM_BIT);
+		glPushAttrib(GL_VIEWPORT_BIT | GL_TRANSFORM_BIT);
 		strategy->bindFBO(fbo);
-		glClear(GL_DEPTH_BUFFER_BIT);
 		glViewport(0, 0, width, height);
 		
 		// Reset the projection matrix
@@ -366,7 +369,7 @@ namespace opengl
 
 	bool Canvas::loadVolatile()
 	{
-		status = strategy->createFBO(fbo, depthbuffer, img, width, height);
+		status = strategy->createFBO(fbo, stencilbuffer, img, width, height);
 		if (status != GL_FRAMEBUFFER_COMPLETE)
 			return false;
 
@@ -382,7 +385,7 @@ namespace opengl
 	{
 		settings.filter = getFilter();
 		settings.wrap   = getWrap();
-		strategy->deleteFBO(fbo, depthbuffer, img);
+		strategy->deleteFBO(fbo, stencilbuffer, img);
 	}
 
 	int Canvas::getWidth()

src/modules/graphics/opengl/Canvas.h

@@ -77,7 +77,7 @@ namespace opengl
 		GLsizei width;
 		GLsizei height;
 		GLuint fbo;
-		GLuint depthbuffer;
+		GLuint stencilbuffer;
 		GLuint img;
 
 		vertex vertices[4];

src/modules/graphics/opengl/wrap_Graphics.cpp

@@ -169,9 +169,6 @@ namespace opengl
 
 	static int setStencil(lua_State * L, bool invert)
 	{
-		// stencils require the default fb to work properly
-		Canvas::TemporaryUnbinder unbinder;
-
 		// no argument -> clear mask
 		if (lua_isnoneornil(L, 1)) {
 			instance->discardStencil();