Attachment 120980 Details for Bug 93676 – parts of the rendering set up

parts of the rendering set up

fbo_rendering.c (text/plain), 9.03 KB, created by Clive McCarthy on 2016-01-12 06:39:52 UTC

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Creator: Clive McCarthy

Created: 2016-01-12 06:39:52 UTC

Size: 9.03 KB

patch

obsolete

>/*------------------------------------------------------------------------------
>GL_READ_FRAMEBUFFER, or GL_DRAW_FRAMEBUFFER.
>allow you to bind an FBO so that
>reading commands (glReadPixels, glCopyPixels, etc) and
>writing commands (any command of the form glDraw*)
>can happen to two different buffers.
>	width  = display_mode->width;
>	height = display_mode->height;
>
>------------------------------------------------------------------------------*/
>void render_to_fbo(void)
>{
>	GLuint frame_buffer_name = 0, render_buffer_name = 0;
>	int width, height;
>
>	// make the FBO as big as the screen
>	width  = glutGet(GLUT_SCREEN_WIDTH);
>	height = glutGet(GLUT_SCREEN_HEIGHT);
>
>	// create a framebuffer object
>	glGenFramebuffers(1, &frame_buffer_name);
>
>	// GL_FRAMEBUFFER target simply sets both the read and the write to
>	// the same FBO.
>	glBindFramebuffer(GL_FRAMEBUFFER, frame_buffer_name);
>	if(!glIsFramebuffer(frame_buffer_name))
>	{
>		program_error(__FILE__, __LINE__, __FUNC__,
>			"glIsFramebuffer failed (frame_buffer_name=%d)",
>			frame_buffer_name);
>	}
>
>	// create a renderbuffer object to store the image
>	glGenRenderbuffers(1, &render_buffer_name);
>	glBindRenderbuffer(GL_RENDERBUFFER, render_buffer_name);
>	if(!glIsRenderbuffer(render_buffer_name))
>	{
>		program_error(__FILE__, __LINE__, __FUNC__,
>			"glIsRenderbuffer failed (render_buffer_name=%d)",
>			render_buffer_name);
>	}
>
>	// We are guaranteed to be able to have at least color attachment 0
>	// attach the renderbuffer to GL_COLOR_ATTACHMENT0
>	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
>		GL_RENDERBUFFER, render_buffer_name);
>	glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA4, width, height);
>
>	check_framebuffer_completeness_status(__FILE__, __LINE__, __FUNC__);
>	OpenGL_error_check(__FILE__, __LINE__, __FUNC__);
>	set_OpenGL_viewport(width, height);
>
>	glReadBuffer(GL_COLOR_ATTACHMENT0);
>	glDrawBuffer(GL_COLOR_ATTACHMENT0);
>
>	glEnable(GL_BLEND);					// enable blending
>	glEnable(GL_TEXTURE_2D);
>	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
>	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
>	glClearColor(1.0, 1.0, 1.0, 1.0);
>	glClear(GL_COLOR_BUFFER_BIT);
>
>	program_information
>	(
>		__FILE__, __LINE__, __FUNC__,
>		"FBO rendering to %dpx X %dpx buffer", width, height
>	);
>	OpenGL_error_check(__FILE__, __LINE__, __FUNC__);
>}
>/*------------------------------------------------------------------------------
>glBlitFramebuffer
>
>transfers a rectangle of pixel values from one region
>of the read framebuffer to another region in the draw framebuffer. mask
>is the bitwise OR of a number of values indicating which buffers are to
>be copied.
>
>The values are GL_COLOR_BUFFER_BIT, GL_DEPTH_BUFFER_BIT, and
>GL_STENCIL_BUFFER_BIT. The pixels corresponding to these buffers are
>copied from the source rectangle bounded by the locations (srcX0; srcY0)
>and (srcX1; srcY1) to the destination rectangle bounded by the locations
>(dstX0; dstY0) and (dstX1; dstY1). The lower bounds of the rectangle are
>inclusive, while the upper bounds are exclusive.
>
>Create and FBO:
>set the draw framebuffer to be the FBO
>	glDrawBuffer(GL_COLOR_ATTACHMENT0);
>set the read framebuffer to be the FBO
>	glReadBuffer(GL_COLOR_ATTACHMENT0);
>
>render the paint strokes to the FBO
>pixel reads will come from the FBO
>
>The name comes from BLIT, which is not an acronym
>A typical use for a blitter is the movement of a bitmap
>
>glDebugMessageCallback requires OpenGL 4.3
>------------------------------------------------------------------------------*/
>void blit_fbo_to_front_buffer(void)
>{
>	GLint frame_buffer_name;
>	GLint viewport[4];
>
>	glGetIntegerv(GL_VIEWPORT, viewport);
>	glGetIntegerv(GL_FRAMEBUFFER_BINDING, &frame_buffer_name);
>	// change draw framebuffer to be the front buffer
>	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
>	glDrawBuffer(GL_FRONT);
>	//OpenGL_error_check(__FILE__, __LINE__, __FUNC__);
>
>	glBlitFramebuffer		// copy FBO data to the back buffer
>	(
>		viewport[0],  viewport[1],
>		viewport[2] + viewport[0],
>		viewport[3] + viewport[1],
>		viewport[0],  viewport[1],
>		viewport[2] + viewport[0],
>		viewport[3] + viewport[1],
>		GL_COLOR_BUFFER_BIT,
>		GL_NEAREST
>	);
>
>	// restore draw framebuffer to be the FBO
>	glBindFramebuffer(GL_FRAMEBUFFER, frame_buffer_name);
>	glDrawBuffer(GL_COLOR_ATTACHMENT0);
>}
>/*------------------------------------------------------------------------------
>
>#define USE_INTEL_FBO
>------------------------------------------------------------------------------*/
>void select_rendering_mode_for_mesa_version(int argc, char **argv)
>{
>
>	if(cpuid_without_stepping() == 0x1067) // U7300
>	{
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"U7300 with GM45");
>
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"glutSwapBuffers GLUT_DOUBLE");
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>		glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
>		glDrawBuffer(GL_FRONT_AND_BACK);
>		glutDisplayFunc(glutSwapBuffers);	// set the glut callback
>	}
>	else
>	if(strcasestr(get_opengl_version_string(), "11.2.0") != NULL)
>	{
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"Mesa 11.2.0 installed");
>#ifdef USE_INTEL_FBO
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"blit_fbo_to_front_buffer GLUT_SINGLE artefacts? = yes");
>
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>		glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE);
>		render_to_fbo();
>		glutDisplayFunc(blit_fbo_to_front_buffer);	// set the glut callback
>#else
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"glutSwapBuffers GLUT_DOUBLE");
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>		glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
>		glDrawBuffer(GL_FRONT_AND_BACK);
>		glutDisplayFunc(glutSwapBuffers);	// set the glut callback
>#endif
>	}
>	else
>	if(strcasestr(get_opengl_version_string(), "11.1.0-devel") != NULL)
>	{
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"Mesa 11.1.0 installed");
>
>#ifdef USE_INTEL_FBO
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"blit_fbo_to_front_buffer GLUT_SINGLE artefacts?");
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>		glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE);
>		render_to_fbo();
>		glutDisplayFunc(blit_fbo_to_front_buffer);	// set the glut callback
>#else
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"glutSwapBuffers GLUT_DOUBLE");
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>		glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
>		glDrawBuffer(GL_FRONT_AND_BACK);
>		glutDisplayFunc(glutSwapBuffers);	// set the glut callback
>#endif
>	}
>	else
>	if(strcasestr(get_opengl_version_string(), "10.6.3") != NULL)
>	{
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"Mesa 10.6.3 installed");
>
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"glutSwapBuffers GLUT_DOUBLE");
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>		glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
>		glutDisplayFunc(glutSwapBuffers);	// set the glut callback
>		glDrawBuffer(GL_FRONT_AND_BACK);
>	}
>	else
>	if(strcasestr(get_opengl_version_string(), "10.1.0") != NULL)
>	{
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"Mesa 10.1.0 installed");
>
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"glutSwapBuffers GLUT_SINGLE");
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>		glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE);
>		glutDisplayFunc(glutSwapBuffers);	// set the glut callback
>		glDrawBuffer(GL_FRONT);
>	}
>	else
>	{
>		program_warning(__FILE__, __LINE__, __FUNC__,
>			"Did NOT find a known Mesa driver installation %s",
>			get_opengl_version_string());
>
>#ifdef USE_INTEL_FBO
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"blit_fbo_to_front_buffer GLUT_SINGLE");
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>		glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE);
>		render_to_fbo();
>		glutDisplayFunc(blit_fbo_to_front_buffer);	// set the glut callback
>#else
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"glutSwapBuffers GLUT_DOUBLE");
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>		glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
>		glDrawBuffer(GL_FRONT_AND_BACK);
>		glutDisplayFunc(glutSwapBuffers);	// set the glut callback
>#endif
>	}
>}
>/*------------------------------------------------------------------------------
>	This will set the rendering mode based on the platform's GPU and driver
>
>	Rendering is either done via swapbuffers() or by render_to_fbo()
>
>------------------------------------------------------------------------------*/
>void set_OpenGL_rendering_mode(int argc, char **argv)
>{
>	if(strcasestr(get_opengl_version_string(), "Mesa") != NULL)
>	{
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"using Mesa driver");
>		select_rendering_mode_for_mesa_version(argc, argv);
>	}
>	else
>	{
>		program_information(__FILE__, __LINE__, __FUNC__,
>			"using non-Mesa driver");
>		glutInit(&argc, argv);
>		glutCreateWindow("FourteenthStreetStudio");
>
>		// any configuration with an Nvida GPU
>		glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE);
>		render_to_fbo();
>		glutDisplayFunc(blit_fbo_to_front_buffer);	// set the glut callback
>	}
>
>	OpenGL_error_check(__FILE__, __LINE__, __FUNC__);
>}
>

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Attachments on bug 93676: 120976 | 120977 | 120978 | 120979 | 120980 | 120983

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