Fix models rendering incorrectly when using rtt

Author: MjnMixael

code/graphics/opengl/gropengltexture.cpp

@@ -1866,10 +1866,10 @@ int opengl_make_render_target( int handle, int *w, int *h, int *bpp, int *mm_lvl
 
 	GL_state.Texture.Enable(0);
 
-	// render buffer
-//	glGenRenderbuffers(1, &new_fbo.renderbuffer_id);
-//	glBindRenderbuffer(GL_RENDERBUFFER, new_fbo.renderbuffer_id);
-//	glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, *w, *h);
+	// render buffer (depth)
+	glGenRenderbuffers(1, &new_fbo->renderbuffer_id);
+	glBindRenderbuffer(GL_RENDERBUFFER, new_fbo->renderbuffer_id);
+	glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, *w, *h);
 	glBindRenderbuffer(GL_RENDERBUFFER, 0);
 
 	// frame buffer
@@ -1883,7 +1883,7 @@ int opengl_make_render_target( int handle, int *w, int *h, int *bpp, int *mm_lvl
 		glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, ts->texture_id, 0, 0);
 	}
 
-//	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, new_fbo.renderbuffer_id);
+	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, new_fbo->renderbuffer_id);
 
 	if ( opengl_check_framebuffer() ) {
 		// Oops!!  reset everything and then bail
@@ -1898,7 +1898,10 @@ int opengl_make_render_target( int handle, int *w, int *h, int *bpp, int *mm_lvl
 
 		glDeleteFramebuffers(1, &new_fbo->framebuffer_id);
 
-	//	glDeleteRenderbuffersEXT(1, &new_fbo.renderbuffer_id);
+		if (new_fbo->renderbuffer_id) {
+			glDeleteRenderbuffers(1, &new_fbo->renderbuffer_id);
+			new_fbo->renderbuffer_id = 0;
+		}
 
 		opengl_set_texture_target();
 		opengl_free_fbo_slot(fbo_id);

code/graphics/opengl/gropengltnl.cpp

@@ -822,7 +822,10 @@ void opengl_tnl_set_model_material(model_material *material_info)
 	opengl_tnl_set_material(material_info, false, false);
 
 	if ( GL_state.CullFace() ) {
-		GL_state.FrontFaceValue(GL_CW);
+		// Model rendering uses CW front faces in the default backbuffer path.
+		// Render-to-texture flips the projection vertically, which flips winding,
+		// so we must invert the front-face definition there.
+		GL_state.FrontFaceValue(gr_screen.rendering_to_texture != -1 ? GL_CCW : GL_CW);
 	}
 
 	gr_set_center_alpha(material_info->get_center_alpha());