renderer: add r_framebuffer_copy

src/renderer/api.c

@@ -597,6 +597,10 @@ void r_framebuffer_clear(Framebuffer *fb, BufferKindFlags flags, const Color *co
 	B.framebuffer_clear(fb, flags, colorval, depthval);
 }
 
+void r_framebuffer_copy(Framebuffer *dst, Framebuffer *src, BufferKindFlags flags) {
+	B.framebuffer_copy(dst, src, flags);
+}
+
 void r_framebuffer_viewport(Framebuffer *fb, float x, float y, float w, float h) {
 	r_framebuffer_viewport_rect(fb, (FloatRect) { x, y, w, h });
 }

src/renderer/api.h

@@ -769,6 +769,7 @@ void r_framebuffer_viewport_rect(Framebuffer *fb, FloatRect viewport);
 void r_framebuffer_viewport_current(Framebuffer *fb, FloatRect *viewport) attr_nonnull(2);
 void r_framebuffer_destroy(Framebuffer *fb) attr_nonnull(1);
 void r_framebuffer_clear(Framebuffer *fb, BufferKindFlags flags, const Color *colorval, float depthval);
+void r_framebuffer_copy(Framebuffer *dst, Framebuffer *src, BufferKindFlags flags) attr_nonnull_all;
 IntExtent r_framebuffer_get_size(Framebuffer *fb);
 
 void r_framebuffer(Framebuffer *fb);

src/renderer/common/backend.h

@@ -90,6 +90,7 @@ typedef struct RendererFuncs {
 	FramebufferAttachmentQueryResult (*framebuffer_query_attachment)(Framebuffer *framebuffer, FramebufferAttachment attachment);
 	void (*framebuffer_outputs)(Framebuffer *framebuffer, FramebufferAttachment config[FRAMEBUFFER_MAX_OUTPUTS], uint8_t write_mask);
 	void (*framebuffer_clear)(Framebuffer *framebuffer, BufferKindFlags flags, const Color *colorval, float depthval);
+	void (*framebuffer_copy)(Framebuffer *dst, Framebuffer *src, BufferKindFlags flags);
 	IntExtent (*framebuffer_get_size)(Framebuffer *framebuffer);
 
 	void (*framebuffer)(Framebuffer *framebuffer);

src/renderer/gl33/framebuffer.c

@@ -198,6 +198,27 @@ void gl33_framebuffer_clear(Framebuffer *framebuffer, BufferKindFlags flags, con
 	r_framebuffer(fb_saved);
 }
 
+void gl33_framebuffer_copy(Framebuffer *dst, Framebuffer *src, BufferKindFlags flags) {
+	GLuint glflags = buffer_flags_to_gl(flags);
+
+	r_flush_sprites();
+
+	IntExtent size = r_framebuffer_get_size(dst);
+	GLint X0 = 0;
+	GLint X1 = size.w;
+	GLint Y0 = 0;
+	GLint Y1 = size.h;
+
+	Framebuffer *fb_saved = r_framebuffer_current();
+	r_framebuffer(dst);
+	gl33_sync_framebuffer();
+	gl33_sync_scissor();
+	// TODO track this?
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, src->gl_fbo);
+	glBlitFramebuffer(X0, Y0, X1, Y1, X0, Y0, X1, Y1, glflags, GL_NEAREST);
+	r_framebuffer(fb_saved);
+}
+
 IntExtent gl33_framebuffer_get_effective_size(Framebuffer *framebuffer) {
 	// According to the OpenGL wiki:
 	// "The effective size of the FBO is the intersection of all of the sizes of the bound images (ie: the smallest in each dimension)."

src/renderer/gl33/framebuffer.h

@@ -32,6 +32,7 @@ void gl33_framebuffer_outputs(Framebuffer *framebuffer, FramebufferAttachment co
 void gl33_framebuffer_destroy(Framebuffer *framebuffer);
 void gl33_framebuffer_taint(Framebuffer *framebuffer);
 void gl33_framebuffer_clear(Framebuffer *framebuffer, BufferKindFlags flags, const Color *colorval, float depthval);
+void gl33_framebuffer_copy(Framebuffer *dst, Framebuffer *src, BufferKindFlags flags);
 IntExtent gl33_framebuffer_get_effective_size(Framebuffer *framebuffer);
 void gl33_framebuffer_set_debug_label(Framebuffer *fb, const char *label);
 const char *gl33_framebuffer_get_debug_label(Framebuffer* fb);

src/renderer/gl33/gl33.c

@@ -1500,6 +1500,7 @@ RendererBackend _r_backend_gl33 = {
 		.framebuffer = gl33_framebuffer,
 		.framebuffer_current = gl33_framebuffer_current,
 		.framebuffer_clear = gl33_framebuffer_clear,
+		.framebuffer_copy = gl33_framebuffer_copy,
 		.framebuffer_get_size = gl33_framebuffer_get_size,
 		.vertex_buffer_create = gl33_vertex_buffer_create,
 		.vertex_buffer_set_debug_label = gl33_vertex_buffer_set_debug_label,

src/renderer/null/null.c

@@ -130,6 +130,7 @@ static void null_framebuffer_viewport_current(Framebuffer *framebuffer, FloatRec
 static void null_framebuffer(Framebuffer *framebuffer) { }
 static Framebuffer* null_framebuffer_current(void) { return (void*)&placeholder; }
 static void null_framebuffer_clear(Framebuffer *framebuffer, BufferKindFlags flags, const Color *colorval, float depthval) { }
+static void null_framebuffer_copy(Framebuffer *dst, Framebuffer *src, BufferKindFlags flags) { }
 static IntExtent null_framebuffer_get_size(Framebuffer *framebuffer) { return (IntExtent) { 64, 64 }; }
 
 static int64_t null_vertex_buffer_stream_seek(SDL_RWops *rw, int64_t offset, int whence) { return 0; }
@@ -254,6 +255,7 @@ RendererBackend _r_backend_null = {
 		.framebuffer = null_framebuffer,
 		.framebuffer_current = null_framebuffer_current,
 		.framebuffer_clear = null_framebuffer_clear,
+		.framebuffer_copy = null_framebuffer_copy,
 		.framebuffer_get_size = null_framebuffer_get_size,
 		.vertex_buffer_create = null_vertex_buffer_create,
 		.vertex_buffer_get_debug_label = null_vertex_buffer_get_debug_label,