GPUFramebuffer: Refactor (Part 2)

This refactor modernise the use of framebuffers.
It also touches a lot of files so breaking down changes we have:
 - GPUTexture: Allow textures to be attached to more than one GPUFrameBuffer.
   This allows to create and configure more FBO without the need to attach
   and detach texture at drawing time.
 - GPUFrameBuffer: The wrapper starts to mimic opengl a bit closer. This
   allows to configure the framebuffer inside a context other than the one
   that will be rendering the framebuffer. We do the actual configuration
   when binding the FBO. We also Keep track of config validity and save
   drawbuffers state in the FBO. We remove the different bind/unbind
   functions. These make little sense now that we have separate contexts.
 - DRWFrameBuffer: We replace DRW_framebuffer functions by GPU_framebuffer
   ones to avoid another layer of abstraction. We move the DRW convenience
   functions to GPUFramebuffer instead and even add new ones. The MACRO
   GPU_framebuffer_ensure_config is pretty much all you need to create and
   config a GPUFramebuffer.
 - DRWTexture: Due to the removal of DRWFrameBuffer, we needed to create
   functions to create textures for thoses framebuffers. Pool textures are
   now using default texture parameters for the texture type asked.
 - DRWManager: Make sure no framebuffer object is bound when doing cache
   filling.
 - GPUViewport: Add new color_only_fb and depth_only_fb along with FB API
   usage update. This let draw engines render to color/depth only target
   and without the need to attach/detach textures.
 - WM_window: Assert when a framebuffer is bound when changing context.
   This balance the fact we are not track ogl context inside GPUFramebuffer.
 - Eevee, Clay, Mode engines: Update to new API. This comes with a lot of
   code simplification.

This also come with some cleanups in some engine codes.

1 files changed, 38 insertions, 56 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_screen_raytrace.c b/source/blender/draw/engines/eevee/eevee_screen_raytrace.c
index 96d560688f3..7a856870eb3 100644
--- a/source/blender/draw/engines/eevee/eevee_screen_raytrace.c
+++ b/source/blender/draw/engines/eevee/eevee_screen_raytrace.c
@@ -124,14 +124,15 @@ int EEVEE_screen_raytrace_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 		const bool use_refraction = BKE_collection_engine_property_value_get_bool(props, "ssr_refraction");
 
 		if (use_refraction) {
-			DRWFboTexture tex = {&txl->refract_color, DRW_TEX_RGB_11_11_10, DRW_TEX_FILTER | DRW_TEX_MIPMAP};
+			/* TODO: Opti: Could be shared. */
+			DRW_texture_ensure_fullscreen_2D(&txl->refract_color, DRW_TEX_RGB_11_11_10, DRW_TEX_FILTER | DRW_TEX_MIPMAP);
 
-			DRW_framebuffer_init(&fbl->refract_fb, &draw_engine_eevee_type,
-			                     (int)viewport_size[0], (int)viewport_size[1],
-			                     &tex, 1);
+			GPU_framebuffer_ensure_config(&fbl->refract_fb, {
+				GPU_ATTACHMENT_NONE,
+				GPU_ATTACHMENT_TEXTURE(txl->refract_color)
+			});
 		}
 
-		bool prev_trace_full = effects->reflection_trace_full;
 		effects->reflection_trace_full = !BKE_collection_engine_property_value_get_bool(props, "ssr_halfres");
 		common_data->ssr_thickness = BKE_collection_engine_property_value_get_float(props, "ssr_thickness");
 		common_data->ssr_border_fac = BKE_collection_engine_property_value_get_float(props, "ssr_border_fade");
@@ -144,47 +145,39 @@ int EEVEE_screen_raytrace_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 			common_data->ssr_firefly_fac = FLT_MAX;
 		}
 
-		if (prev_trace_full != effects->reflection_trace_full) {
-			DRW_TEXTURE_FREE_SAFE(txl->ssr_hit_output);
-		}
-
 		const int divisor = (effects->reflection_trace_full) ? 1 : 2;
 		int tracing_res[2] = {(int)viewport_size[0] / divisor, (int)viewport_size[1] / divisor};
+		int size_fs[2] = {(int)viewport_size[0], (int)viewport_size[1]};
 		const bool high_qual_input = true; /* TODO dither low quality input */
+		const DRWTextureFormat format = (high_qual_input) ? DRW_TEX_RGBA_16 : DRW_TEX_RGBA_8;
 
 		/* MRT for the shading pass in order to output needed data for the SSR pass. */
-		/* TODO create one texture layer per lobe */
-		if (txl->ssr_specrough_input == NULL) {
-			DRWTextureFormat specrough_format = (high_qual_input) ? DRW_TEX_RGBA_16 : DRW_TEX_RGBA_8;
-			txl->ssr_specrough_input = DRW_texture_create_2D((int)viewport_size[0], (int)viewport_size[1],
-			                                                 specrough_format, 0, NULL);
-		}
+		effects->ssr_specrough_input = DRW_texture_pool_query_2D(size_fs[0], size_fs[1], format,
+		                                                         &draw_engine_eevee_type);
 
-		/* Reattach textures to the right buffer (because we are alternating between buffers) */
-		/* TODO multiple FBO per texture!!!! */
-		DRW_framebuffer_texture_detach(txl->ssr_specrough_input);
-		DRW_framebuffer_texture_attach(fbl->main, txl->ssr_specrough_input, 2, 0);
+		GPU_framebuffer_texture_attach(fbl->main_fb, effects->ssr_specrough_input, 2, 0);
 
 		/* Raytracing output */
-		/* (AMD or Intel) For some reason DRW_TEX_TEMP with DRW_TEX_RG_16I
-		 * creates problems when toggling ssr_halfres. Texture is not read correctly (black output).
-		 * So using a persistent buffer instead. */
-		DRWFboTexture tex_output[2] = {{&txl->ssr_hit_output, DRW_TEX_RG_16I, 0},
-		                               {&stl->g_data->ssr_pdf_output, DRW_TEX_R_16, DRW_TEX_TEMP}};
+		effects->ssr_hit_output = DRW_texture_pool_query_2D(tracing_res[0], tracing_res[1], DRW_TEX_RG_16I,
+		                                                    &draw_engine_eevee_type);
+		effects->ssr_pdf_output = DRW_texture_pool_query_2D(tracing_res[0], tracing_res[1], DRW_TEX_R_16,
+		                                                    &draw_engine_eevee_type);
 
-		DRW_framebuffer_init(&fbl->screen_tracing_fb, &draw_engine_eevee_type,
-		                     tracing_res[0], tracing_res[1],
-		                     tex_output, 2);
+		GPU_framebuffer_ensure_config(&fbl->screen_tracing_fb, {
+			GPU_ATTACHMENT_NONE,
+			GPU_ATTACHMENT_TEXTURE(effects->ssr_hit_output),
+			GPU_ATTACHMENT_TEXTURE(effects->ssr_pdf_output)
+		});
 
 		/* Enable double buffering to be able to read previous frame color */
 		return EFFECT_SSR | EFFECT_NORMAL_BUFFER | EFFECT_DOUBLE_BUFFER | ((use_refraction) ? EFFECT_REFRACT : 0);
 	}
 
 	/* Cleanup to release memory */
-	DRW_TEXTURE_FREE_SAFE(txl->ssr_specrough_input);
-	DRW_TEXTURE_FREE_SAFE(txl->ssr_hit_output);
-	DRW_FRAMEBUFFER_FREE_SAFE(fbl->screen_tracing_fb);
-	stl->g_data->ssr_pdf_output = NULL;
+	GPU_FRAMEBUFFER_FREE_SAFE(fbl->screen_tracing_fb);
+	effects->ssr_specrough_input = NULL;
+	effects->ssr_hit_output = NULL;
+	effects->ssr_pdf_output = NULL;
 
 	return 0;
 }
@@ -221,8 +214,8 @@ void EEVEE_screen_raytrace_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *v
 		psl->ssr_raytrace = DRW_pass_create("SSR Raytrace", DRW_STATE_WRITE_COLOR);
 		DRWShadingGroup *grp = DRW_shgroup_create(trace_shader, psl->ssr_raytrace);
 		DRW_shgroup_uniform_buffer(grp, "depthBuffer", &e_data.depth_src);
-		DRW_shgroup_uniform_buffer(grp, "normalBuffer", &txl->ssr_normal_input);
-		DRW_shgroup_uniform_buffer(grp, "specroughBuffer", &txl->ssr_specrough_input);
+		DRW_shgroup_uniform_buffer(grp, "normalBuffer", &effects->ssr_normal_input);
+		DRW_shgroup_uniform_buffer(grp, "specroughBuffer", &effects->ssr_specrough_input);
 		DRW_shgroup_uniform_buffer(grp, "maxzBuffer", &txl->maxzbuffer);
 		DRW_shgroup_uniform_buffer(grp, "planarDepth", &vedata->txl->planar_depth);
 		DRW_shgroup_uniform_texture(grp, "utilTex", EEVEE_materials_get_util_tex());
@@ -236,13 +229,13 @@ void EEVEE_screen_raytrace_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *v
 		psl->ssr_resolve = DRW_pass_create("SSR Resolve", DRW_STATE_WRITE_COLOR | DRW_STATE_ADDITIVE);
 		grp = DRW_shgroup_create(resolve_shader, psl->ssr_resolve);
 		DRW_shgroup_uniform_buffer(grp, "depthBuffer", &e_data.depth_src);
-		DRW_shgroup_uniform_buffer(grp, "normalBuffer", &txl->ssr_normal_input);
-		DRW_shgroup_uniform_buffer(grp, "specroughBuffer", &txl->ssr_specrough_input);
+		DRW_shgroup_uniform_buffer(grp, "normalBuffer", &effects->ssr_normal_input);
+		DRW_shgroup_uniform_buffer(grp, "specroughBuffer", &effects->ssr_specrough_input);
 		DRW_shgroup_uniform_buffer(grp, "probeCubes", &sldata->probe_pool);
 		DRW_shgroup_uniform_buffer(grp, "probePlanars", &vedata->txl->planar_pool);
 		DRW_shgroup_uniform_buffer(grp, "planarDepth", &vedata->txl->planar_depth);
-		DRW_shgroup_uniform_buffer(grp, "hitBuffer", &vedata->txl->ssr_hit_output);
-		DRW_shgroup_uniform_buffer(grp, "pdfBuffer", &stl->g_data->ssr_pdf_output);
+		DRW_shgroup_uniform_buffer(grp, "hitBuffer", &effects->ssr_hit_output);
+		DRW_shgroup_uniform_buffer(grp, "pdfBuffer", &effects->ssr_pdf_output);
 		DRW_shgroup_uniform_buffer(grp, "prevColorBuffer", &txl->color_double_buffer);
 		DRW_shgroup_uniform_block(grp, "probe_block", sldata->probe_ubo);
 		DRW_shgroup_uniform_block(grp, "planar_block", sldata->planar_ubo);
@@ -250,7 +243,7 @@ void EEVEE_screen_raytrace_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *v
 		DRW_shgroup_uniform_int(grp, "neighborOffset", &effects->ssr_neighbor_ofs, 1);
 		if ((effects->enabled_effects & EFFECT_GTAO) != 0) {
 			DRW_shgroup_uniform_texture(grp, "utilTex", EEVEE_materials_get_util_tex());
-			DRW_shgroup_uniform_buffer(grp, "horizonBuffer", &vedata->txl->gtao_horizons);
+			DRW_shgroup_uniform_buffer(grp, "horizonBuffer", &effects->gtao_horizons);
 		}
 
 		DRW_shgroup_call_add(grp, quad, NULL);
@@ -265,12 +258,11 @@ void EEVEE_refraction_compute(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *v
 	EEVEE_EffectsInfo *effects = stl->effects;
 
 	if ((effects->enabled_effects & EFFECT_REFRACT) != 0) {
-		DRW_framebuffer_texture_attach(fbl->refract_fb, txl->refract_color, 0, 0);
-		DRW_framebuffer_blit(fbl->main, fbl->refract_fb, false, false);
-		EEVEE_downsample_buffer(vedata, fbl->downsample_fb, txl->refract_color, 9);
+		GPU_framebuffer_blit(fbl->main_fb, 0, fbl->refract_fb, 0, GPU_COLOR_BIT);
+		EEVEE_downsample_buffer(vedata, txl->refract_color, 9);
 
 		/* Restore */
-		DRW_framebuffer_bind(fbl->main);
+		GPU_framebuffer_bind(fbl->main_fb);
 	}
 }
 
@@ -287,15 +279,12 @@ void EEVEE_reflection_compute(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *v
 		e_data.depth_src = dtxl->depth;
 
 		DRW_stats_group_start("SSR");
-		DRW_framebuffer_texture_attach(fbl->screen_tracing_fb, stl->g_data->ssr_pdf_output, 1, 0);
-		DRW_framebuffer_bind(fbl->screen_tracing_fb);
 
 		/* Raytrace. */
+		GPU_framebuffer_bind(fbl->screen_tracing_fb);
 		DRW_draw_pass(psl->ssr_raytrace);
 
-		DRW_framebuffer_texture_detach(stl->g_data->ssr_pdf_output);
-
-		EEVEE_downsample_buffer(vedata, fbl->downsample_fb, txl->color_double_buffer, 9);
+		EEVEE_downsample_buffer(vedata, txl->color_double_buffer, 9);
 
 		/* Resolve at fullres */
 		int sample = (DRW_state_is_image_render()) ? effects->taa_render_sample : effects->taa_current_sample;
@@ -320,18 +309,11 @@ void EEVEE_reflection_compute(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *v
 				effects->ssr_halfres_ofs[1] = 1;
 				break;
 		}
-		DRW_framebuffer_texture_detach(dtxl->depth);
-		DRW_framebuffer_texture_detach(txl->ssr_normal_input);
-		DRW_framebuffer_texture_detach(txl->ssr_specrough_input);
-		DRW_framebuffer_bind(fbl->main);
+		GPU_framebuffer_bind(fbl->main_color_fb);
 		DRW_draw_pass(psl->ssr_resolve);
 
 		/* Restore */
-		DRW_framebuffer_texture_attach(fbl->main, dtxl->depth, 0, 0);
-		DRW_framebuffer_texture_attach(fbl->main, txl->ssr_normal_input, 1, 0);
-		DRW_framebuffer_texture_attach(fbl->main, txl->ssr_specrough_input, 2, 0);
-		DRW_framebuffer_bind(fbl->main);
-
+		GPU_framebuffer_bind(fbl->main_fb);
 		DRW_stats_group_end();
 	}
 }