Eevee : TAA : Change post process chain to allow more flexibility

This basically do not use hardware blending and do the blending in the shader.
This will allow neighborhood clamping if we ever implement that.

1 files changed, 79 insertions, 71 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_effects.c b/source/blender/draw/engines/eevee/eevee_effects.c
index 741065a7df3..e4ce35d60f1 100644
--- a/source/blender/draw/engines/eevee/eevee_effects.c
+++ b/source/blender/draw/engines/eevee/eevee_effects.c
@@ -509,6 +509,71 @@ void EEVEE_effects_init(EEVEE_SceneLayerData *sldata, EEVEE_Data *vedata)
 		}
 	}
 
+	if (BKE_collection_engine_property_value_get_bool(props, "taa_enable")) {
+		float persmat[4][4], viewmat[4][4];
+
+		enabled_effects |= EFFECT_TAA | EFFECT_DOUBLE_BUFFER;
+
+		/* Until we support reprojection, we need to make sure
+		 * that the history buffer contains correct information. */
+		bool view_is_valid = stl->g_data->valid_double_buffer;
+
+		view_is_valid = view_is_valid && (stl->g_data->view_updated == false);
+
+		effects->taa_total_sample = BKE_collection_engine_property_value_get_int(props, "taa_samples");
+		MAX2(effects->taa_total_sample, 0);
+
+		DRW_viewport_matrix_get(persmat, DRW_MAT_PERS);
+		DRW_viewport_matrix_get(viewmat, DRW_MAT_VIEW);
+		DRW_viewport_matrix_get(effects->overide_winmat, DRW_MAT_WIN);
+		view_is_valid = view_is_valid && compare_m4m4(persmat, effects->prev_drw_persmat, 0.0001f);
+		copy_m4_m4(effects->prev_drw_persmat, persmat);
+
+		if (view_is_valid &&
+		    ((effects->taa_total_sample == 0) ||
+		     (effects->taa_current_sample < effects->taa_total_sample)))
+		{
+			effects->taa_current_sample += 1;
+
+			effects->taa_alpha = 1.0f / (float)(effects->taa_current_sample);
+
+			double ht_point[2];
+			double ht_offset[2] = {0.0, 0.0};
+			unsigned int ht_primes[2] = {2, 3};
+
+			BLI_halton_2D(ht_primes, ht_offset, effects->taa_current_sample - 1, ht_point);
+
+			window_translate_m4(
+			        effects->overide_winmat, persmat,
+			        ((float)(ht_point[0]) * 2.0f - 1.0f) / viewport_size[0],
+			        ((float)(ht_point[1]) * 2.0f - 1.0f) / viewport_size[1]);
+
+			mul_m4_m4m4(effects->overide_persmat, effects->overide_winmat, viewmat);
+			invert_m4_m4(effects->overide_persinv, effects->overide_persmat);
+			invert_m4_m4(effects->overide_wininv, effects->overide_winmat);
+
+			DRW_viewport_matrix_override_set(effects->overide_persmat, DRW_MAT_PERS);
+			DRW_viewport_matrix_override_set(effects->overide_persinv, DRW_MAT_PERSINV);
+			DRW_viewport_matrix_override_set(effects->overide_winmat, DRW_MAT_WIN);
+			DRW_viewport_matrix_override_set(effects->overide_wininv, DRW_MAT_WININV);
+		}
+		else {
+			effects->taa_current_sample = 1;
+		}
+
+		DRWFboTexture tex_double_buffer = {&txl->depth_double_buffer, DRW_TEX_DEPTH_24};
+
+		DRW_framebuffer_init(&fbl->depth_double_buffer_fb, &draw_engine_eevee_type,
+		                    (int)viewport_size[0], (int)viewport_size[1],
+		                    &tex_double_buffer, 1);
+	}
+	else {
+		/* Cleanup to release memory */
+		DRW_TEXTURE_FREE_SAFE(txl->depth_double_buffer);
+		DRW_FRAMEBUFFER_FREE_SAFE(fbl->depth_double_buffer_fb);
+	}
+
+
 	effects->enabled_effects = enabled_effects;
 
 	/* Only allocate if at least one effect is activated */
@@ -747,70 +812,6 @@ void EEVEE_effects_init(EEVEE_SceneLayerData *sldata, EEVEE_Data *vedata)
 		}
 	}
 
-	if (BKE_collection_engine_property_value_get_bool(props, "taa_enable")) {
-		float persmat[4][4], viewmat[4][4];
-
-		effects->enabled_effects |= EFFECT_TAA | EFFECT_DOUBLE_BUFFER;
-
-		/* Until we support reprojection, we need to make sure
-		 * that the history buffer contains correct information. */
-		bool view_is_valid = stl->g_data->valid_double_buffer;
-
-		view_is_valid = view_is_valid && (stl->g_data->view_updated == false);
-
-		effects->taa_total_sample = BKE_collection_engine_property_value_get_int(props, "taa_samples");
-		MAX2(effects->taa_total_sample, 0);
-
-		DRW_viewport_matrix_get(persmat, DRW_MAT_PERS);
-		DRW_viewport_matrix_get(viewmat, DRW_MAT_VIEW);
-		DRW_viewport_matrix_get(effects->overide_winmat, DRW_MAT_WIN);
-		view_is_valid = view_is_valid && compare_m4m4(persmat, effects->prev_drw_persmat, 0.0001f);
-		copy_m4_m4(effects->prev_drw_persmat, persmat);
-
-		if (view_is_valid &&
-		    ((effects->taa_total_sample == 0) ||
-		     (effects->taa_current_sample < effects->taa_total_sample)))
-		{
-			effects->taa_current_sample += 1;
-
-			effects->taa_alpha = 1.0f - (1.0f / (float)(effects->taa_current_sample));
-
-			double ht_point[2];
-			double ht_offset[2] = {0.0, 0.0};
-			unsigned int ht_primes[2] = {2, 3};
-
-			BLI_halton_2D(ht_primes, ht_offset, effects->taa_current_sample - 1, ht_point);
-
-			window_translate_m4(
-			        effects->overide_winmat, persmat,
-			        ((float)(ht_point[0]) * 2.0f - 1.0f) / viewport_size[0],
-			        ((float)(ht_point[1]) * 2.0f - 1.0f) / viewport_size[1]);
-
-			mul_m4_m4m4(effects->overide_persmat, effects->overide_winmat, viewmat);
-			invert_m4_m4(effects->overide_persinv, effects->overide_persmat);
-			invert_m4_m4(effects->overide_wininv, effects->overide_winmat);
-
-			DRW_viewport_matrix_override_set(effects->overide_persmat, DRW_MAT_PERS);
-			DRW_viewport_matrix_override_set(effects->overide_persinv, DRW_MAT_PERSINV);
-			DRW_viewport_matrix_override_set(effects->overide_winmat, DRW_MAT_WIN);
-			DRW_viewport_matrix_override_set(effects->overide_wininv, DRW_MAT_WININV);
-		}
-		else {
-			effects->taa_current_sample = 1;
-		}
-
-		DRWFboTexture tex_double_buffer = {&txl->depth_double_buffer, DRW_TEX_DEPTH_24};
-
-		DRW_framebuffer_init(&fbl->depth_double_buffer_fb, &draw_engine_eevee_type,
-		                    (int)viewport_size[0], (int)viewport_size[1],
-		                    &tex_double_buffer, 1);
-	}
-	else {
-		/* Cleanup to release memory */
-		DRW_TEXTURE_FREE_SAFE(txl->depth_double_buffer);
-		DRW_FRAMEBUFFER_FREE_SAFE(fbl->depth_double_buffer_fb);
-	}
-
 	/* Normal buffer for deferred passes. */
 	if ((((effects->enabled_effects & EFFECT_GTAO) != 0) && G.debug_value == 6) ||
 	    ((effects->enabled_effects & EFFECT_SSR) != 0))
@@ -874,10 +875,11 @@ void EEVEE_effects_cache_init(EEVEE_SceneLayerData *sldata, EEVEE_Data *vedata)
 	struct Gwn_Batch *quad = DRW_cache_fullscreen_quad_get();
 
 	if ((effects->enabled_effects & EFFECT_TAA) != 0) {
-		psl->taa_resolve = DRW_pass_create("Temporal AA Resolve", DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND);
+		psl->taa_resolve = DRW_pass_create("Temporal AA Resolve", DRW_STATE_WRITE_COLOR);
 		DRWShadingGroup *grp = DRW_shgroup_create(e_data.taa_resolve_sh, psl->taa_resolve);
 
-		DRW_shgroup_uniform_buffer(grp, "colorBuffer", &effects->source_buffer);
+		DRW_shgroup_uniform_buffer(grp, "historyBuffer", &txl->color_double_buffer);
+		DRW_shgroup_uniform_buffer(grp, "colorBuffer", &txl->color);
 		DRW_shgroup_uniform_float(grp, "alpha", &effects->taa_alpha, 1);
 		DRW_shgroup_call_add(grp, quad, NULL);
 	}
@@ -1432,7 +1434,7 @@ void EEVEE_effects_do_gtao(EEVEE_SceneLayerData *UNUSED(sldata), EEVEE_Data *ved
 } ((void)0)
 
 #define SWAP_BUFFERS() {                           \
-	if (effects->source_buffer == txl->color) {    \
+	if (effects->target_buffer != fbl->main) {     \
 		SWAP_DOUBLE_BUFFERS();                     \
 		effects->source_buffer = txl->color_post;  \
 		effects->target_buffer = fbl->main;        \
@@ -1463,16 +1465,22 @@ void EEVEE_draw_effects(EEVEE_Data *vedata)
 	effects->source_buffer = txl->color; /* latest updated texture */
 	effects->target_buffer = fbl->effect_fb; /* next target to render to */
 
-	/* Motion Blur */
+	/* Temporal Anti-Aliasing */
+	/* MUST COME FIRST. */
 	if ((effects->enabled_effects & EFFECT_TAA) != 0) {
 		if (effects->taa_current_sample != 1) {
-			effects->source_buffer = txl->color_double_buffer;
-			DRW_framebuffer_bind(fbl->main);
+			DRW_framebuffer_bind(fbl->effect_fb);
 			DRW_draw_pass(psl->taa_resolve);
-			effects->source_buffer = txl->color;
 
 			/* Restore the depth from sample 1. */
 			DRW_framebuffer_blit(fbl->depth_double_buffer_fb, fbl->main, true);
+
+			/* Special Swap */
+			SWAP(struct GPUFrameBuffer *, fbl->effect_fb, fbl->double_buffer);
+			SWAP(GPUTexture *, txl->color_post, txl->color_double_buffer);
+			swap_double_buffer = false;
+			effects->source_buffer = txl->color_double_buffer;
+			effects->target_buffer = fbl->main;
 		}
 		else {
 			/* Save the depth buffer for the next frame.