Eevee: Implement Overscan option

This option make the internal render size larger than the output size in
order to minimize screenspace effects disapearing at the render edges.

The overscan size added around the render is the maximum dimension
multiplied by the overscan percentage.

1 files changed, 44 insertions, 15 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_render.c b/source/blender/draw/engines/eevee/eevee_render.c
index 86c20ee54da..a2c44cbcd38 100644
--- a/source/blender/draw/engines/eevee/eevee_render.c
+++ b/source/blender/draw/engines/eevee/eevee_render.c
@@ -33,6 +33,8 @@
 #include "DNA_node_types.h"
 #include "DNA_object_types.h"
 
+#include "BKE_camera.h"
+
 #include "BLI_rand.h"
 #include "BLI_rect.h"
 
@@ -54,6 +56,7 @@ void EEVEE_render_init(EEVEE_Data *ved, RenderEngine *engine, struct Depsgraph *
 	EEVEE_FramebufferList *fbl = vedata->fbl;
 	EEVEE_ViewLayerData *sldata = EEVEE_view_layer_data_ensure();
 	Scene *scene = DEG_get_evaluated_scene(depsgraph);
+	const float *size_orig = DRW_viewport_size_get();
 
 	/* Init default FB and render targets:
 	 * In render mode the default framebuffer is not generated
@@ -62,6 +65,28 @@ void EEVEE_render_init(EEVEE_Data *ved, RenderEngine *engine, struct Depsgraph *
 	DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
 	DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
 
+	/* Alloc transient data. */
+	if (!stl->g_data) {
+		stl->g_data = MEM_callocN(sizeof(*stl->g_data), __func__);
+	}
+	EEVEE_PrivateData *g_data = stl->g_data;
+	g_data->background_alpha = DRW_state_draw_background() ? 1.0f : 0.0f;
+	g_data->valid_double_buffer = 0;
+	copy_v2_v2(g_data->size_orig, size_orig);
+
+	if (scene->eevee.flag & SCE_EEVEE_OVERSCAN) {
+		g_data->overscan = scene->eevee.overscan / 100.0f;
+		g_data->overscan_pixels = roundf(max_ff(size_orig[0], size_orig[1]) * g_data->overscan);
+	}
+	else {
+		g_data->overscan = 0.0f;
+		g_data->overscan_pixels = 0.0f;
+	}
+
+	/* XXX overiding viewport size. Simplify things but is not really 100% safe. */
+	DRW_render_viewport_size_set((int[2]){size_orig[0] + g_data->overscan_pixels * 2.0f,
+	                                      size_orig[1] + g_data->overscan_pixels * 2.0f});
+
 	/* TODO 32 bit depth */
 	DRW_texture_ensure_fullscreen_2D(&dtxl->depth, GPU_DEPTH24_STENCIL8, 0);
 	DRW_texture_ensure_fullscreen_2D(&txl->color, GPU_RGBA32F, DRW_TEX_FILTER | DRW_TEX_MIPMAP);
@@ -79,14 +104,6 @@ void EEVEE_render_init(EEVEE_Data *ved, RenderEngine *engine, struct Depsgraph *
 		GPU_ATTACHMENT_TEXTURE(txl->color)
 	});
 
-	/* Alloc transient data. */
-	if (!stl->g_data) {
-		stl->g_data = MEM_callocN(sizeof(*stl->g_data), __func__);
-	}
-	EEVEE_PrivateData *g_data = stl->g_data;
-	g_data->background_alpha = DRW_state_draw_background() ? 1.0f : 0.0f;
-	g_data->valid_double_buffer = 0;
-
 	/* Alloc common ubo data. */
 	if (sldata->common_ubo == NULL) {
 		sldata->common_ubo = DRW_uniformbuffer_create(sizeof(sldata->common_data), &sldata->common_data);
@@ -102,6 +119,8 @@ void EEVEE_render_init(EEVEE_Data *ved, RenderEngine *engine, struct Depsgraph *
 	RE_GetCameraWindow(engine->re, ob_camera_eval, frame, g_data->winmat);
 	RE_GetCameraModelMatrix(engine->re, ob_camera_eval, g_data->viewinv);
 
+	RE_GetCameraWindowWithOverscan(engine->re, g_data->winmat, g_data->overscan);
+
 	invert_m4_m4(g_data->viewmat, g_data->viewinv);
 	mul_m4_m4m4(g_data->persmat, g_data->winmat, g_data->viewmat);
 	invert_m4_m4(g_data->persinv, g_data->persmat);
@@ -189,7 +208,8 @@ static void eevee_render_result_combined(
 
 	GPU_framebuffer_bind(vedata->stl->effects->final_fb);
 	GPU_framebuffer_read_color(vedata->stl->effects->final_fb,
-	                           rect->xmin, rect->ymin,
+	                           vedata->stl->g_data->overscan_pixels + rect->xmin,
+	                           vedata->stl->g_data->overscan_pixels + rect->ymin,
 	                           BLI_rcti_size_x(rect), BLI_rcti_size_y(rect),
 	                           4, 0, rp->rect);
 
@@ -217,7 +237,8 @@ static void eevee_render_result_subsurface(
 
 		GPU_framebuffer_bind(vedata->fbl->sss_accum_fb);
 		GPU_framebuffer_read_color(vedata->fbl->sss_accum_fb,
-		                           rect->xmin, rect->ymin,
+		                           vedata->stl->g_data->overscan_pixels + rect->xmin,
+		                           vedata->stl->g_data->overscan_pixels + rect->ymin,
 		                           BLI_rcti_size_x(rect), BLI_rcti_size_y(rect),
 		                           3, 1, rp->rect);
 
@@ -232,7 +253,8 @@ static void eevee_render_result_subsurface(
 
 		GPU_framebuffer_bind(vedata->fbl->sss_accum_fb);
 		GPU_framebuffer_read_color(vedata->fbl->sss_accum_fb,
-		                           rect->xmin, rect->ymin,
+		                           vedata->stl->g_data->overscan_pixels + rect->xmin,
+		                           vedata->stl->g_data->overscan_pixels + rect->ymin,
 		                           BLI_rcti_size_x(rect), BLI_rcti_size_y(rect),
 		                           3, 0, rp->rect);
 
@@ -266,7 +288,8 @@ static void eevee_render_result_normal(
 
 		GPU_framebuffer_bind(vedata->fbl->main_fb);
 		GPU_framebuffer_read_color(vedata->fbl->main_fb,
-		                           rect->xmin, rect->ymin,
+		                           g_data->overscan_pixels + rect->xmin,
+		                           g_data->overscan_pixels + rect->ymin,
 		                           BLI_rcti_size_x(rect), BLI_rcti_size_y(rect),
 		                           3, 1, rp->rect);
 
@@ -312,7 +335,8 @@ static void eevee_render_result_z(
 
 		GPU_framebuffer_bind(vedata->fbl->main_fb);
 		GPU_framebuffer_read_depth(vedata->fbl->main_fb,
-		                           rect->xmin, rect->ymin,
+		                           g_data->overscan_pixels + rect->xmin,
+		                           g_data->overscan_pixels + rect->ymin,
 		                           BLI_rcti_size_x(rect), BLI_rcti_size_y(rect),
 		                           rp->rect);
 
@@ -348,7 +372,8 @@ static void eevee_render_result_mist(
 
 		GPU_framebuffer_bind(vedata->fbl->mist_accum_fb);
 		GPU_framebuffer_read_color(vedata->fbl->mist_accum_fb,
-		                           rect->xmin, rect->ymin,
+		                           vedata->stl->g_data->overscan_pixels + rect->xmin,
+		                           vedata->stl->g_data->overscan_pixels + rect->ymin,
 		                           BLI_rcti_size_x(rect), BLI_rcti_size_y(rect),
 		                           1, 0, rp->rect);
 
@@ -376,7 +401,8 @@ static void eevee_render_result_occlusion(
 
 		GPU_framebuffer_bind(vedata->fbl->ao_accum_fb);
 		GPU_framebuffer_read_color(vedata->fbl->ao_accum_fb,
-		                           rect->xmin, rect->ymin,
+		                           vedata->stl->g_data->overscan_pixels + rect->xmin,
+		                           vedata->stl->g_data->overscan_pixels + rect->ymin,
 		                           BLI_rcti_size_x(rect), BLI_rcti_size_y(rect),
 		                           3, 0, rp->rect);
 
@@ -561,6 +587,9 @@ void EEVEE_render_draw(EEVEE_Data *vedata, RenderEngine *engine, RenderLayer *rl
 	eevee_render_result_subsurface(rl, viewname, rect, vedata, sldata, render_samples);
 	eevee_render_result_mist(rl, viewname, rect, vedata, sldata, render_samples);
 	eevee_render_result_occlusion(rl, viewname, rect, vedata, sldata, render_samples);
+
+	/* Restore original viewport size. */
+	DRW_render_viewport_size_set((int[2]){g_data->size_orig[0], g_data->size_orig[1]});
 }
 
 void EEVEE_render_update_passes(RenderEngine *engine, Scene *scene, ViewLayer *view_layer)