Fix pathological corner case in drawing tileset editor

Interleaving draw_rect calls with and without a texture forces every rect to
have its own draw call. In this case it meant that there is a draw call for every single
tile in the atlas. This change makes it so the renderer can batch draw calls
which reduced the draw call count by a factor of 512

2 files changed, 40 insertions, 16 deletions

diff --git a/drivers/gles3/rasterizer_canvas_gles3.cpp b/drivers/gles3/rasterizer_canvas_gles3.cpp
index 29252c8677..b05817cd8e 100644
--- a/drivers/gles3/rasterizer_canvas_gles3.cpp
+++ b/drivers/gles3/rasterizer_canvas_gles3.cpp
@@ -581,7 +581,7 @@ void RasterizerCanvasGLES3::_render_items(RID p_to_render_target, int p_item_cou
 		_record_item_commands(ci, p_canvas_transform_inverse, current_clip, blend_mode, p_lights, index, batch_broken);
 	}
 
-	if (r_last_index >= index) {
+	if (index == 0) {
 		// Nothing to render, just return.
 		state.current_batch_index = 0;
 		state.canvas_instance_batches.clear();
@@ -1325,7 +1325,7 @@ void RasterizerCanvasGLES3::_render_batch(Light *p_lights, uint32_t p_index) {
 
 void RasterizerCanvasGLES3::_add_to_batch(uint32_t &r_index, bool &r_batch_broken) {
 	if (r_index >= data.max_instances_per_ubo - 1) {
-		WARN_PRINT_ONCE("Trying to draw too many items. Please increase maximum number of items in the project settings 'rendering/gl_compatibility/item_buffer_size'");
+		ERR_PRINT_ONCE("Trying to draw too many items. Please increase maximum number of items in the project settings 'rendering/gl_compatibility/item_buffer_size'");
 		return;
 	}
 
diff --git a/editor/plugins/tiles/tile_atlas_view.cpp b/editor/plugins/tiles/tile_atlas_view.cpp
index 69104cadec..4fe7178e7e 100644
--- a/editor/plugins/tiles/tile_atlas_view.cpp
+++ b/editor/plugins/tiles/tile_atlas_view.cpp
@@ -192,6 +192,19 @@ void TileAtlasView::_draw_base_tiles() {
 					rect = rect.intersection(Rect2i(Vector2(), texture->get_size()));
 					if (rect.size.x > 0 && rect.size.y > 0) {
 						base_tiles_draw->draw_texture_rect_region(texture, rect, rect);
+					}
+				}
+			}
+		}
+
+		// Draw dark overlay after for performance reasons.
+		for (int x = 0; x < grid_size.x; x++) {
+			for (int y = 0; y < grid_size.y; y++) {
+				Vector2i coords = Vector2i(x, y);
+				if (tile_set_atlas_source->get_tile_at_coords(coords) == TileSetSource::INVALID_ATLAS_COORDS) {
+					Rect2i rect = Rect2i((texture_region_size + separation) * coords + margins, texture_region_size + separation);
+					rect = rect.intersection(Rect2i(Vector2(), texture->get_size()));
+					if (rect.size.x > 0 && rect.size.y > 0) {
 						base_tiles_draw->draw_rect(rect, Color(0.0, 0.0, 0.0, 0.5));
 					}
 				}
@@ -242,23 +255,34 @@ void TileAtlasView::_draw_base_tiles() {
 
 				// Draw the tile.
 				TileMap::draw_tile(base_tiles_draw->get_canvas_item(), offset_pos, tile_set, source_id, atlas_coords, 0, frame);
+			}
+		}
 
-				// Draw, the texture in the separation areas
-				if (separation.x > 0) {
-					Rect2i right_sep_rect = Rect2i(base_frame_rect.get_position() + Vector2i(base_frame_rect.size.x, 0), Vector2i(separation.x, base_frame_rect.size.y));
-					right_sep_rect = right_sep_rect.intersection(Rect2i(Vector2(), texture->get_size()));
-					if (right_sep_rect.size.x > 0 && right_sep_rect.size.y > 0) {
-						base_tiles_draw->draw_texture_rect_region(texture, right_sep_rect, right_sep_rect);
-						base_tiles_draw->draw_rect(right_sep_rect, Color(0.0, 0.0, 0.0, 0.5));
+		// Draw Dark overlay on separation in its own pass.
+		if (separation.x > 0 || separation.y > 0) {
+			for (int i = 0; i < tile_set_atlas_source->get_tiles_count(); i++) {
+				Vector2i atlas_coords = tile_set_atlas_source->get_tile_id(i);
+
+				for (int frame = 0; frame < tile_set_atlas_source->get_tile_animation_frames_count(atlas_coords); frame++) {
+					// Update the y to max value.
+					Rect2i base_frame_rect = tile_set_atlas_source->get_tile_texture_region(atlas_coords, frame);
+
+					if (separation.x > 0) {
+						Rect2i right_sep_rect = Rect2i(base_frame_rect.get_position() + Vector2i(base_frame_rect.size.x, 0), Vector2i(separation.x, base_frame_rect.size.y));
+						right_sep_rect = right_sep_rect.intersection(Rect2i(Vector2(), texture->get_size()));
+						if (right_sep_rect.size.x > 0 && right_sep_rect.size.y > 0) {
+							//base_tiles_draw->draw_texture_rect_region(texture, right_sep_rect, right_sep_rect);
+							base_tiles_draw->draw_rect(right_sep_rect, Color(0.0, 0.0, 0.0, 0.5));
+						}
 					}
-				}
 
-				if (separation.y > 0) {
-					Rect2i bottom_sep_rect = Rect2i(base_frame_rect.get_position() + Vector2i(0, base_frame_rect.size.y), Vector2i(base_frame_rect.size.x + separation.x, separation.y));
-					bottom_sep_rect = bottom_sep_rect.intersection(Rect2i(Vector2(), texture->get_size()));
-					if (bottom_sep_rect.size.x > 0 && bottom_sep_rect.size.y > 0) {
-						base_tiles_draw->draw_texture_rect_region(texture, bottom_sep_rect, bottom_sep_rect);
-						base_tiles_draw->draw_rect(bottom_sep_rect, Color(0.0, 0.0, 0.0, 0.5));
+					if (separation.y > 0) {
+						Rect2i bottom_sep_rect = Rect2i(base_frame_rect.get_position() + Vector2i(0, base_frame_rect.size.y), Vector2i(base_frame_rect.size.x + separation.x, separation.y));
+						bottom_sep_rect = bottom_sep_rect.intersection(Rect2i(Vector2(), texture->get_size()));
+						if (bottom_sep_rect.size.x > 0 && bottom_sep_rect.size.y > 0) {
+							//base_tiles_draw->draw_texture_rect_region(texture, bottom_sep_rect, bottom_sep_rect);
+							base_tiles_draw->draw_rect(bottom_sep_rect, Color(0.0, 0.0, 0.0, 0.5));
+						}
 					}
 				}
 			}