Draw manager: Make evaluation context a part of context state

This way we don't have to re-initialize the full evaluation
context in every area we need it.

source/blender/draw/engines/eevee/eevee_motion_blur.c

@@ -59,7 +59,6 @@ static void eevee_motion_blur_camera_get_matrix_at_time(
         float time,
         float r_mat[4][4])
 {
-	EvaluationContext eval_ctx;
 	float obmat[4][4];
 
 	/* HACK */
@@ -68,19 +67,9 @@ static void eevee_motion_blur_camera_get_matrix_at_time(
 	memcpy(&camdata_cpy, camera->data, sizeof(camdata_cpy));
 	cam_cpy.data = &camdata_cpy;
 
-	/* NOTE: Mode corresponds to old usage of eval_ctx from viewport (which was
-	 * actually coming from bmain). It was always DAG_EVAL_VIEWPORT. For F12
-	 * render this should be DAG_EVAL_RENDER, but the whole hack is to be
-	 * reconsidered first anyway.
-	 */
 	const DRWContextState *draw_ctx = DRW_context_state_get();
-	DEG_evaluation_context_init_from_scene(
-	        &eval_ctx,
-	        scene,
-	        draw_ctx->view_layer,
-	        draw_ctx->engine_type,
-	        draw_ctx->object_mode,
-	        DAG_EVAL_VIEWPORT);
+	/* We will be modifying time, so we create copy of eval_ctx. */
+	EvaluationContext eval_ctx = draw_ctx->eval_ctx;
 	eval_ctx.ctime = time;
 
 	/* Past matrix */

source/blender/draw/intern/DRW_render.h

@@ -57,6 +57,8 @@
 
 #include "RE_engine.h"
 
+#include "DEG_depsgraph.h"
+
 struct rcti;
 struct bContext;
 struct GPUFrameBuffer;
@@ -504,6 +506,7 @@ typedef struct DRWContextState {
 
 	struct RenderEngineType *engine_type;
 
+	EvaluationContext eval_ctx;
 	struct Depsgraph *depsgraph;
 
 	eObjectMode object_mode;

source/blender/draw/intern/draw_manager.c

@@ -346,6 +346,17 @@ static void drw_viewport_cache_resize(void)
 	DRW_instance_data_list_resize(DST.idatalist);
 }
 
+static void drw_state_eval_ctx_init(DRWManager *dst)
+{
+	DRWContextState *draw_ctx = &dst->draw_ctx;
+	DEG_evaluation_context_init_from_scene(
+	        &draw_ctx->eval_ctx,
+	        draw_ctx->scene,
+	        draw_ctx->view_layer,
+	        draw_ctx->engine_type,
+	        draw_ctx->object_mode,
+	        DST.options.is_scene_render ? DAG_EVAL_RENDER : DAG_EVAL_VIEWPORT);
+}
 
 /* Not a viewport variable, we could split this out. */
 static void drw_context_state_init(void)
@@ -368,6 +379,8 @@ static void drw_context_state_init(void)
 	else {
 		DST.draw_ctx.object_pose = NULL;
 	}
+
+	drw_state_eval_ctx_init(&DST);
 }
 
 /* It also stores viewport variable to an immutable place: DST

source/blender/draw/modes/sculpt_mode.c

@@ -193,12 +193,8 @@ static void SCULPT_cache_populate(void *vedata, Object *ob)
 
 	if (ob->type == OB_MESH) {
 		const DRWContextState *draw_ctx = DRW_context_state_get();
-		EvaluationContext eval_ctx;
-
-		CTX_data_eval_ctx(draw_ctx->evil_C, &eval_ctx);
 
 		if (ob->sculpt && (ob == draw_ctx->obact)) {
-
 			/* XXX, needed for dyntopo-undo (which clears).
 			 * probably depsgraph should handlle? in 2.7x getting derived-mesh does this (mesh_build_data) */
 			if (ob->sculpt->pbvh == NULL) {
@@ -206,7 +202,7 @@ static void SCULPT_cache_populate(void *vedata, Object *ob)
 				 * but this avoids waiting on first stroke) */
 				Scene *scene = draw_ctx->scene;
 
-				BKE_sculpt_update_mesh_elements(&eval_ctx, scene, scene->toolsettings->sculpt, ob, false, false);
+				BKE_sculpt_update_mesh_elements(&draw_ctx->eval_ctx, scene, scene->toolsettings->sculpt, ob, false, false);
 			}
 
 			PBVH *pbvh = ob->sculpt->pbvh;