Implement resolution divider in the Blender Internal

Currently resolution divider is not exposed to the
interface yet, and i'm not even sure it needs to be
exposed because it's somewhat weird configuration.
Need to check how often artists are changing start
resolution in Cycles.

Pretty much straightforward implementation with the
only weak part: render result is getting re-allocated
and upscaled when current resolution is finished.
Not sure how to make it faster actually. Maybe it's
just a matter of making upscale fast enough.

Needed to fix some possible memory leak happening
in Freestyle when canceling rendering on a special
stage -- it was missing temp bmain free,

Reviewers: campbellbarton, dingto

CC: sebastian_k, fsiddi, venomgfx

Differential Revision: https://developer.blender.org/D609

2 files changed, 98 insertions, 29 deletions

diff --git a/source/blender/render/extern/include/RE_pipeline.h b/source/blender/render/extern/include/RE_pipeline.h
index 031d6b5a51a..68ac0cd3073 100644
--- a/source/blender/render/extern/include/RE_pipeline.h
+++ b/source/blender/render/extern/include/RE_pipeline.h
@@ -190,7 +190,10 @@ struct RenderLayer *RE_GetRenderLayer(struct RenderResult *rr, const char *name)
 float *RE_RenderLayerGetPass(struct RenderLayer *rl, int passtype);
 
 /* obligatory initialize call, disprect is optional */
-void RE_InitState(struct Render *re, struct Render *source, struct RenderData *rd, struct SceneRenderLayer *srl, int winx, int winy, rcti *disprect);
+void RE_InitState(struct Render *re, struct Render *source, struct RenderData *rd,
+                  struct SceneRenderLayer *srl,
+                  int winx, int winy, rcti *disprect);
+void RE_ChangeResolution(struct Render *re, int winx, int winy, rcti *disprect);
 
 /* set up the viewplane/perspective matrix, three choices */
 struct Object *RE_GetCamera(struct Render *re); /* return camera override if set */
diff --git a/source/blender/render/intern/source/pipeline.c b/source/blender/render/intern/source/pipeline.c
index 537714ace0b..d4f089d7c3b 100644
--- a/source/blender/render/intern/source/pipeline.c
+++ b/source/blender/render/intern/source/pipeline.c
@@ -511,32 +511,9 @@ static int check_mode_full_sample(RenderData *rd)
 	return scemode;
 }
 
-/* what doesn't change during entire render sequence */
-/* disprect is optional, if NULL it assumes full window render */
-void RE_InitState(Render *re, Render *source, RenderData *rd, SceneRenderLayer *srl, int winx, int winy, rcti *disprect)
+static void re_init_resolution(Render *re, Render *source,
+                               int winx, int winy, rcti *disprect)
 {
-	bool had_freestyle = (re->r.mode & R_EDGE_FRS) != 0;
-
-	re->ok = true;   /* maybe flag */
-	
-	re->i.starttime = PIL_check_seconds_timer();
-
-	/* copy render data and render layers for thread safety */
-	BLI_freelistN(&re->r.layers);
-	re->r = *rd;
-	BLI_duplicatelist(&re->r.layers, &rd->layers);
-
-	if (source) {
-		/* reuse border flags from source renderer */
-		re->r.mode &= ~(R_BORDER | R_CROP);
-		re->r.mode |= source->r.mode & (R_BORDER | R_CROP);
-
-		/* dimensions shall be shared between all renderers */
-		re->r.xsch = source->r.xsch;
-		re->r.ysch = source->r.ysch;
-		re->r.size = source->r.size;
-	}
-
 	re->winx = winx;
 	re->winy = winy;
 	if (source && (source->r.mode & R_BORDER)) {
@@ -570,7 +547,41 @@ void RE_InitState(Render *re, Render *source, RenderData *rd, SceneRenderLayer *
 		re->rectx = winx;
 		re->recty = winy;
 	}
+
+	/* we clip faces with a minimum of 2 pixel boundary outside of image border. see zbuf.c */
+	re->clipcrop = 1.0f + 2.0f / (float)(re->winx > re->winy ? re->winy : re->winx);
+}
+
+/* what doesn't change during entire render sequence */
+/* disprect is optional, if NULL it assumes full window render */
+void RE_InitState(Render *re, Render *source, RenderData *rd,
+                  SceneRenderLayer *srl,
+                  int winx, int winy, rcti *disprect)
+{
+	bool had_freestyle = (re->r.mode & R_EDGE_FRS) != 0;
+
+	re->ok = true;   /* maybe flag */
 	
+	re->i.starttime = PIL_check_seconds_timer();
+
+	/* copy render data and render layers for thread safety */
+	BLI_freelistN(&re->r.layers);
+	re->r = *rd;
+	BLI_duplicatelist(&re->r.layers, &rd->layers);
+
+	if (source) {
+		/* reuse border flags from source renderer */
+		re->r.mode &= ~(R_BORDER | R_CROP);
+		re->r.mode |= source->r.mode & (R_BORDER | R_CROP);
+
+		/* dimensions shall be shared between all renderers */
+		re->r.xsch = source->r.xsch;
+		re->r.ysch = source->r.ysch;
+		re->r.size = source->r.size;
+	}
+
+	re_init_resolution(re, source, winx, winy, disprect);
+
 	if (re->rectx < 1 || re->recty < 1 || (BKE_imtype_is_movie(rd->im_format.imtype) &&
 	                                       (re->rectx < 16 || re->recty < 16) ))
 	{
@@ -654,14 +665,69 @@ void RE_InitState(Render *re, Render *source, RenderData *rd, SceneRenderLayer *
 
 	BLI_rw_mutex_unlock(&re->resultmutex);
 	
-	/* we clip faces with a minimum of 2 pixel boundary outside of image border. see zbuf.c */
-	re->clipcrop = 1.0f + 2.0f / (float)(re->winx > re->winy ? re->winy : re->winx);
-	
 	re->mblur_offs = re->field_offs = 0.f;
 	
 	RE_init_threadcount(re);
 }
 
+static void render_result_rescale(Render *re)
+{
+	RenderResult *result = re->result;
+	int x, y;
+	float scale_x, scale_y;
+	float *src_rectf;
+
+	src_rectf = result->rectf;
+	if (src_rectf == NULL) {
+		RenderLayer *rl = render_get_active_layer(re, re->result);
+		if (rl != NULL) {
+			src_rectf = rl->rectf;
+		}
+	}
+
+	if (src_rectf != NULL) {
+		float *dst_rectf = NULL;
+		re->result = render_result_new(re,
+		                               &re->disprect,
+		                               0,
+		                               RR_USE_MEM,
+		                               RR_ALL_LAYERS);
+
+		dst_rectf = re->result->rectf;
+		if (dst_rectf == NULL) {
+			RenderLayer *rl;
+			rl = render_get_active_layer(re, re->result);
+			if (rl != NULL) {
+				dst_rectf = rl->rectf;
+			}
+		}
+
+		scale_x = (float) result->rectx / re->result->rectx;
+		scale_y = (float) result->recty / re->result->recty;
+		for (x = 0; x < re->result->rectx; ++x) {
+			for (y = 0; y < re->result->recty; ++y) {
+				int src_x = x * scale_x,
+				    src_y = y * scale_y;
+				int dst_index = y * re->result->rectx + x,
+				    src_index = src_y * result->rectx + src_x;
+				copy_v4_v4(dst_rectf + dst_index * 4,
+				           src_rectf + src_index * 4);
+			}
+		}
+	}
+
+	render_result_free(result);
+}
+
+void RE_ChangeResolution(Render *re, int winx, int winy, rcti *disprect)
+{
+	re_init_resolution(re, NULL, winx, winy, disprect);
+
+	BLI_rw_mutex_lock(&re->resultmutex, THREAD_LOCK_WRITE);
+	render_result_rescale(re);
+	BLI_rw_mutex_unlock(&re->resultmutex);
+}
+
 /* update some variables that can be animated, and otherwise wouldn't be due to
  * RenderData getting copied once at the start of animation render */
 static void render_update_anim_renderdata(Render *re, RenderData *rd)