Z sampling for nodes backdrop

As it turned out,  the node space was the only place we have the option to sample the backdrop buffer RGB, but not the zed.
This code is copied from image space.

Now one can use the viewer node and sample the depth while looking at the color buffer (so Map Range Node works even better)
Patch written during BlenderPRO 2012, Brasília ;)
(reviewed by Lukas Toenne)

1 files changed, 19 insertions, 2 deletions

diff --git a/source/blender/editors/space_node/node_view.c b/source/blender/editors/space_node/node_view.c
index ccf5c4b540f..a4ea2e3e630 100644
--- a/source/blender/editors/space_node/node_view.c
+++ b/source/blender/editors/space_node/node_view.c
@@ -330,6 +330,12 @@ typedef struct ImageSampleInfo {
 
 	unsigned char col[4];
 	float colf[4];
+	
+	int z;
+	float zf;
+
+	int *zp;
+	float *zfp;
 
 	int draw;
 	int color_manage;
@@ -343,8 +349,7 @@ static void sample_draw(const bContext *C, ARegion *ar, void *arg_info)
 	if (info->draw) {
 		ED_image_draw_info(scene, ar, info->color_manage, FALSE, info->channels,
 		                   info->x, info->y, info->col, info->colf,
-		                   NULL, NULL /* zbuf - unused for nodes */
-		                   );
+		                   info->zp, info->zfp);
 	}
 }
 
@@ -443,6 +448,9 @@ static void sample_apply(bContext *C, wmOperator *op, wmEvent *event)
 		info->draw = 1;
 		info->channels = ibuf->channels;
 
+		info->zp = NULL;
+		info->zfp = NULL;
+
 		if (ibuf->rect) {
 			cp = (unsigned char *)(ibuf->rect + y * ibuf->x + x);
 
@@ -468,6 +476,15 @@ static void sample_apply(bContext *C, wmOperator *op, wmEvent *event)
 
 			info->color_manage = TRUE;
 		}
+		
+		if (ibuf->zbuf) {
+			info->z = ibuf->zbuf[y * ibuf->x + x];
+			info->zp = &info->z;
+		}
+		if (ibuf->zbuf_float) {
+			info->zf = ibuf->zbuf_float[y * ibuf->x + x];
+			info->zfp = &info->zf;
+		}
 
 		ED_node_sample_set(info->colf);
 	}