[Bf-blender-cvs] [90758ed] blender-v2.77-release: Fix T47827: Single Channel Preview Error

[Campbell Barton]

Commit: 90758ed2e85a18e6c5eea276ceacf61410e3d84d
Author: Campbell Barton
Date:   Thu Mar 17 23:52:49 2016 +1100
Branches: blender-v2.77-release
https://developer.blender.org/rB90758ed2e85a18e6c5eea276ceacf61410e3d84d

Fix T47827: Single Channel Preview Error

Fix by @sergey with own fix for big endian.

===================================================================

M	source/blender/editors/space_image/image_draw.c
M	source/blender/editors/space_node/drawnode.c

===================================================================

diff --git a/source/blender/editors/space_image/image_draw.c b/source/blender/editors/space_image/image_draw.c
index 669fbd2..0ddbb11 100644
--- a/source/blender/editors/space_image/image_draw.c
+++ b/source/blender/editors/space_image/image_draw.c
@@ -480,9 +480,9 @@ static void sima_draw_zbuffloat_pixels(Scene *scene, float x1, float y1, int rec
 static int draw_image_channel_offset(SpaceImage *sima)
 {
 #ifdef __BIG_ENDIAN__
-	if      (sima->flag & SI_SHOW_R) return 2;
+	if      (sima->flag & SI_SHOW_R) return 0;
 	else if (sima->flag & SI_SHOW_G) return 1;
-	else                             return 0;
+	else                             return 2;
 #else
 	if      (sima->flag & SI_SHOW_R) return 1;
 	else if (sima->flag & SI_SHOW_G) return 2;
@@ -540,7 +540,7 @@ static void draw_image_buffer(const bContext *C, SpaceImage *sima, ARegion *ar,
 			if (display_buffer != NULL) {
 				int channel_offset = draw_image_channel_offset(sima);
 				glaDrawPixelsSafe(x, y, ibuf->x, ibuf->y, ibuf->x, GL_LUMINANCE, GL_UNSIGNED_INT,
-				                  display_buffer + channel_offset);
+				                  display_buffer - (4 - channel_offset));
 			}
 			if (cache_handle != NULL) {
 				IMB_display_buffer_release(cache_handle);
@@ -621,7 +621,7 @@ static void draw_image_buffer_tiled(SpaceImage *sima, ARegion *ar, Scene *scene,
 			}
 			else {
 				glaDrawPixelsSafe(x, y, dx, dy, dx, GL_LUMINANCE, GL_UNSIGNED_INT,
-				                  (unsigned char *)rect + channel_offset);
+				                  (unsigned char *)rect - (4 - channel_offset));
 			}
 		}
 	}
diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index ed207e2..61341fb 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -3236,9 +3236,9 @@ void draw_nodespace_back_pix(const bContext *C, ARegion *ar, SpaceNode *snode, b
 				display_buffer = IMB_display_buffer_acquire_ctx(C, ibuf, &cache_handle);
 				
 #ifdef __BIG_ENDIAN__
-				if      (snode->flag & SNODE_SHOW_R) ofs = 2;
+				if      (snode->flag & SNODE_SHOW_R) ofs = 0;
 				else if (snode->flag & SNODE_SHOW_G) ofs = 1;
-				else                                 ofs = 0;
+				else                                 ofs = 2;
 #else
 				if      (snode->flag & SNODE_SHOW_R) ofs = 1;
 				else if (snode->flag & SNODE_SHOW_G) ofs = 2;
@@ -3249,7 +3249,7 @@ void draw_nodespace_back_pix(const bContext *C, ARegion *ar, SpaceNode *snode, b
 				/* swap bytes, so alpha is most significant one, then just draw it as luminance int */
 				
 				glaDrawPixelsSafe(x, y, ibuf->x, ibuf->y, ibuf->x, GL_LUMINANCE, GL_UNSIGNED_INT,
-				                  display_buffer + ofs);
+				                  display_buffer - (4 - ofs));
 				
 				glPixelZoom(1.0f, 1.0f);
 			}