[Bf-blender-cvs] [bfe580642f4] master: Fix background image rotation and offset

[Campbell Barton]

Commit: bfe580642f46539ba85341fa8db451c52afd0cb4
Author: Campbell Barton
Date:   Wed Jul 24 22:30:31 2019 +1000
Branches: master
https://developer.blender.org/rBbfe580642f46539ba85341fa8db451c52afd0cb4

Fix background image rotation and offset

- Offset was halved & not compensating for non-square aspect.
- Rotation was flipped.

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

M	source/blender/draw/modes/object_mode.c

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

diff --git a/source/blender/draw/modes/object_mode.c b/source/blender/draw/modes/object_mode.c
index ffa013d2758..8d4083f1723 100644
--- a/source/blender/draw/modes/object_mode.c
+++ b/source/blender/draw/modes/object_mode.c
@@ -1242,7 +1242,7 @@ static void DRW_shgroup_camera_background_images(OBJECT_Shaders *sh_data,
       unit_m4(win_m4_scale);
       unit_m4(win_m4_translate);
       unit_m4(scale_m4);
-      axis_angle_to_mat4_single(rot_m4, 'Z', bgpic->rotation);
+      axis_angle_to_mat4_single(rot_m4, 'Z', -bgpic->rotation);
       unit_m4(translate_m4);
 
       const float *size = DRW_viewport_size_get();
@@ -1311,9 +1311,9 @@ static void DRW_shgroup_camera_background_images(OBJECT_Shaders *sh_data,
       scale_m4[0][0] = scale_x;
       scale_m4[1][1] = scale_y;
 
-      // translate
-      translate_m4[3][0] = bgpic->offset[0];
-      translate_m4[3][1] = bgpic->offset[1];
+      /* Translate, using coordinates that aren't squashed by the aspect. */
+      translate_m4[3][0] = bgpic->offset[0] * 2.0f * max_ff(1.0f, 1.0f / camera_aspect);
+      translate_m4[3][1] = bgpic->offset[1] * 2.0f * max_ff(1.0f, camera_aspect);
 
       mul_m4_series(bg_data->transform_mat,
                     win_m4_translate,