Shading: Add invert option to Vector Rotate Node

Checkbox to invert rotation angle, suggested by @simonthommes

Differential Revision: https://developer.blender.org/D6932

4 files changed, 19 insertions, 11 deletions

diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index 8633ebca8d6..7ba033432c0 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -748,6 +748,7 @@ static void node_shader_buts_mapping(uiLayout *layout, bContext *UNUSED(C), Poin
 static void node_shader_buts_vector_rotate(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
 {
   uiItemR(layout, ptr, "rotation_type", 0, NULL, ICON_NONE);
+  uiItemR(layout, ptr, "invert", 0, NULL, 0);
 }
 
 static void node_shader_buts_vect_math(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_vector_rotate.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_vector_rotate.glsl
index 405821e01e3..41ad16cce0b 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_vector_rotate.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_vector_rotate.glsl
@@ -20,33 +20,34 @@ vec3 rotate_around_axis(vec3 p, vec3 axis, float angle)
 }
 
 void node_vector_rotate_axis_angle(
-    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, out vec3 vec)
+    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, float invert, out vec3 vec)
 {
   vec = (length(axis) != 0.0) ?
-            rotate_around_axis(vector_in - center, normalize(axis), angle) + center :
+            rotate_around_axis(vector_in - center, normalize(axis), angle * invert) + center :
             vector_in;
 }
 
 void node_vector_rotate_axis_x(
-    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, out vec3 vec)
+    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, float invert, out vec3 vec)
 {
-  vec = rotate_around_axis(vector_in - center, vec3(1.0, 0.0, 0.0), angle) + center;
+  vec = rotate_around_axis(vector_in - center, vec3(1.0, 0.0, 0.0), angle * invert) + center;
 }
 
 void node_vector_rotate_axis_y(
-    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, out vec3 vec)
+    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, float invert, out vec3 vec)
 {
-  vec = rotate_around_axis(vector_in - center, vec3(0.0, 1.0, 0.0), angle) + center;
+  vec = rotate_around_axis(vector_in - center, vec3(0.0, 1.0, 0.0), angle * invert) + center;
 }
 
 void node_vector_rotate_axis_z(
-    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, out vec3 vec)
+    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, float invert, out vec3 vec)
 {
-  vec = rotate_around_axis(vector_in - center, vec3(0.0, 0.0, 1.0), angle) + center;
+  vec = rotate_around_axis(vector_in - center, vec3(0.0, 0.0, 1.0), angle * invert) + center;
 }
 
 void node_vector_rotate_euler_xyz(
-    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, out vec3 vec)
+    vec3 vector_in, vec3 center, vec3 axis, float angle, vec3 rotation, float invert, out vec3 vec)
 {
-  vec = euler_to_mat3(rotation) * (vector_in - center) + center;
+  mat3 rmat = (invert < 0.0) ? transpose(euler_to_mat3(rotation)) : euler_to_mat3(rotation);
+  vec = rmat * (vector_in - center) + center;
 }
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index a0f7f9b585e..e5445546491 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -4166,6 +4166,11 @@ static void def_sh_vector_rotate(StructRNA *srna)
   RNA_def_property_enum_items(prop, rna_enum_vector_rotate_type_items);
   RNA_def_property_ui_text(prop, "Type", "Type of rotation");
   RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_ShaderNode_socket_update");
+
+  prop = RNA_def_property(srna, "invert", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "custom2", 0);
+  RNA_def_property_ui_text(prop, "Invert", "Invert angle");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 }
 
 static void def_sh_attribute(StructRNA *srna)
diff --git a/source/blender/nodes/shader/nodes/node_shader_vector_rotate.c b/source/blender/nodes/shader/nodes/node_shader_vector_rotate.c
index bee5377c438..c94cb903bf3 100644
--- a/source/blender/nodes/shader/nodes/node_shader_vector_rotate.c
+++ b/source/blender/nodes/shader/nodes/node_shader_vector_rotate.c
@@ -51,7 +51,8 @@ static int gpu_shader_vector_rotate(GPUMaterial *mat,
   };
 
   if (node->custom1 < ARRAY_SIZE(names) && names[node->custom1]) {
-    return GPU_stack_link(mat, node, names[node->custom1], in, out);
+    float invert = (node->custom2) ? -1.0 : 1.0;
+    return GPU_stack_link(mat, node, names[node->custom1], in, out, GPU_constant(&invert));
   }
   else {
     return 0;