- template with an example of a modal operator drawing with opengl (draw a line on the screen)

- access to event.mouse_region_x/y
- basic type checking to callback functions (use PyCapsule names)

release/scripts/templates/operator_modal_draw.py

@@ -0,0 +1,69 @@
+import BGL
+
+def draw_callback_px(self, context):
+    print("mouse points", len(self.mouse_path))    
+
+    # 50% alpha, 2 pixel width line
+    BGL.glEnable(BGL.GL_BLEND)
+    BGL.glColor4f(0.0, 0.0, 0.0, 0.5)
+    BGL.glLineWidth(2)
+
+    BGL.glBegin(BGL.GL_LINE_STRIP)
+    for x, y in self.mouse_path:
+        BGL.glVertex2i(x, y)
+
+    BGL.glEnd()
+
+    # restore opengl defaults 
+    BGL.glLineWidth(1)
+    BGL.glDisable(BGL.GL_BLEND)
+    BGL.glColor4f(0.0, 0.0, 0.0, 1.0)
+
+
+class ModalDrawOperator(bpy.types.Operator):
+    '''Draw a line with the mouse'''
+    bl_idname = "object.modal_operator"
+    bl_label = "Simple Modal Operator"
+
+    def modal(self, context, event):
+        context.area.tag_redraw()
+
+        if event.type == 'MOUSEMOVE':
+            self.mouse_path.append((event.mouse_region_x, event.mouse_region_y))
+
+        elif event.type == 'LEFTMOUSE':
+            context.region.callback_remove(self._handle)
+            return {'FINISHED'}
+
+        elif event.type in ('RIGHTMOUSE', 'ESC'):
+            context.region.callback_remove(self._handle)
+            return {'CANCELLED'}
+
+        return {'RUNNING_MODAL'}
+
+    def invoke(self, context, event):
+        if context.area.type == 'VIEW_3D':
+            context.manager.add_modal_handler(self)
+            
+            # Add the region OpenGL drawing callback
+            # draw in view space with 'POST_VIEW' and 'PRE_VIEW'
+            self._handle = context.region.callback_add(draw_callback_px, (self, context), 'POST_PIXEL')
+
+            self.mouse_path = []
+
+            return {'RUNNING_MODAL'}
+        else:
+            self.report({'WARNING'}, "View3D not found, cannot run operator")
+            return {'CANCELLED'}
+
+
+def register():
+    bpy.types.register(ModalDrawOperator)
+
+
+def unregister():
+    bpy.types.unregister(ModalDrawOperator)
+
+
+if __name__ == "__main__":
+    register()

source/blender/blenkernel/intern/unit.c

@@ -170,8 +170,7 @@ static void unit_dual_convert(double value, bUnitCollection *usys,
 {
 	bUnitDef *unit= unit_best_fit(value, usys, NULL, 1);
 
-	if(value < 0.0) *value_a= -floor(-value/unit->scalar) * unit->scalar;
-	else			*value_a=  floor( value/unit->scalar) * unit->scalar;
+	*value_a=  (value < 0.0 ? ceil:floor)(value/unit->scalar) * unit->scalar;
 	*value_b= value - (*value_a);
 
 	*unit_a=	unit;

source/blender/makesrna/intern/rna_wm.c

@@ -1088,6 +1088,16 @@ static void rna_def_event(BlenderRNA *brna)
 	RNA_def_property_int_sdna(prop, NULL, "y");
 	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
 	RNA_def_property_ui_text(prop, "Mouse Y Position", "The window relative horizontal location of the mouse");
+
+	prop= RNA_def_property(srna, "mouse_region_x", PROP_INT, PROP_NONE);
+	RNA_def_property_int_sdna(prop, NULL, "mval[0]");
+	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
+	RNA_def_property_ui_text(prop, "Mouse X Position", "The region relative vertical location of the mouse");
+
+	prop= RNA_def_property(srna, "mouse_region_y", PROP_INT, PROP_NONE);
+	RNA_def_property_int_sdna(prop, NULL, "mval[1]");
+	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
+	RNA_def_property_ui_text(prop, "Mouse Y Position", "The region relative horizontal location of the mouse");
 	
 	prop= RNA_def_property(srna, "mouse_prev_x", PROP_INT, PROP_NONE);
 	RNA_def_property_int_sdna(prop, NULL, "prevx");

source/blender/python/intern/bpy_rna_callback.c

@@ -32,12 +32,9 @@
 #include "BKE_context.h"
 #include "ED_space_api.h"
 
-EnumPropertyItem region_draw_mode_items[] = {
-	{REGION_DRAW_POST_VIEW, "POST_VIEW", 0, "Pose View", ""},
-	{REGION_DRAW_POST_PIXEL, "POST_PIXEL", 0, "Post Pixel", ""},
-	{REGION_DRAW_PRE_VIEW, "PRE_VIEW", 0, "Pre View", ""},
-	{0, NULL, 0, NULL, NULL}};
-
+/* use this to stop other capsules from being mis-used */
+#define RNA_CAPSULE_ID "RNA_HANDLE"
+#define RNA_CAPSULE_ID_INVALID "RNA_HANDLE_REMOVED"
 
 void cb_region_draw(const bContext *C, ARegion *ar, void *customdata)
 {
@@ -74,6 +71,12 @@ PyObject *pyrna_callback_add(BPy_StructRNA *self, PyObject *args)
 
 	if(RNA_struct_is_a(self->ptr.type, &RNA_Region)) {
 
+		EnumPropertyItem region_draw_mode_items[] = {
+			{REGION_DRAW_POST_VIEW, "POST_VIEW", 0, "Pose View", ""},
+			{REGION_DRAW_POST_PIXEL, "POST_PIXEL", 0, "Post Pixel", ""},
+			{REGION_DRAW_PRE_VIEW, "PRE_VIEW", 0, "Pre View", ""},
+			{0, NULL, 0, NULL, NULL}};
+
 		if(pyrna_enum_value_from_id(region_draw_mode_items, cb_event_str, &cb_event, "bpy_struct.callback_add()") < 0)
 			return NULL;
 
@@ -81,24 +84,28 @@ PyObject *pyrna_callback_add(BPy_StructRNA *self, PyObject *args)
 		Py_INCREF(args);
 	}
 	else {
-		PyErr_SetString(PyExc_TypeError, "callbcak_add(): type does not suppport cllbacks");
+		PyErr_SetString(PyExc_TypeError, "callback_add(): type does not suppport callbacks");
 		return NULL;
 	}
 
-	return PyCapsule_New((void *)handle, NULL, NULL);
+	return PyCapsule_New((void *)handle, RNA_CAPSULE_ID, NULL);
 }
 
 PyObject *pyrna_callback_remove(BPy_StructRNA *self, PyObject *args)
 {
 	PyObject *py_handle;
-	PyObject *py_args;
 	void *handle;
 	void *customdata;
 
 	if (!PyArg_ParseTuple(args, "O!:callback_remove", &PyCapsule_Type, &py_handle))
 		return NULL;
 
-	handle= PyCapsule_GetPointer(py_handle, NULL);
+	handle= PyCapsule_GetPointer(py_handle, RNA_CAPSULE_ID);
+
+	if(handle==NULL) {
+		PyErr_SetString(PyExc_ValueError, "callback_remove(handle): NULL handle given, invalid or already removed.");
+		return NULL;
+	}
 
 	if(RNA_struct_is_a(self->ptr.type, &RNA_Region)) {
 		customdata= ED_region_draw_cb_customdata(handle);
@@ -107,5 +114,8 @@ PyObject *pyrna_callback_remove(BPy_StructRNA *self, PyObject *args)
 		ED_region_draw_cb_exit(((ARegion *)self->ptr.data)->type, handle);
 	}
 
+	/* dont allow reuse */
+	PyCapsule_SetName(py_handle, RNA_CAPSULE_ID_INVALID);
+
 	Py_RETURN_NONE;
 }