Fix #22645: Texture paint: soften tool does draw brushes

Disable projection painting for soften tools.

Also it looks like smear tools support projection in the code, so
enabled project paint menu for such tools

release/scripts/ui/space_view3d_toolbar.py

@@ -1159,7 +1159,7 @@ class VIEW3D_PT_tools_projectpaint(View3DPanel, bpy.types.Panel):
     @classmethod
     def poll(cls, context):
         brush = context.tool_settings.image_paint.brush
-        return (brush and brush.imagepaint_tool != 'SMEAR')
+        return (brush and brush.imagepaint_tool != 'SOFTEN')
 
     def draw_header(self, context):
         ipaint = context.tool_settings.image_paint

source/blender/editors/sculpt_paint/paint_image.c

@@ -4526,6 +4526,8 @@ typedef struct PaintOperation {
 
 	ViewContext vc;
 	wmTimer *timer;
+
+	short restore_projection;
 } PaintOperation;
 
 static void paint_redraw(bContext *C, ImagePaintState *s, int final)
@@ -4611,6 +4613,13 @@ static int texture_paint_init(bContext *C, wmOperator *op)
 	pop->first= 1;
 	op->customdata= pop;
 	
+	/* XXX: Soften tool does not support projection painting atm, so just disable
+	        projection for this brush */
+	if(brush->imagepaint_tool == PAINT_TOOL_SOFTEN) {
+		settings->imapaint.flag |= IMAGEPAINT_PROJECT_DISABLE;
+		pop->restore_projection = 1;
+	}
+
 	/* initialize from context */
 	if(CTX_wm_region_view3d(C)) {
 		pop->mode= PAINT_MODE_3D;
@@ -4731,6 +4740,9 @@ static void paint_exit(bContext *C, wmOperator *op)
 	if(pop->timer)
 		WM_event_remove_timer(CTX_wm_manager(C), CTX_wm_window(C), pop->timer);
 
+	if(pop->restore_projection)
+		settings->imapaint.flag &= ~IMAGEPAINT_PROJECT_DISABLE;
+
 	settings->imapaint.flag &= ~IMAGEPAINT_DRAWING;
 	imapaint_canvas_free(&pop->s);
 	brush_painter_free(pop->painter);