Merge pull request #597 from MyreMylar/premul-alpha-everywhere

use premul_alpha everywhere

docs/source/theme_reference/theme_button.rst

@@ -93,27 +93,31 @@ Images
     - "**package** - The name of the python package containing this resource - e.g. 'data.images'
     - "**resource** - The file name of the resource in the python package - e.g. 'splat.png' - Use a 'package' and 'resource' or a 'path' not both.
     - "**sub_surface_rect**" - An optional rectangle (described like "x,y,width,height") that will be used to grab a smaller portion of the image specified. This allows us to create many image surfaces from one image file.
+    - "**premultiplied**" - Optional parameter to declare that a loaded image already contains premultiplied alpha and does not need premultiplying. Set to "1" to enable, "0" to disable (default).
 
  - "**hovered_image**" - The image displayed in the buttons hovered state. It has the following block of sub-parameters:
 
     - "**path**" - The string path to the image to be displayed. OR
     - "**package** - The name of the python package containing this resource - e.g. 'data.images'
     - "**resource** - The file name of the resource in the python package - e.g. 'splat.png' - Use a 'package' and 'resource' or a 'path' not both.
     - "**sub_surface_rect**" - An optional rectangle (described like "x,y,width,height") that will be used to grab a smaller portion of the image specified. This allows us to create many image surfaces from one image file.
+    - "**premultiplied**" - Optional parameter to declare that a loaded image already contains premultiplied alpha and does not need premultiplying. Set to "1" to enable, "0" to disable (default).
 
  - "**selected_image**" - The image displayed in the buttons select focused state. It has the following block of sub-parameters:
 
     - "**path**" - The string path to the image to be displayed. OR
     - "**package** - The name of the python package containing this resource - e.g. 'data.images'
     - "**resource** - The file name of the resource in the python package - e.g. 'splat.png' - Use a 'package' and 'resource' or a 'path' not both.
     - "**sub_surface_rect**" - An optional rectangle (described like "x,y,width,height") that will be used to grab a smaller portion of the image specified. This allows us to create many image surfaces from one image file.
+    - "**premultiplied**" - Optional parameter to declare that a loaded image already contains premultiplied alpha and does not need premultiplying. Set to "1" to enable, "0" to disable (default).
 
  - "**disabled_image**" - The image displayed in the buttons disabled state. It has the following block of sub-parameters:
 
     - "**path**" - The string path to the image to be displayed. OR
     - "**package** - The name of the python package containing this resource - e.g. 'data.images'
     - "**resource** - The file name of the resource in the python package - e.g. 'splat.png' - Use a 'package' and 'resource' or a 'path' not both.
     - "**sub_surface_rect**" - An optional rectangle (described like "x,y,width,height") that will be used to grab a smaller portion of the image specified. This allows us to create many image surfaces from one image file.
+    - "**premultiplied**" - Optional parameter to declare that a loaded image already contains premultiplied alpha and does not need premultiplying. Set to "1" to enable, "0" to disable (default).
 
 
 Misc

docs/source/theme_reference/theme_panel.rst

@@ -30,6 +30,7 @@ Images
     - "**package** - The name of the python package containing this resource - e.g. 'data.images'
     - "**resource** - The file name of the resource in the python package - e.g. 'splat.png' - Use a 'package' and 'resource' or a 'path' not both.
     - "**sub_surface_rect**" - An optional rectangle (described like "x,y,width,height") that will be used to grab a smaller portion of the image specified. This allows us to create many image surfaces from one image file.
+    - "**premultiplied**" - Optional parameter to declare that a loaded image already contains premultiplied alpha and does not need premultiplying. Set to "1" to enable, "0" to disable (default).
 
 Misc
 ----

pygame_gui/core/ui_appearance_theme.py

@@ -288,11 +288,14 @@ def _load_images(self):
                         self.ui_element_image_surfaces[element_key][image_id] = surf_resource
 
     def _load_image_from_path(self, res_data):
+        premultiplied = False
+        if 'premultiplied' in res_data:
+            premultiplied = bool(res_data['premultiplied'])
         resource_id = res_data['path']
         if resource_id in self.image_resources:
             image_resource = self.image_resources[resource_id]
         else:
-            image_resource = ImageResource(resource_id, res_data['path'])
+            image_resource = ImageResource(resource_id, res_data['path'], premultiplied)
             if self._resource_loader.started():
                 error = image_resource.load()
                 if error is not None:
@@ -304,12 +307,15 @@ def _load_image_from_path(self, res_data):
         return image_resource
 
     def _load_image_resource(self, res_data):
+        premultiplied = False
+        if 'premultiplied' in res_data:
+            premultiplied = bool(res_data['premultiplied'])
         resource_id = (str(res_data['package']) + '/' + str(res_data['resource']))
         if resource_id in self.image_resources:
             image_resource = self.image_resources[resource_id]
         else:
             package_resource = PackageResource(res_data['package'], res_data['resource'])
-            image_resource = ImageResource(resource_id, package_resource)
+            image_resource = ImageResource(resource_id, package_resource, premultiplied)
             if self._resource_loader.started():
                 error = image_resource.load()
                 if error is not None:

pygame_gui/core/utility.py

@@ -279,21 +279,6 @@ def restore_premul_col(premul_colour: pygame.Color) -> pygame.Color:
                         premul_colour.a)
 
 
-def premul_alpha_surface(surface: pygame.surface.Surface) -> pygame.surface.Surface:
-    """
-    Perform a pre-multiply alpha operation on a pygame surface's colours.
-    """
-    surf_copy = surface.copy()
-    surf_copy.fill(pygame.Color('#FFFFFF00'), special_flags=pygame.BLEND_RGB_MAX)
-    manipulate_surf = pygame.surface.Surface(surf_copy.get_size(),
-                                             flags=pygame.SRCALPHA, depth=32)
-    # Can't be exactly transparent black or we trigger SDL1 'bug'
-    manipulate_surf.fill(pygame.Color('#00000001'))
-    manipulate_surf.blit(surf_copy, (0, 0))
-    surface.blit(manipulate_surf, (0, 0), special_flags=pygame.BLEND_RGB_MULT)
-    return surface
-
-
 def render_white_text_alpha_black_bg(font: IGUIFontInterface,
                                      text: str) -> pygame.surface.Surface:
     """
@@ -458,10 +443,12 @@ class ImageResource:
     """
     def __init__(self,
                  image_id: str,
-                 location: Union[PackageResource, str]):
+                 location: Union[PackageResource, str],
+                 premultiplied: bool):
         self.image_id = image_id
         self.location = location
         self.loaded_surface: Optional[pygame.Surface] = None
+        self.is_file_premultiplied = premultiplied
 
     def load(self) -> Union[Exception, None]:
         """
@@ -488,8 +475,8 @@ def load(self) -> Union[Exception, None]:
                                           str(self.location))
 
         # perform pre-multiply alpha operation
-        if error is None and self.loaded_surface is not None:
-            premul_alpha_surface(self.loaded_surface)
+        if error is None and self.loaded_surface is not None and not self.is_file_premultiplied:
+            self.loaded_surface = self.loaded_surface.premul_alpha()
 
         return error
 

pygame_gui/elements/ui_image.py

@@ -5,7 +5,6 @@
 from pygame_gui.core import ObjectID
 from pygame_gui.core.interfaces import IContainerLikeInterface, IUIManagerInterface
 from pygame_gui.core import UIElement
-from pygame_gui.core.utility import premul_alpha_surface
 from pygame_gui.core.gui_type_hints import Coordinate, RectLike
 
 
@@ -94,7 +93,7 @@ def set_image(self,
         """
         image_surface = new_image.convert_alpha()
         if not image_is_alpha_premultiplied:
-            image_surface = premul_alpha_surface(image_surface)
+            image_surface = image_surface.premul_alpha()
         if (image_surface.get_width() != self.rect.width or
                 image_surface.get_height() != self.rect.height):
             self.original_image = image_surface

pygame_gui/elements/ui_text_entry_line.py

@@ -403,6 +403,8 @@ def focus(self):
                 self.drawable_shape.set_text(self.text)
                 self.drawable_shape.text_box_layout.set_cursor_position(self.edit_position)
                 self.drawable_shape.apply_active_text_changes()
+        self.drawable_shape.text_box_layout.turn_on_cursor()
+        self.redraw()
 
     def process_event(self, event: pygame.event.Event) -> bool:
         """
@@ -568,6 +570,8 @@ def _process_action_key_event(self, event: pygame.event.Event) -> bool:
                     self.drawable_shape.text_box_layout.backspace_at_cursor()
                     self.drawable_shape.text_box_layout.set_cursor_position(self.edit_position)
                     self.drawable_shape.apply_active_text_changes()
+                    if len(self.text) == 0:
+                        self.redraw()
             consumed_event = True
         elif event.key == pygame.K_DELETE:
             if abs(self.select_range[0] - self.select_range[1]) > 0: