Backends: Rework blending equation to preserve alpha in output buffer accross all backends. (#2693, #2764, #2766, #2873, #3447, #3813, #3816)

Some of the viewport ideas from #2766 are not in there yet (e.g. Vulkan: setting compositeAlpha based on cap.supportedCompositeAlpha)
This commit is contained in:
ocornut
2021-02-17 19:29:07 +01:00
parent 27a5bdb916
commit bda12e5fdd
11 changed files with 31 additions and 14 deletions

View File

@ -15,6 +15,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2021-02-18: Change blending equation to preserve alpha in output buffer.
// 2020-08-10: Inputs: Fixed horizontal mouse wheel direction.
// 2019-12-05: Inputs: Added support for ImGuiMouseCursor_NotAllowed mouse cursor.
// 2019-07-21: Inputs: Added mapping for ImGuiKey_KeyPadEnter.
@ -68,7 +69,7 @@ struct ImDrawVertAllegro
static void ImGui_ImplAllegro5_SetupRenderState(ImDrawData* draw_data)
{
// Setup blending
al_set_blender(ALLEGRO_ADD, ALLEGRO_ALPHA, ALLEGRO_INVERSE_ALPHA);
al_set_separate_blender(ALLEGRO_ADD, ALLEGRO_ALPHA, ALLEGRO_INVERSE_ALPHA, ALLEGRO_ADD, ALLEGRO_ONE, ALLEGRO_INVERSE_ALPHA);
// Setup orthographic projection matrix
// Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right).