Simplify the handling of alpha values in the color table (#11900)

This PR attempts to minimize the amount of fiddling we do with the alpha
color components, by storing all colors with a zero alpha (the default
for `COLORREF` values) and then leaving it up to the renderer to adjust
the final alpha value as required (which it was already doing anyway).

This gets rid of the `argb.h` header file, which was originally being
used to produce `COLORREF` values with custom alpha components, and thus
is no longer required. Anywhere that was using the `ARGB` macro is now
using a standard `RGB` macro with a 0 alpha.

The `Utils::SetColorTableAlpha` method has also been removed, since that
was only really used to force an alpha of 255 on all the color table
entries, which isn't necessary.

There were also a number of places where we were using
`til::color::with_alpha`, to switch alpha components back and forth
between 0 and 255, which have now been removed. Some of these were
essentially noops, because the `til::color` class already applied the
appropriate alpha changes when converting from or to a `COLORREF`. 

I've manually run a few attribute rendering tests to check that the
colors were still working correctly, and the default background color is
appropriately transparent when in acrylic mode.

Closes #11885

src/cascadia/LocalTests_SettingsModel/ColorSchemeTests.cpp

@@ -81,7 +81,6 @@ namespace SettingsModelLocalTests
         std::array<COLORREF, COLOR_TABLE_SIZE> expectedCampbellTable;
         const auto campbellSpan = gsl::make_span(expectedCampbellTable);
         Utils::InitializeColorTable(campbellSpan);
-        Utils::SetColorTableAlpha(campbellSpan, 0);
 
         for (size_t i = 0; i < expectedCampbellTable.size(); i++)
         {

src/cascadia/LocalTests_SettingsModel/TerminalSettingsTests.cpp

@@ -732,11 +732,11 @@ namespace SettingsModelLocalTests
         const auto terminalSettings4 = createTerminalSettings(activeProfiles.GetAt(4), colorSchemes);
         const auto terminalSettings5 = createTerminalSettings(activeProfiles.GetAt(5), colorSchemes);
 
-        VERIFY_ARE_EQUAL(ARGB(0, 0x12, 0x34, 0x56), terminalSettings0->CursorColor()); // from color scheme
+        VERIFY_ARE_EQUAL(RGB(0x12, 0x34, 0x56), terminalSettings0->CursorColor()); // from color scheme
         VERIFY_ARE_EQUAL(DEFAULT_CURSOR_COLOR, terminalSettings1->CursorColor()); // default
-        VERIFY_ARE_EQUAL(ARGB(0, 0x23, 0x45, 0x67), terminalSettings2->CursorColor()); // from profile (trumps color scheme)
-        VERIFY_ARE_EQUAL(ARGB(0, 0x34, 0x56, 0x78), terminalSettings3->CursorColor()); // from profile (not set in color scheme)
-        VERIFY_ARE_EQUAL(ARGB(0, 0x45, 0x67, 0x89), terminalSettings4->CursorColor()); // from profile (no color scheme)
+        VERIFY_ARE_EQUAL(RGB(0x23, 0x45, 0x67), terminalSettings2->CursorColor()); // from profile (trumps color scheme)
+        VERIFY_ARE_EQUAL(RGB(0x34, 0x56, 0x78), terminalSettings3->CursorColor()); // from profile (not set in color scheme)
+        VERIFY_ARE_EQUAL(RGB(0x45, 0x67, 0x89), terminalSettings4->CursorColor()); // from profile (no color scheme)
         VERIFY_ARE_EQUAL(DEFAULT_CURSOR_COLOR, terminalSettings5->CursorColor()); // default
     }
 

src/cascadia/LocalTests_SettingsModel/pch.h

@@ -62,7 +62,6 @@ Author(s):
 #include "til.h"
 
 // Common includes for most tests:
-#include "../../inc/argb.h"
 #include "../../inc/conattrs.hpp"
 #include "../../types/inc/utils.hpp"
 #include "../../inc/DefaultSettings.h"

src/cascadia/LocalTests_TerminalApp/pch.h

@@ -69,7 +69,6 @@ Author(s):
 #include "til.h"
 
 // Common includes for most tests:
-#include "../../inc/argb.h"
 #include "../../inc/conattrs.hpp"
 #include "../../types/inc/utils.hpp"
 #include "../../inc/DefaultSettings.h"

src/cascadia/TerminalControl/ControlCore.cpp

@@ -1101,7 +1101,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
     til::color ControlCore::BackgroundColor() const
     {
-        return til::color{ _terminal->GetColorTableEntry(TextColor::DEFAULT_BACKGROUND) }.with_alpha(0xff);
+        return _terminal->GetColorTableEntry(TextColor::DEFAULT_BACKGROUND);
     }
 
     // Method Description:

src/cascadia/TerminalControl/ControlInteractivity.cpp

@@ -3,7 +3,6 @@
 
 #include "pch.h"
 #include "ControlInteractivity.h"
-#include <argb.h>
 #include <DefaultSettings.h>
 #include <unicode.hpp>
 #include <Utf16Parser.hpp>

src/cascadia/TerminalControl/TermControl.cpp

@@ -450,7 +450,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     void TermControl::_InitializeBackgroundBrush()
     {
         auto settings{ _core.Settings() };
-        auto bgColor = til::color{ _core.FocusedAppearance().DefaultBackground() }.with_alpha(0xff);
+        auto bgColor = til::color{ _core.FocusedAppearance().DefaultBackground() };
         if (settings.UseAcrylic())
         {
             // See if we've already got an acrylic background brush

src/cascadia/TerminalCore/Terminal.cpp

@@ -6,7 +6,6 @@
 #include "../../terminal/parser/OutputStateMachineEngine.hpp"
 #include "TerminalDispatch.hpp"
 #include "../../inc/unicode.hpp"
-#include "../../inc/argb.h"
 #include "../../types/inc/utils.hpp"
 #include "../../types/inc/colorTable.hpp"
 
@@ -81,7 +80,7 @@ Terminal::Terminal() :
     _InitializeColorTable();
 
     _colorTable.at(TextColor::DEFAULT_FOREGROUND) = RGB(255, 255, 255);
-    _colorTable.at(TextColor::DEFAULT_BACKGROUND) = ARGB(0, 0, 0, 0);
+    _colorTable.at(TextColor::DEFAULT_BACKGROUND) = RGB(0, 0, 0);
     _colorTable.at(TextColor::CURSOR_COLOR) = INVALID_COLOR;
 }
 
@@ -137,12 +136,12 @@ void Terminal::UpdateSettings(ICoreSettings settings)
     }
     else
     {
-        _tabColor = til::color{ settings.TabColor().Value() }.with_alpha(0xff);
+        _tabColor = settings.TabColor().Value();
     }
 
     if (!_startingTabColor && settings.StartingTabColor())
     {
-        _startingTabColor = til::color{ settings.StartingTabColor().Value() }.with_alpha(0xff);
+        _startingTabColor = settings.StartingTabColor().Value();
     }
 
     if (_pfnTabColorChanged)
@@ -186,7 +185,7 @@ void Terminal::UpdateAppearance(const ICoreAppearance& appearance)
     // Set the default background as transparent to prevent the
     // DX layer from overwriting the background image or acrylic effect
     const til::color newBackgroundColor{ appearance.DefaultBackground() };
-    _colorTable.at(TextColor::DEFAULT_BACKGROUND) = newBackgroundColor.with_alpha(0);
+    _colorTable.at(TextColor::DEFAULT_BACKGROUND) = newBackgroundColor;
     const til::color newForegroundColor{ appearance.DefaultForeground() };
     _colorTable.at(TextColor::DEFAULT_FOREGROUND) = newForegroundColor;
     const til::color newCursorColor{ appearance.CursorColor() };
@@ -1226,8 +1225,6 @@ try
     const gsl::span<COLORREF> tableView = { _colorTable.data(), _colorTable.size() };
     // First set up the basic 256 colors
     Utils::InitializeColorTable(tableView);
-    // Then make sure all the values have an alpha of 255
-    Utils::SetColorTableAlpha(tableView, 0xff);
 }
 CATCH_LOG()
 
@@ -1311,9 +1308,7 @@ Scheme Terminal::GetColorScheme() const noexcept
     Scheme s;
 
     s.Foreground = til::color{ _colorTable.at(TextColor::DEFAULT_FOREGROUND) };
-    // Don't leak the implementation detail that our _defaultBg is stored
-    // internally without alpha.
-    s.Background = til::color{ _colorTable.at(TextColor::DEFAULT_BACKGROUND) }.with_alpha(0xff);
+    s.Background = til::color{ _colorTable.at(TextColor::DEFAULT_BACKGROUND) };
 
     // SelectionBackground is stored in the ControlAppearance
     s.CursorColor = til::color{ _colorTable.at(TextColor::CURSOR_COLOR) };
@@ -1340,10 +1335,7 @@ Scheme Terminal::GetColorScheme() const noexcept
 void Terminal::ApplyScheme(const Scheme& colorScheme)
 {
     _colorTable.at(TextColor::DEFAULT_FOREGROUND) = til::color{ colorScheme.Foreground };
-    // Set the default background as transparent to prevent the
-    // DX layer from overwriting the background image or acrylic effect
-    til::color newBackgroundColor{ colorScheme.Background };
-    _colorTable.at(TextColor::DEFAULT_BACKGROUND) = newBackgroundColor.with_alpha(0);
+    _colorTable.at(TextColor::DEFAULT_BACKGROUND) = til::color{ colorScheme.Background };
 
     _colorTable[0] = til::color{ colorScheme.Black };
     _colorTable[1] = til::color{ colorScheme.Red };

src/cascadia/UnitTests_Control/pch.h

@@ -50,7 +50,6 @@ Licensed under the MIT license.
 #include "ThrottledFunc.h"
 
 // Common includes for most tests:
-#include "../../inc/argb.h"
 #include "../../inc/conattrs.hpp"
 #include "../../types/inc/utils.hpp"
 #include "../../inc/DefaultSettings.h"

src/cascadia/UnitTests_Remoting/pch.h

@@ -44,7 +44,6 @@ Licensed under the MIT license.
 #include "til.h"
 
 // Common includes for most tests:
-#include "../../inc/argb.h"
 #include "../../inc/conattrs.hpp"
 #include "../../types/inc/utils.hpp"
 #include "../../inc/DefaultSettings.h"

src/cascadia/UnitTests_TerminalCore/ScrollTest.cpp

@@ -4,7 +4,6 @@
 #include "pch.h"
 #include <WexTestClass.h>
 
-#include <argb.h>
 #include <DefaultSettings.h>
 
 #include "../renderer/inc/DummyRenderTarget.hpp"

src/cascadia/ut_app/precomp.h

@@ -53,7 +53,6 @@ Author(s):
 #include "til.h"
 
 // Common includes for most tests:
-#include "../../inc/argb.h"
 #include "../../inc/conattrs.hpp"
 #include "../../types/inc/utils.hpp"
 #include "../../inc/DefaultSettings.h"

src/inc/argb.h

@@ -1,26 +0,0 @@
-/*++
-Copyright (c) Microsoft Corporation
-Licensed under the MIT license.
-
-Module Name:
-- argb.h
-
-Abstract:
-- Replaces the RGB macro with one that fills the highest order byte with 0xff.
-    We use this for the cascadia project, because it can have colors with an
-    alpha component. For code that is alpha-aware, include this header to make
-    RGB() fill the alpha byte. Otherwise, colors made with RGB will be transparent.
-Author(s):
-- Mike Griese (migrie) Feb 2019
---*/
-#pragma once
-
-constexpr COLORREF ARGB(const BYTE a, const BYTE r, const BYTE g, const BYTE b) noexcept
-{
-    return (a << 24) | (b << 16) | (g << 8) | (r);
-}
-
-#ifdef RGB
-#undef RGB
-#define RGB(r, g, b) (ARGB(255, (r), (g), (b)))
-#endif

src/renderer/dx/CustomTextRenderer.cpp

@@ -348,8 +348,7 @@ try
     if (!fInvert)
     {
         // Make sure to make the cursor opaque
-        RETURN_IF_FAILED(d2dContext->CreateSolidColorBrush(til::color{ OPACITY_OPAQUE | options.cursorColor },
-                                                           &brush));
+        RETURN_IF_FAILED(d2dContext->CreateSolidColorBrush(til::color{ options.cursorColor }, &brush));
     }
     else
     {

src/types/inc/colorTable.hpp

@@ -16,20 +16,4 @@ namespace Microsoft::Console::Utils
     gsl::span<const til::color> CampbellColorTable();
 
     std::optional<til::color> ColorFromXOrgAppColorName(const std::wstring_view wstr) noexcept;
-
-    // Function Description:
-    // - Fill the alpha byte of the colors in a given color table with the given value.
-    // Arguments:
-    // - table: a color table
-    // - newAlpha: the new value to use as the alpha for all the entries in that table.
-    // Return Value:
-    // - <none>
-    constexpr void SetColorTableAlpha(const gsl::span<COLORREF> table, const BYTE newAlpha) noexcept
-    {
-        const auto shiftedAlpha = newAlpha << 24;
-        for (auto& color : table)
-        {
-            WI_UpdateFlagsInMask(color, 0xff000000, shiftedAlpha);
-        }
-    }
 }