Generate RGBA=R|G|B|A helper constant for ColorComponentFlags

When the misleading `all()` function was removed in #478 it also made
all color components for `ColorComponentFlags` significantly more
verbose to write, see #536.

Author: MarijnS95

ash/src/vk/bitflags.rs

@@ -241,6 +241,7 @@ impl ColorComponentFlags {
     pub const G: Self = Self(0b10);
     pub const B: Self = Self(0b100);
     pub const A: Self = Self(0b1000);
+    pub const RGBA: Self = Self(Self::R.0 | Self::G.0 | Self::B.0 | Self::A.0);
 }
 #[repr(transparent)]
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]

examples/src/bin/texture.rs

@@ -666,10 +666,7 @@ fn main() {
             src_alpha_blend_factor: vk::BlendFactor::ZERO,
             dst_alpha_blend_factor: vk::BlendFactor::ZERO,
             alpha_blend_op: vk::BlendOp::ADD,
-            color_write_mask: vk::ColorComponentFlags::R
-                | vk::ColorComponentFlags::G
-                | vk::ColorComponentFlags::B
-                | vk::ColorComponentFlags::A,
+            color_write_mask: vk::ColorComponentFlags::RGBA,
         }];
         let color_blend_state = vk::PipelineColorBlendStateCreateInfo::builder()
             .logic_op(vk::LogicOp::CLEAR)

examples/src/bin/triangle.rs

@@ -319,10 +319,7 @@ fn main() {
             src_alpha_blend_factor: vk::BlendFactor::ZERO,
             dst_alpha_blend_factor: vk::BlendFactor::ZERO,
             alpha_blend_op: vk::BlendOp::ADD,
-            color_write_mask: vk::ColorComponentFlags::R
-                | vk::ColorComponentFlags::G
-                | vk::ColorComponentFlags::B
-                | vk::ColorComponentFlags::A,
+            color_write_mask: vk::ColorComponentFlags::RGBA,
         }];
         let color_blend_state = vk::PipelineColorBlendStateCreateInfo::builder()
             .logic_op(vk::LogicOp::CLEAR)

generator/src/lib.rs

@@ -1455,9 +1455,18 @@ pub fn bitflags_impl_block(
             }
         });
 
+    let extra_consts = if ident == "ColorComponentFlags" {
+        quote!(
+            pub const RGBA: Self = Self(Self::R.0 | Self::G.0 | Self::B.0 | Self::A.0);
+        )
+    } else {
+        quote!()
+    };
+
     quote! {
         impl #ident {
             #(#variants)*
+            #extra_consts
         }
     }
 }