Fix inconsitency between Backends for RGB5A1 (#1932)

* opengl: Fix color ordering of RGB5A1

* vulkan: Fix color ordering of RGB5A1

* d3d9: Fix color ordering of RGB5A1

src/renderer_d3d9.cpp

@@ -3024,10 +3024,6 @@ namespace bgfx { namespace d3d9
 							uint32_t size = useMipSize ? mip.m_size : mipSize;
 							switch (m_textureFormat)
 							{
-							case TextureFormat::RGB5A1:
-								bimg::imageConvert(bits, 16, bx::packBgr5a1, mip.m_data, bx::unpackRgb5a1, size);
-								break;
-
 							case TextureFormat::RGBA4:
 								bimg::imageConvert(bits, 16, bx::packBgra4, mip.m_data, bx::unpackRgba4, size);
 								break;
@@ -3089,10 +3085,6 @@ namespace bgfx { namespace d3d9
 			{
 				switch (m_textureFormat)
 				{
-				case TextureFormat::RGB5A1:
-					bimg::imageConvert(dst, 16, bx::packBgr5a1, src, bx::unpackRgb5a1, rectpitch);
-					break;
-
 				case TextureFormat::RGBA4:
 					bimg::imageConvert(dst, 16, bx::packBgra4, src, bx::unpackRgba4, rectpitch);
 					break;

src/renderer_gl.cpp

@@ -265,7 +265,7 @@ namespace bgfx { namespace gl
 		{ GL_RGBA32F,                                  GL_ZERO,                                       GL_RGBA,                                     GL_RGBA,                                     GL_FLOAT,                        false }, // RGBA32F
 		{ GL_RGB565,                                   GL_ZERO,                                       GL_RGB,                                      GL_RGB,                                      GL_UNSIGNED_SHORT_5_6_5,         false }, // R5G6B5
 		{ GL_RGBA4,                                    GL_ZERO,                                       GL_RGBA,                                     GL_RGBA,                                     GL_UNSIGNED_SHORT_4_4_4_4_REV,   false }, // RGBA4
-		{ GL_RGB5_A1,                                  GL_ZERO,                                       GL_RGBA,                                     GL_RGBA,                                     GL_UNSIGNED_SHORT_1_5_5_5_REV,   false }, // RGB5A1
+		{ GL_RGB5_A1,                                  GL_ZERO,                                       GL_BGRA,                                     GL_BGRA,                                     GL_UNSIGNED_SHORT_1_5_5_5_REV,   false }, // RGB5A1
 		{ GL_RGB10_A2,                                 GL_ZERO,                                       GL_RGBA,                                     GL_RGBA,                                     GL_UNSIGNED_INT_2_10_10_10_REV,  false }, // RGB10A2
 		{ GL_R11F_G11F_B10F,                           GL_ZERO,                                       GL_RGB,                                      GL_RGB,                                      GL_UNSIGNED_INT_10F_11F_11F_REV, false }, // RG11B10F
 		{ GL_ZERO,                                     GL_ZERO,                                       GL_ZERO,                                     GL_ZERO,                                     GL_ZERO,                         false }, // UnknownDepth

src/renderer_vk.cpp

@@ -216,7 +216,7 @@ VK_IMPORT_DEVICE
 		{ VK_FORMAT_R32G32B32A32_SFLOAT,       VK_FORMAT_R32G32B32A32_SFLOAT,      VK_FORMAT_UNDEFINED,           VK_FORMAT_UNDEFINED                }, // RGBA32F
 		{ VK_FORMAT_B5G6R5_UNORM_PACK16,       VK_FORMAT_B5G6R5_UNORM_PACK16,      VK_FORMAT_UNDEFINED,           VK_FORMAT_UNDEFINED                }, // R5G6B5
 		{ VK_FORMAT_B4G4R4A4_UNORM_PACK16,     VK_FORMAT_B4G4R4A4_UNORM_PACK16,    VK_FORMAT_UNDEFINED,           VK_FORMAT_UNDEFINED                }, // RGBA4
-		{ VK_FORMAT_B5G5R5A1_UNORM_PACK16,     VK_FORMAT_B5G5R5A1_UNORM_PACK16,    VK_FORMAT_UNDEFINED,           VK_FORMAT_UNDEFINED                }, // RGB5A1
+		{ VK_FORMAT_A1R5G5B5_UNORM_PACK16,     VK_FORMAT_A1R5G5B5_UNORM_PACK16,    VK_FORMAT_UNDEFINED,           VK_FORMAT_UNDEFINED                }, // RGB5A1
 		{ VK_FORMAT_A2R10G10B10_UNORM_PACK32,  VK_FORMAT_A2R10G10B10_UNORM_PACK32, VK_FORMAT_UNDEFINED,           VK_FORMAT_UNDEFINED                }, // RGB10A2
 		{ VK_FORMAT_B10G11R11_UFLOAT_PACK32,   VK_FORMAT_B10G11R11_UFLOAT_PACK32,  VK_FORMAT_UNDEFINED,           VK_FORMAT_UNDEFINED                }, // RG11B10F
 		{ VK_FORMAT_UNDEFINED,                 VK_FORMAT_UNDEFINED,                VK_FORMAT_UNDEFINED,           VK_FORMAT_UNDEFINED                }, // UnknownDepth