VideoCommon: add some helper functions for resource logic that generates invalid textures for when a texture isn't provided for a custom asset

Source/Core/DolphinLib.props

@@ -755,6 +755,7 @@
     <ClInclude Include="VideoCommon\Present.h" />
     <ClInclude Include="VideoCommon\RenderState.h" />
     <ClInclude Include="VideoCommon\Resources\CustomResourceManager.h" />
+    <ClInclude Include="VideoCommon\Resources\InvalidTextures.h" />
     <ClInclude Include="VideoCommon\Resources\Resource.h" />
     <ClInclude Include="VideoCommon\Resources\TextureDataResource.h" />
     <ClInclude Include="VideoCommon\Resources\TexturePool.h" />
@@ -1410,6 +1411,7 @@
     <ClCompile Include="VideoCommon\Present.cpp" />
     <ClCompile Include="VideoCommon\RenderState.cpp" />
     <ClCompile Include="VideoCommon\Resources\CustomResourceManager.cpp" />
+    <ClCompile Include="VideoCommon\Resources\InvalidTextures.cpp" />
     <ClCompile Include="VideoCommon\Resources\Resource.cpp" />
     <ClCompile Include="VideoCommon\Resources\TextureDataResource.cpp" />
     <ClCompile Include="VideoCommon\Resources\TexturePool.cpp" />

Source/Core/VideoCommon/CMakeLists.txt

@@ -150,6 +150,8 @@ add_library(videocommon
   RenderState.h
   Resources/CustomResourceManager.cpp
   Resources/CustomResourceManager.h
+  Resources/InvalidTextures.cpp
+  Resources/InvalidTextures.h
   Resources/Resource.cpp
   Resources/Resource.h
   Resources/TextureDataResource.cpp

Source/Core/VideoCommon/Resources/InvalidTextures.cpp

@@ -0,0 +1,58 @@
+// Copyright 2025 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "VideoCommon/Resources/InvalidTextures.h"
+
+#include "VideoCommon/AbstractGfx.h"
+#include "VideoCommon/TextureConfig.h"
+
+namespace VideoCommon
+{
+std::unique_ptr<AbstractTexture> CreateInvalidTransparentTexture()
+{
+  const TextureConfig tex_config{
+      1, 1, 1, 1, 1, AbstractTextureFormat::RGBA8, 0, AbstractTextureType::Texture_2D};
+  auto texture = g_gfx->CreateTexture(tex_config, "Invalid Transparent Texture");
+  const std::array<u8, 4> pixel{0, 0, 0, 0};
+  texture->Load(0, 1, 1, 1, pixel.data(), pixel.size());
+  return texture;
+}
+
+std::unique_ptr<AbstractTexture> CreateInvalidColorTexture()
+{
+  const TextureConfig tex_config{
+      1, 1, 1, 1, 1, AbstractTextureFormat::RGBA8, 0, AbstractTextureType::Texture_2D};
+  auto texture = g_gfx->CreateTexture(tex_config, "Invalid Color Texture");
+  const std::array<u8, 4> pixel{255, 0, 255, 255};
+  texture->Load(0, 1, 1, 1, pixel.data(), pixel.size());
+  return texture;
+}
+
+std::unique_ptr<AbstractTexture> CreateInvalidCubemapTexture()
+{
+#ifdef __APPLE__
+  // TODO: figure out cube map oddness on Apple (specifically Metal)
+  return nullptr;
+#else
+  const TextureConfig tex_config{
+      1, 1, 1, 6, 1, AbstractTextureFormat::RGBA8, 0, AbstractTextureType::Texture_CubeMap};
+  auto texture = g_gfx->CreateTexture(tex_config, "Invalid Cubemap Texture");
+  const std::array<u8, 4> pixel{255, 0, 255, 255};
+  for (u32 i = 0; i < tex_config.layers; i++)
+  {
+    texture->Load(0, tex_config.width, tex_config.height, 1, pixel.data(), pixel.size(), i);
+  }
+  return texture;
+#endif
+}
+
+std::unique_ptr<AbstractTexture> CreateInvalidArrayTexture()
+{
+  const TextureConfig tex_config{
+      1, 1, 1, 1, 1, AbstractTextureFormat::RGBA8, 0, AbstractTextureType::Texture_2DArray};
+  auto texture = g_gfx->CreateTexture(tex_config, "Invalid Array Texture");
+  const std::array<u8, 4> pixel{255, 0, 255, 255};
+  texture->Load(0, 1, 1, 1, pixel.data(), pixel.size());
+  return texture;
+}
+}  // namespace VideoCommon

Source/Core/VideoCommon/Resources/InvalidTextures.h

@@ -0,0 +1,16 @@
+// Copyright 2025 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <memory>
+
+#include "VideoCommon/AbstractTexture.h"
+
+namespace VideoCommon
+{
+std::unique_ptr<AbstractTexture> CreateInvalidTransparentTexture();
+std::unique_ptr<AbstractTexture> CreateInvalidColorTexture();
+std::unique_ptr<AbstractTexture> CreateInvalidCubemapTexture();
+std::unique_ptr<AbstractTexture> CreateInvalidArrayTexture();
+}  // namespace VideoCommon