[d3d9] Handle unbound textures in fixed function shaders

src/d3d9/d3d9_device.cpp

@@ -6661,6 +6661,8 @@ namespace dxvk {
             break;
         }
 
+        stage.TextureBound = m_state.textures[idx] != nullptr ? 1 : 0;
+
         stage.ColorOp = data[DXVK_TSS_COLOROP];
         stage.AlphaOp = data[DXVK_TSS_ALPHAOP];
 

src/d3d9/d3d9_fixed_function.cpp

@@ -1545,9 +1545,11 @@ namespace dxvk {
     uint32_t current = diffuse;
     // Temp starts off as equal to vec4(0)
     uint32_t temp  = m_module.constvec4f32(0.0f, 0.0f, 0.0f, 0.0f);
-    
+
     uint32_t texture = m_module.constvec4f32(0.0f, 0.0f, 0.0f, 1.0f);
 
+    uint32_t unboundTextureConstId = m_module.constvec4f32(0.0f, 0.0f, 0.0f, 1.0f);
+
     for (uint32_t i = 0; i < caps::TextureStageCount; i++) {
       const auto& stage = m_fsKey.Stages[i].Contents;
 
@@ -1706,7 +1708,11 @@ namespace dxvk {
             reg = temp;
             break;
           case D3DTA_TEXTURE:
-            reg = GetTexture();
+            if (stage.TextureBound != 0) {
+              reg = GetTexture();
+            } else {
+              reg = unboundTextureConstId;
+            }
             break;
           case D3DTA_TFACTOR:
             reg = m_ps.constants.textureFactor;

src/d3d9/d3d9_fixed_function.h

@@ -150,6 +150,8 @@ namespace dxvk {
 
         uint32_t     ProjectedCount : 3;
 
+        uint32_t     TextureBound : 1;
+
         // Included in here, read from Stage 0 for packing reasons
         // Affects all stages.
         uint32_t     GlobalSpecularEnable : 1;