From d13dc0ce4733f37af1356a61a6ada30e4d80170a Mon Sep 17 00:00:00 2001
From: Hans-Kristian Arntzen <post@arntzen-software.no>
Date: Tue, 16 Jun 2020 12:54:22 +0200
Subject: [PATCH] HLSL: Fix texProj in legacy HLSL.

---
 .../frag/legacy-tex-modifiers.sm30.frag       | 32 +++++++++++++++
 .../frag/legacy-tex-modifiers.sm30.frag       | 32 +++++++++++++++
 .../frag/legacy-tex-modifiers.sm30.frag       | 13 +++++++
 spirv_hlsl.cpp                                | 39 ++++++++++++-------
 4 files changed, 103 insertions(+), 13 deletions(-)
 create mode 100644 reference/opt/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag
 create mode 100644 reference/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag
 create mode 100644 shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag

diff --git a/reference/opt/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag b/reference/opt/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag
new file mode 100644
index 00000000..2af0e513
--- /dev/null
+++ b/reference/opt/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag
@@ -0,0 +1,32 @@
+uniform sampler2D uSampler;
+
+static float4 FragColor;
+static float2 vUV;
+
+struct SPIRV_Cross_Input
+{
+    float2 vUV : TEXCOORD0;
+};
+
+struct SPIRV_Cross_Output
+{
+    float4 FragColor : COLOR0;
+};
+
+void frag_main()
+{
+    float3 _23 = float3(vUV, 5.0f);
+    FragColor = tex2Dproj(uSampler, float4(_23.xy, 0.0, _23.z));
+    FragColor += tex2Dbias(uSampler, float4(vUV, 0.0, 3.0f));
+    FragColor += tex2Dlod(uSampler, float4(vUV, 0.0, 2.0f));
+    FragColor += tex2Dgrad(uSampler, vUV, 4.0f.xx, 5.0f.xx);
+}
+
+SPIRV_Cross_Output main(SPIRV_Cross_Input stage_input)
+{
+    vUV = stage_input.vUV;
+    frag_main();
+    SPIRV_Cross_Output stage_output;
+    stage_output.FragColor = float4(FragColor);
+    return stage_output;
+}
diff --git a/reference/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag b/reference/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag
new file mode 100644
index 00000000..2af0e513
--- /dev/null
+++ b/reference/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag
@@ -0,0 +1,32 @@
+uniform sampler2D uSampler;
+
+static float4 FragColor;
+static float2 vUV;
+
+struct SPIRV_Cross_Input
+{
+    float2 vUV : TEXCOORD0;
+};
+
+struct SPIRV_Cross_Output
+{
+    float4 FragColor : COLOR0;
+};
+
+void frag_main()
+{
+    float3 _23 = float3(vUV, 5.0f);
+    FragColor = tex2Dproj(uSampler, float4(_23.xy, 0.0, _23.z));
+    FragColor += tex2Dbias(uSampler, float4(vUV, 0.0, 3.0f));
+    FragColor += tex2Dlod(uSampler, float4(vUV, 0.0, 2.0f));
+    FragColor += tex2Dgrad(uSampler, vUV, 4.0f.xx, 5.0f.xx);
+}
+
+SPIRV_Cross_Output main(SPIRV_Cross_Input stage_input)
+{
+    vUV = stage_input.vUV;
+    frag_main();
+    SPIRV_Cross_Output stage_output;
+    stage_output.FragColor = float4(FragColor);
+    return stage_output;
+}
diff --git a/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag b/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag
new file mode 100644
index 00000000..30b957b2
--- /dev/null
+++ b/shaders-hlsl/frag/legacy-tex-modifiers.sm30.frag
@@ -0,0 +1,13 @@
+#version 450
+
+layout(location = 0) in vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+layout(set = 0, binding = 0) uniform sampler2D uSampler;
+
+void main()
+{
+	FragColor = textureProj(uSampler, vec3(vUV, 5.0));
+	FragColor += texture(uSampler, vUV, 3.0);
+	FragColor += textureLod(uSampler, vUV, 2.0);
+	FragColor += textureGrad(uSampler, vUV, vec2(4.0), vec2(5.0));
+}
diff --git a/spirv_hlsl.cpp b/spirv_hlsl.cpp
index cbe68d0b..d4074e7c 100644
--- a/spirv_hlsl.cpp
+++ b/spirv_hlsl.cpp
@@ -2946,24 +2946,37 @@ void CompilerHLSL::emit_texture_op(const Instruction &i, bool sparse)
 	if (proj && hlsl_options.shader_model >= 40) // Legacy HLSL has "proj" operations which do this for us.
 		coord_expr = coord_expr + " / " + to_extract_component_expression(coord, coord_components);
 
-	if (hlsl_options.shader_model < 40 && lod)
+	if (hlsl_options.shader_model < 40)
 	{
 		string coord_filler;
-		for (uint32_t size = coord_components; size < 3; ++size)
-		{
-			coord_filler += ", 0.0";
-		}
-		coord_expr = "float4(" + coord_expr + coord_filler + ", " + to_expression(lod) + ")";
-	}
+		uint32_t modifier_count = 0;
 
-	if (hlsl_options.shader_model < 40 && bias)
-	{
-		string coord_filler;
-		for (uint32_t size = coord_components; size < 3; ++size)
+		if (lod)
 		{
-			coord_filler += ", 0.0";
+			for (uint32_t size = coord_components; size < 3; ++size)
+				coord_filler += ", 0.0";
+			coord_expr = "float4(" + coord_expr + coord_filler + ", " + to_expression(lod) + ")";
+			modifier_count++;
 		}
-		coord_expr = "float4(" + coord_expr + coord_filler + ", " + to_expression(bias) + ")";
+
+		if (bias)
+		{
+			for (uint32_t size = coord_components; size < 3; ++size)
+				coord_filler += ", 0.0";
+			coord_expr = "float4(" + coord_expr + coord_filler + ", " + to_expression(bias) + ")";
+			modifier_count++;
+		}
+
+		if (proj)
+		{
+			for (uint32_t size = coord_components; size < 3; ++size)
+				coord_filler += ", 0.0";
+			coord_expr = "float4(" + coord_expr + coord_filler + ", " + to_extract_component_expression(coord, coord_components) + ")";
+			modifier_count++;
+		}
+
+		if (modifier_count > 1)
+			SPIRV_CROSS_THROW("Legacy HLSL can only use one of lod/bias/proj modifiers.");
 	}
 
 	if (op == OpImageFetch)