Shadows go brrr

project/resources/SuperSimpleDiffuse.fx

@@ -1,35 +1,41 @@
+// Global parameters
+SamplerState gShadowSampler : ShadowSampler;
+SamplerState gShadowSampler2 : ShadowSampler {
+    Filter = MIN_MAG_MIP_POINT;
+    AddressU = CLAMP;
+    AddressV = CLAMP;
+    ComparisonFunc = LESS_EQUAL;
+};
+texture2D gShadowMap : ShadowMap;
+float4x4 gLightViewProj : LightViewProjection;
+
+DepthStencilState ShadowDepthStencilState
+{
+    DepthEnable = true;
+    DepthWriteMask = ALL;       // Write depth to the shadow map
+    DepthFunc = LESS_EQUAL;     // Compare depth in the shadow map
+    StencilEnable = false;      // We don't need stencil operations here
+};
+
 SamplerState gSampleState : SampleState;
 RasterizerState gRasterizerState : RastState;
 
-// Transformations
 float4x4 gWorldViewProj : WorldViewProjection;
 float4x4 gWorldMatrix : WorldMatrix;
-float4x4 gLightViewProj : LightViewProjection;
 
-// Textures
 texture2D gDiffuseMap : DiffuseMap;
 texture2D gNormalMap : Normal;
 texture2D gSpecularMap : Specular;
 texture2D gGlossMap : Gloss;
-texture2D gShadowMap : ShadowMap;
 
-// Light properties
 float3 gLightDirection : LightDirection;
 float3 gLightColor : LightColor;
 float3 gCameraPosition : CameraPosition;
 bool gUseNormal : UseNormal;
 
-// Constants
 static const float3 gAmbient = float3(.03f, .03f, .03f);
-static const float gLightIntensity = 7.f;
-static const float PI = 3.14159f;
-static const float gSpecularReflectance = 1.f;
-static const float gShininess = 25.f;
 
-// Shadow bias to reduce artifacts
-static const float gShadowBias = 0.005f;
-
-// Input/Output structures
+// Input output structures
 struct VS_INPUT {
     float3 Position : POSITION;
     float2 TexCoord : TEXCOORD;
@@ -43,66 +49,90 @@ struct VS_OUTPUT {
     float2 TexCoord : TEXCOORD;
     float3 Normal : NORMAL;
     float3 Tangent : TANGENT;
-    float4 LightPosition : TEXCOORD1;
+    float4 ShadowCoord : SHADOWCOORD;  // Add this to store shadow map coordinates
 };
 
+// Vertex shader
 VS_OUTPUT VS(VS_INPUT input) {
     VS_OUTPUT output = (VS_OUTPUT)0;
 
-    output.Position = mul(float4(input.Position, 1.f), gWorldViewProj);
     output.WorldPosition = mul(float4(input.Position, 1.f), gWorldMatrix);
-    output.TexCoord = input.TexCoord;
-    output.Normal = mul(input.Normal, (float3x3)gWorldMatrix);
-    output.Tangent = mul(input.Tangent, (float3x3)gWorldMatrix);
-    output.LightPosition = mul(float4(input.Position, 1.f), gLightViewProj);
+    output.Position = mul(float4(input.Position, 1.f), gWorldViewProj);
 
+
+    output.TexCoord = input.TexCoord;
+    output.Normal = mul(input.Normal, (float3x3) gWorldMatrix);
+    output.Tangent = mul(input.Tangent, (float3x3) gWorldMatrix);
+
+    // Calculate shadow map coordinates
+    // lightSpaceMatrix * vec4(vs_out.FragPos, 1.0);
+    output.ShadowCoord = mul(float4(input.Position, 1.f) , gLightViewProj);
     return output;
 }
 
-float ShadowCalculation(float4 lightPos) {
-    // Transform light position to shadow map space
-    float2 shadowCoord = lightPos.xy / lightPos.w;
-    shadowCoord = shadowCoord * 0.5f + 0.5f;
+// Shadow sampling function
+float ShadowCalculation(float4 shadowCoord) {
+    // Normalize the depth by dividing by the w component
+    float3 projCoord = shadowCoord.xyz / shadowCoord.w;
 
+    // Convert from [-1, 1] to [0, 1]
+    float2 UVCoords;
+    UVCoords.x = 0.5f * projCoord.x + 0.5f;
+    UVCoords.y = -0.5f * projCoord.y + 0.5f;
+//     float z = 0.5 * projCoord.z + 0.5;
+    float z = projCoord.z;
     // Sample the shadow map
-    float shadowDepth = gShadowMap.Sample(gSampleState, shadowCoord).r;
+    float shadowDepth = gShadowMap.Sample(gShadowSampler2, UVCoords.xy).r;
+
+    float bias = 0.0025f;
+
+//     float bias = max(0.05 * (1.0 - dot(normal, lightDir)), 0.005);
+
+//     return gShadowMap.Sample(gShadowSampler2, UVCoords.xy).r;
+    // Check if the current fragment is in shadow
+    if (shadowDepth + bias < z)
+        return 0.5f;
+    else
+        return 1.0f;
 
-    // Compare depth and apply bias
-    if (shadowDepth + gShadowBias < lightPos.z / lightPos.w) {
-        return 0.0f; // In shadow
-    }
-    return 1.0f; // Not in shadow
 }
 
+// Pixel shader
 float4 PS(VS_OUTPUT input) : SV_TARGET {
-    // Normalize inputs
-    float3 normal = normalize(input.Normal);
-    float3 lightDir = normalize(gLightDirection);
+    // Check if gDiffuseMap sample has a valid value, otherwise render red
+//     if (gDiffuseMap.Sample(gSampleState, input.TexCoord).a == 0.f)
+//         return float4(1.f, 0.f, 0.f, 1.f);
 
-    // Diffuse lighting
-    float NdotL = max(dot(normal, -lightDir), 0.0f);
-    float3 diffuse = gLightColor * NdotL;
+//     return float4(Shade(input), 1.0f);  // Use the shading function with shadow
 
-    // Shadows
-    float shadowFactor = ShadowCalculation(input.LightPosition);
+//     return gShadowMap.Sample(gShadowSampler, input.ShadowCoord.xy / input.ShadowCoord.w);  // Sample shadow map
 
-    // Ambient + Diffuse * Shadow
-    float3 finalColor = gAmbient + (diffuse * shadowFactor);
-//     float3 finalColor = float3(shadowFactor,shadowFactor,shadowFactor);
+    float shadowFactor = ShadowCalculation(input.ShadowCoord);
 
+    float3 diffuseColor = gDiffuseMap.Sample(gSampleState, input.TexCoord).rgb;
+
+    float3 finalColor = float3(1.f, 1.f, 1.f) * shadowFactor;
+    finalColor += gAmbient;
+
+
+//     return float4(shadowDepth,shadowDepth,shadowDepth, 1.0f);
     return float4(finalColor, 1.0f);
+//     return gShadowMap.Sample(gShadowSampler, input.TexCoord);  // Sample shadow map
 }
 
-DepthStencilState gDepthStencilState {
+// DepthStencilState
+DepthStencilState gDepthStencilState
+{
     DepthEnable = true;
     DepthWriteMask = ALL;
     DepthFunc = LESS;
     StencilEnable = true;
 };
 
+// Technique
 technique11 DefaultTechnique {
     pass P0 {
-        SetDepthStencilState(gDepthStencilState, 0);
+        SetDepthStencilState(ShadowDepthStencilState, 0);
         SetRasterizerState(gRasterizerState);
         SetVertexShader(CompileShader(vs_5_0, VS()));
         SetGeometryShader(NULL);