I implemented directional, point and spot light. But HLSL shader does not work as I expected. There is a problem in passing light color parameter to a function. 16-byte alignment of constant buffer is correct. there is nothing wrong. All members of constant buffer are set well. I can see something wrong in registers(r0, r1, …) once it passes light color parameter to ComputeLambert(). it seems lightColor must be r#.xyz correct. but its value is stored in r0.w. I post my shader code also. Does anyone have an idea? Even I tried to find the document of hlsl function parameter specification. I could not find it.
struct VSOutput
{
float4 Position : SV_POSITION;
float3 Normal : NORMAL;
float2 TexCoord : TEXCOORD;
float4 WorldPos : WORLD_POS;
float3x3 InvTangentBasis : INV_TANGENT_BASIS;
};
struct PSOutput
{
float4 Color : SV_TARGET0;
};
cbuffer LightBuffer : register(b1)
{
float3 CameraPosition : packoffset(c0);
float3 DirLightDirection : packoffset(c1);
float3 DirLightColor : packoffset(c2);
float3 PtLightPosition : packoffset(c3);
float3 PtLightColor : packoffset(c4);
float PtLightRange : packoffset(c4.w);
float3 SptLightPosition : packoffset(c5);
float3 SptLightColor : packoffset(c6);
float SptLightRange : packoffset(c6.w);
float3 SptLightDirection : packoffset(c7);
float SptAngle : packoffset(c7.w);
}
cbuffer MaterialBuffer : register(b2)
{
float3 Diffuse : packoffset(c0);
float Alpha : packoffset(c0.w);
float3 Specular : packoffset(c1);
float Shininess : packoffset(c1.w);
}
cbuffer ConfigureBuffer : register(b3)
{
int DiffuseMapUsable : packoffset(c0.x);
int SpecularMapUsable : packoffset(c0.y);
int ShininessMapUsable : packoffset(c0.z);
int NormalMapUsable : packoffset(c0.w);
}
SamplerState ColorSmp : register(s0);
Texture2D ColorMap : register(t0);
Texture2D NormalMap : register(t1);
float3 GetLightFromDirLight(VSOutput input, float3 normal);
float3 GetLightFromPointLight(VSOutput input, float3 normal);
float3 GetLightFromSpotLight(VSOutput input, float3 normal);
// diffuse
float3 ComputeLambert(
float3 lightDir,
float3 lightColor,
float3 normal);
// specular
float3 ComputePhong(
float4 worldPos,
float3 lightDir,
float3 lightColor,
float3 normal);
PSOutput main(VSOutput input)
{
PSOutput output = (PSOutput) 0;
// Normal vector
float3 N;
if(NormalMapUsable)
{
N = NormalMap.Sample(ColorSmp, input.TexCoord).xyz * 2.0f - 1.0f;
N = mul(input.InvTangentBasis, N);
}
else
{
N = input.Normal;
}
float3 dirLight = GetLightFromDirLight(input, N);
float3 ptLight = GetLightFromPointLight(input, N);
float3 sptLight = GetLightFromSpotLight(input, N);
float4 color;
if(DiffuseMapUsable)
{
color = ColorMap.Sample(ColorSmp, input.TexCoord);
}
else
{
color = float4(1.0f, 0.0f, 0.0f, 1.0f);
}
float light = dirLight + ptLight + sptLight;
output.Color = float4(color.rgb * light, color.a * Alpha);
return output;
}
float3 GetLightFromDirLight(VSOutput input, float3 normal)
{
float3 diffuse = ComputeLambert(-DirLightDirection, DirLightColor, normal);
float3 specular = ComputePhong(input.WorldPos, -DirLightDirection, DirLightColor, normal);
return diffuse + specular;
}
float3 GetLightFromPointLight(VSOutput input, float3 normal)
{
float3 L = normalize(input.WorldPos.xyz - PtLightPosition);
float3 diffuse = ComputeLambert(L, PtLightColor, normal);
float3 specular = ComputePhong(input.WorldPos, L, PtLightColor, normal);
float dist = length(input.WorldPos.xyz - PtLightPosition);
float affect = saturate(1.0f - 1.0f / PtLightRange * dist);
affect = pow(affect, 3.0f);
diffuse *= affect;
specular *= affect;
return diffuse + specular;
}
float3 GetLightFromSpotLight(VSOutput input, float3 normal)
{
float3 L = normalize(input.WorldPos.xyz - SptLightPosition);
float3 diffuse = ComputeLambert(L, SptLightColor, normal);
float3 specular = ComputePhong(input.WorldPos, L, SptLightColor, normal);
float dist = length(input.WorldPos.wyz - SptLightPosition);
float affect = saturate(1.0f - 1.0f / SptLightRange * dist);
affect = pow(affect, 3.0f);
diffuse *= affect;
specular *= affect;
float angle = dot(L, SptLightDirection);
angle = abs(acos(angle));
affect = saturate(1.0f - 1.0f / SptAngle * angle);
affect = pow(affect, 0.5f);
diffuse *= affect;
specular *= affect;
return diffuse + specular;
}
float3 ComputeLambert
(
float3 lightDir,
float3 lightColor,
float3 normal
)
{
return lightColor * Diffuse * saturate(dot(lightDir, normal) * -1);
}
float3 ComputePhong
(
float4 worldPos,
float3 lightDir,
float3 lightColor,
float3 normal
)
{
float3 V = normalize(CameraPosition - worldPos.xyz);
float3 R = normalize(reflect(lightDir, normal));
return lightColor * Specular * pow(saturate(dot(V, R)), Shininess);
}
