2024-03-28 10:14:25 +01:00

85 lines
2.5 KiB
PostScript

////////////////////////////////////////////////////////////////////////////////
// Filename: light.ps
////////////////////////////////////////////////////////////////////////////////
/////////////
// GLOBALS //
/////////////
Texture2D shaderTexture : register(t0);
SamplerState SampleType : register(s0);
cbuffer LightBuffer
{
float4 ambientColor;
float4 diffuseColor;
float3 lightDirection;
float padding;
float specularPower;
float4 specularColor;
};
//////////////
// TYPEDEFS //
//////////////
struct PixelInputType
{
float4 position : SV_POSITION;
float2 tex : TEXCOORD0;
float3 normal : NORMAL;
float3 viewDirection : TEXCOORD1;
};
////////////////////////////////////////////////////////////////////////////////
// Pixel Shader
////////////////////////////////////////////////////////////////////////////////
float4 LightPixelShader(PixelInputType input) : SV_TARGET
{
float4 textureColor;
float3 lightDir;
float lightIntensity;
float4 color;
float3 reflection;
float4 specular;
// Sample the pixel color from the texture using the sampler at this texture coordinate location.
textureColor = shaderTexture.Sample(SampleType, input.tex);
// Set the default output color to the ambient light value for all pixels.
color = ambientColor;
// Initialize the specular color.
specular = float4(0.0f, 0.0f, 0.0f, 0.0f);
// Invert the light direction for calculations.
lightDir = -lightDirection;
// Calculate the amount of light on this pixel.
lightIntensity = saturate(dot(input.normal, lightDir));
if(lightIntensity > 0.0f)
{
// Determine the final diffuse color based on the diffuse color and the amount of light intensity.
color += (diffuseColor * lightIntensity);
// Saturate the ambient and diffuse color.
color = saturate(color);
// Calculate the reflection vector based on the light intensity, normal vector, and light direction.
reflection = normalize(2.0f * lightIntensity * input.normal - lightDir);
// Determine the amount of specular light based on the reflection vector, viewing direction, and specular power.
specular = pow(saturate(dot(reflection, input.viewDirection)), specularPower);
}
// Multiply the texture pixel and the final diffuse color to get the final pixel color result.
color = color * textureColor;
// Add the specular component last to the output color.
color = saturate(color + specular);
return color;
}