procedural-3d-engine/shaders/slang/specializationconstants/uber.slang
2025-05-03 17:33:16 +02:00

110 lines
No EOL
2.9 KiB
Text

/* Copyright (c) 2025, Sascha Willems
*
* SPDX-License-Identifier: MIT
*
*/
struct VSInput
{
float3 Pos;
float3 Normal;
float2 UV;
float3 Color;
};
struct VSOutput
{
float4 Pos : SV_POSITION;
float3 Normal;
float3 Color;
float2 UV;
float3 ViewVec;
float3 LightVec;
};
struct UBO
{
float4x4 projection;
float4x4 model;
float4 lightPos;
};
ConstantBuffer<UBO> ubo;
Sampler2D samplerColormap;
Sampler2D samplerDiscard;
// We use this constant to control the flow of the shader depending on the
// lighting model selected at pipeline creation time
[[SpecializationConstant]] const int LIGHTING_MODEL = 0;
// Parameter for the toon shading part of the shader
[[SpecializationConstant]] const int PARAM_TOON_DESATURATION = 0;
[shader("vertex")]
VSOutput vertexMain(VSInput input)
{
VSOutput output;
output.Normal = input.Normal;
output.Color = input.Color;
output.UV = input.UV;
output.Pos = mul(ubo.projection, mul(ubo.model, float4(input.Pos.xyz, 1.0)));
float4 pos = mul(ubo.model, float4(input.Pos, 1.0));
output.Normal = mul((float3x3)ubo.model, input.Normal);
float3 lPos = mul((float3x3)ubo.model, ubo.lightPos.xyz);
output.LightVec = lPos - pos.xyz;
output.ViewVec = -pos.xyz;
return output;
}
[shader("fragment")]
float4 fragmentMain(VSOutput input) : SV_TARGET
{
switch (LIGHTING_MODEL) {
case 0: // Phong
{
float3 ambient = input.Color * float3(0.25, 0.25, 0.25);
float3 N = normalize(input.Normal);
float3 L = normalize(input.LightVec);
float3 V = normalize(input.ViewVec);
float3 R = reflect(-L, N);
float3 diffuse = max(dot(N, L), 0.0) * input.Color;
float3 specular = pow(max(dot(R, V), 0.0), 32.0) * float3(0.75, 0.75, 0.75);
return float4(ambient + diffuse * 1.75 + specular, 1.0);
}
case 1: // Toon
{
float3 N = normalize(input.Normal);
float3 L = normalize(input.LightVec);
float intensity = dot(N,L);
float3 color;
if (intensity > 0.98)
color = input.Color * 1.5;
else if (intensity > 0.9)
color = input.Color * 1.0;
else if (intensity > 0.5)
color = input.Color * 0.6;
else if (intensity > 0.25)
color = input.Color * 0.4;
else
color = input.Color * 0.2;
// Desaturate a bit
color = float3(lerp(color, dot(float3(0.2126,0.7152,0.0722), color).xxx, asfloat(PARAM_TOON_DESATURATION)));
return float4(color, 1);
}
case 2: // Textured
{
float4 color = samplerColormap.Sample(input.UV).rrra;
float3 ambient = color.rgb * float3(0.25, 0.25, 0.25) * input.Color;
float3 N = normalize(input.Normal);
float3 L = normalize(input.LightVec);
float3 V = normalize(input.ViewVec);
float3 R = reflect(-L, N);
float3 diffuse = max(dot(N, L), 0.0) * color.rgb;
float specular = pow(max(dot(R, V), 0.0), 32.0) * color.a;
return float4(ambient + diffuse + specular.xxx, 1.0);
}
}
return float4(0, 0, 0, 0);
}