Pixel shader for mesh

draw.cc

ctx->PSSetShader(shaders.ps, NULL, 0);
ctx->PSSetShaderResources(0, 1, &diffuse_texture.view.p);
ctx->PSSetSamplers(0, 1, &diffuse_texture.state.p);

mesh_ps.fx

Texture2D diffuse_tex;
SamplerState sample_type;

struct pixel_input_type
{
  float4 position : SV_POSITION;
  float3 normal : NORMAL;
	float2 tex : TEXCOORD0;
};

float3 blend(float3 a, float3 b, float lo, float hi, float s)
{
	float r = hi - lo;
	s = (s - lo)/r;
	return (s <= 0 || s > 1)
	? float3(0, 0, 0)
	: lerp(a, b, s);
}

float4 pixel_shader(pixel_input_type input) : SV_TARGET
{
  float3 n = normalize(input.normal);
  float3 l = float3(0.0, 1.0, 0.0);
  float intensity = dot(n, l);
//  float3 bg = float3(102, 84, 70) / 255.0;
//  float3 mid = float3(174, 204, 182) / 255.0;
//  float3 fg = float3(222, 242, 196) / 255.0;

//  float3 diffuse
//	= blend(bg,  bg,  -1.0, -0.8, intensity)
//	+ blend(bg,  mid, -0.8,  0.0, intensity)
//	+ blend(mid, fg,   0.0,  1.0, intensity)
//	;

//  float3 diffuse = input.tex.xyx;
  float3 diffuse = diffuse_tex.Sample(sample_type, input.tex);
  return float4(0.8 * diffuse, 0.4);
}