home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Introduction to 3D Game …ogramming with DirectX 12
/
Introduction-to-3D-Game-Programming-with-DirectX-12.ISO
/
Code.Textures
/
Chapter 12 The Geometry Shader
/
TreeBillboards
/
Shaders
/
TreeSprite.hlsl
< prev
Wrap
Text File
|
2016-03-02
|
6KB
|
209 lines
//***************************************************************************************
// TreeSprite.hlsl by Frank Luna (C) 2015 All Rights Reserved.
//***************************************************************************************
// Defaults for number of lights.
#ifndef NUM_DIR_LIGHTS
#define NUM_DIR_LIGHTS 3
#endif
#ifndef NUM_POINT_LIGHTS
#define NUM_POINT_LIGHTS 0
#endif
#ifndef NUM_SPOT_LIGHTS
#define NUM_SPOT_LIGHTS 0
#endif
// Include structures and functions for lighting.
#include "LightingUtil.hlsl"
Texture2DArray gTreeMapArray : register(t0);
SamplerState gsamPointWrap : register(s0);
SamplerState gsamPointClamp : register(s1);
SamplerState gsamLinearWrap : register(s2);
SamplerState gsamLinearClamp : register(s3);
SamplerState gsamAnisotropicWrap : register(s4);
SamplerState gsamAnisotropicClamp : register(s5);
// Constant data that varies per frame.
cbuffer cbPerObject : register(b0)
{
float4x4 gWorld;
float4x4 gTexTransform;
};
// Constant data that varies per material.
cbuffer cbPass : register(b1)
{
float4x4 gView;
float4x4 gInvView;
float4x4 gProj;
float4x4 gInvProj;
float4x4 gViewProj;
float4x4 gInvViewProj;
float3 gEyePosW;
float cbPerObjectPad1;
float2 gRenderTargetSize;
float2 gInvRenderTargetSize;
float gNearZ;
float gFarZ;
float gTotalTime;
float gDeltaTime;
float4 gAmbientLight;
float4 gFogColor;
float gFogStart;
float gFogRange;
float2 cbPerObjectPad2;
// Indices [0, NUM_DIR_LIGHTS) are directional lights;
// indices [NUM_DIR_LIGHTS, NUM_DIR_LIGHTS+NUM_POINT_LIGHTS) are point lights;
// indices [NUM_DIR_LIGHTS+NUM_POINT_LIGHTS, NUM_DIR_LIGHTS+NUM_POINT_LIGHT+NUM_SPOT_LIGHTS)
// are spot lights for a maximum of MaxLights per object.
Light gLights[MaxLights];
};
cbuffer cbMaterial : register(b2)
{
float4 gDiffuseAlbedo;
float3 gFresnelR0;
float gRoughness;
float4x4 gMatTransform;
};
struct VertexIn
{
float3 PosW : POSITION;
float2 SizeW : SIZE;
};
struct VertexOut
{
float3 CenterW : POSITION;
float2 SizeW : SIZE;
};
struct GeoOut
{
float4 PosH : SV_POSITION;
float3 PosW : POSITION;
float3 NormalW : NORMAL;
float2 TexC : TEXCOORD;
uint PrimID : SV_PrimitiveID;
};
VertexOut VS(VertexIn vin)
{
VertexOut vout;
// Just pass data over to geometry shader.
vout.CenterW = vin.PosW;
vout.SizeW = vin.SizeW;
return vout;
}
// We expand each point into a quad (4 vertices), so the maximum number of vertices
// we output per geometry shader invocation is 4.
[maxvertexcount(4)]
void GS(point VertexOut gin[1],
uint primID : SV_PrimitiveID,
inout TriangleStream<GeoOut> triStream)
{
//
// Compute the local coordinate system of the sprite relative to the world
// space such that the billboard is aligned with the y-axis and faces the eye.
//
float3 up = float3(0.0f, 1.0f, 0.0f);
float3 look = gEyePosW - gin[0].CenterW;
look.y = 0.0f; // y-axis aligned, so project to xz-plane
look = normalize(look);
float3 right = cross(up, look);
//
// Compute triangle strip vertices (quad) in world space.
//
float halfWidth = 0.5f*gin[0].SizeW.x;
float halfHeight = 0.5f*gin[0].SizeW.y;
float4 v[4];
v[0] = float4(gin[0].CenterW + halfWidth*right - halfHeight*up, 1.0f);
v[1] = float4(gin[0].CenterW + halfWidth*right + halfHeight*up, 1.0f);
v[2] = float4(gin[0].CenterW - halfWidth*right - halfHeight*up, 1.0f);
v[3] = float4(gin[0].CenterW - halfWidth*right + halfHeight*up, 1.0f);
//
// Transform quad vertices to world space and output
// them as a triangle strip.
//
float2 texC[4] =
{
float2(0.0f, 1.0f),
float2(0.0f, 0.0f),
float2(1.0f, 1.0f),
float2(1.0f, 0.0f)
};
GeoOut gout;
[unroll]
for(int i = 0; i < 4; ++i)
{
gout.PosH = mul(v[i], gViewProj);
gout.PosW = v[i].xyz;
gout.NormalW = look;
gout.TexC = texC[i];
gout.PrimID = primID;
triStream.Append(gout);
}
}
float4 PS(GeoOut pin) : SV_Target
{
float3 uvw = float3(pin.TexC, pin.PrimID%3);
float4 diffuseAlbedo = gTreeMapArray.Sample(gsamAnisotropicWrap, uvw) * gDiffuseAlbedo;
#ifdef ALPHA_TEST
// Discard pixel if texture alpha < 0.1. We do this test as soon
// as possible in the shader so that we can potentially exit the
// shader early, thereby skipping the rest of the shader code.
clip(diffuseAlbedo.a - 0.1f);
#endif
// Interpolating normal can unnormalize it, so renormalize it.
pin.NormalW = normalize(pin.NormalW);
// Vector from point being lit to eye.
float3 toEyeW = gEyePosW - pin.PosW;
float distToEye = length(toEyeW);
toEyeW /= distToEye; // normalize
// Light terms.
float4 ambient = gAmbientLight*diffuseAlbedo;
const float shininess = 1.0f - gRoughness;
Material mat = { diffuseAlbedo, gFresnelR0, shininess };
float3 shadowFactor = 1.0f;
float4 directLight = ComputeLighting(gLights, mat, pin.PosW,
pin.NormalW, toEyeW, shadowFactor);
float4 litColor = ambient + directLight;
#ifdef FOG
float fogAmount = saturate((distToEye - gFogStart) / gFogRange);
litColor = lerp(litColor, gFogColor, fogAmount);
#endif
// Common convention to take alpha from diffuse albedo.
litColor.a = diffuseAlbedo.a;
return litColor;
}