常用操作

• 顶点转换到投影空间

o.pos = UnityObjectToClipPos(v.vertex);
// or
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);

• uv坐标转换

sampler2D _MainTex;
float4 _MainTex_ST;
TRANSFORM_TEX(v.textcoord, _MainTex);

• 纹理采样

fixed4 col = tex2D(_MainTex, i.uv);

• 纹理尺寸
  默认存储在float4变量 {TextureName}_TexelSize 中
  x contains 1.0/width
  y contains 1.0/height
  z contains width
  w contains height

float4 _MainTexture_TexelSize;

• Texture HDR parameters
  float4 {TextureName}_HDR 存储了如何解码HDR贴图的信息