// 顶点数据差值
public static Vertex LerpVertexData(Vertex left, Vertex right, float t)
{
Vertex result = new Vertex();
// 对z值进行插值
result.pos.Z = MathF.LerpFloat(left.pos.Z, right.pos.Z, t);
// 对颜色属性进行插值
result.color = Color01.LerpColor(left.color, right.color, t);
// 对uv进行插值(此处插值不正确,对于投影变换
// 需进行 透视插值矫正)
result.u = MathF.LerpFloat(left.u, right.u, t);
result.v = MathF.LerpFloat(left.v, right.v, t);
// 对法线进行插值
result.normal = Vector3.LerpVector3(left.normal, right.normal, t);
// 对切线进行插值
result.tangent = Vector3.LerpVector3(left.tangent, right.tangent, t);
// MVP矩阵
result.mMatrix = left.mMatrix;
result.vMatrix = left.vMatrix;
result.pMatrix = left.pMatrix;
return(result);
}
public Vertex(Vector3 pos, Color01 c, float u, float v)
{
this.pos = pos;
this.color = c;
this.u = u;
this.v = v;
// 一并初始化
this.modelSpacePos = pos;
}
/// <summary>
/// 根据uv值对一个位图进行采样
///
/// 采用Clamp模式对位图进行采样（即当uv大于1或小于0时，直接进行截断）
/// </summary>
/// <param name="texture2D"></param>
/// <param name="u"></param>
/// <param name="v"></param>
/// <returns></returns>
public static Color01 Tex2D(
Bitmap texture2D,
float u, float v,
TextureFilterMode filterMode = TextureFilterMode.Point,
TextureWrapMode wrapMode = TextureWrapMode.Clamp)
{
// 根据纹理采样模式设置uv
switch (wrapMode)
{
case TextureWrapMode.Clamp:
// 采用Clamp模式，直接对uv进行截断
u = MathF.Clamp01(u);
v = MathF.Clamp01(v);
break;
case TextureWrapMode.Repeat:
// 采用Repeat模式,uv只取小数点部位
u = MathF.Frac(u);
v = MathF.Frac(v);
break;
}
Color01 finalColor = Color01.White;
// 根据纹理过滤模式设置当前uv点的像素颜色
switch (filterMode)
{
case TextureFilterMode.Point:
// 点采样模式(最近邻采样),
// 选取距离当前采样点(u,v)最近的纹素作为当前像素的颜色
int tx = (int)(u * (texture2D.Width - 1));
int ty = (int)(v * (texture2D.Height - 1));
tx = MathF.Clamp(tx, 0, texture2D.Width);
ty = MathF.Clamp(ty, 0, texture2D.Height);
Color color = texture2D.GetPixel(tx, ty);
finalColor = Color01.FromColor(color);
break;
case TextureFilterMode.Bilinear:
// 双线性采样
// (不开启MipMap时,会作用于Level 0(即原始图片大小),
// 开启后会选择图片大小与3D图形大小最相近的一层)
// 选取与当前采样区域邻近的四个纹素的均值作为本次采样的结果
break;
}
return(finalColor);
}
/// <summary>
/// 根据uv值对一个位图进行采样
///
/// 采用Clamp模式对位图进行采样（即当uv大于1或小于0时，直接进行截断）
/// </summary>
/// <param name="texture2D"></param>
/// <param name="u"></param>
/// <param name="v"></param>
/// <returns></returns>
public static Color01 Tex2D(Bitmap texture2D, float u, float v)
{
// 采用Clamp模式，直接对uv进行截断
u = MathF.Clamp01(u);
v = MathF.Clamp01(v);
int tx = (int)(u * (texture2D.Width - 1));
int ty = (int)(v * (texture2D.Height - 1));
tx = MathF.Clamp(tx, 0, texture2D.Width);
ty = MathF.Clamp(ty, 0, texture2D.Height);
Color color = texture2D.GetPixel(tx, ty);
Color01 color01 = Color01.FromColor(color);
return(color01);
}
