private static void DrawTriangle(Vertex v1, Vertex v2, Vertex v3)
{
__ShaderName__ shader = new __ShaderName__();
//调用顶点着色shader
__CreateVSInputStruct1__
__VSOutputType__ p1 = shader.__VertexShaderName__(vi1);
__CreateVSInputStruct2__
__VSOutputType__ p2 = shader.__VertexShaderName__(vi2);
__CreateVSInputStruct3__
__VSOutputType__ p3 = shader.__VertexShaderName__(vi3);
p1 = ToScreen(p1);
p2 = ToScreen(p2);
p3 = ToScreen(p3);
//Console.WriteLine($"{p1.Position} {p2.Position} {p3.Position}");
//Console.WriteLine((p1.Position.Y - p2.Position.Y));
//排序，并调用填充函数
Sort(ref p1, ref p2, ref p3);
if (p2.Position.Y == p3.Position.Y)
{
FillFlatTriangle(p1, p2, p3, shader, false);
}
else if (p1.Position.Y == p2.Position.Y)
{
FillFlatTriangle(p3, p1, p2, shader, true);
}
else
{
float t = (p2.Position.Y - p1.Position.Y) / (p3.Position.Y - p1.Position.Y);
__VSOutputType__ p4 = Lerp(p1, p3, t);
FillFlatTriangle(p1, p2, p4, shader, false);
FillFlatTriangle(p3, p2, p4, shader, true);
}
}
private static void Swap(ref __VSOutputType__ a, ref __VSOutputType__ b)
{
__VSOutputType__ c = a;
a = b;
b = c;
}
private static void DrawFlatLine(__VSOutputType__ v1, __VSOutputType__ v2)
{
if (v1.Position.Y > Canvas.Height || v1.Position.Y < 0)
{
return;
}
if (v1.Position.X > v2.Position.X)
{
Swap(ref v1, ref v2);
}
if (v1.Position.X > Canvas.Width || v2.Position.X < 0)
{
return;
}
float x0 = v1.Position.X;
float x1 = v2.Position.X > Canvas.Width ? Canvas.Width : v2.Position.X;
float dx = v2.Position.X - x0 + 0.01f;
for (int i = (int)x0; i <= x1; i++)
{
float t = (i - x0) / dx;
__VSOutputType__ v = Lerp(v1, v2, t);
v = MulOnePerZ(v);
__FSOutputType__ o = Shader.__FragmentShaderName__(v);
Canvas.SetPixel(i, (int)(v1.Position.Y + 0.5), o.Color, v1.Position.Z);
}
}
private static void Sort(ref __VSOutputType__ v1, ref __VSOutputType__ v2, ref __VSOutputType__ v3)
{
if (v1.Position.Y > v2.Position.Y)
{
Swap(ref v1, ref v2);
}
if (v2.Position.Y > v3.Position.Y)
{
Swap(ref v2, ref v3);
}
if (v1.Position.Y > v2.Position.Y)
{
Swap(ref v1, ref v2);
}
}
private static void DrawFlatLine(__VSOutputType__ v1, __VSOutputType__ v2, __ShaderName__ shader)
{
if (v1.Position.X > v2.Position.X)
{
Swap(ref v1, ref v2);
}
float x0 = v1.Position.X;
float x1 = v2.Position.X;
//if (x0 > x1) Swap(ref x0, ref x1);
float dx = x1 - x0 + 0.01f;
//Console.WriteLine($"dx: {dx}");
for (int i = (int)x0; i <= x1; i++)
{
__FSOutputType__ o = shader.__FragmentShaderName__(Lerp(v1, v2, (i - x0) / dx));
Canvas.SetPixel(i, (int)(v1.Position.Y /*+ 0.5f*/), o.Color);
}
}
private static void FillFlatTriangle(__VSOutputType__ v1, __VSOutputType__ v2, __VSOutputType__ v3, __ShaderName__ shader, bool isFlatBottom)
{
if (isFlatBottom)
{
for (float scanlineY = v2.Position.Y; scanlineY <= v1.Position.Y; scanlineY++)
{
float t = (scanlineY - v2.Position.Y) / (v1.Position.Y - v2.Position.Y);
DrawFlatLine(Lerp(v1, v2, t), Lerp(v1, v3, t), shader);
}
}
else
{
for (float scanlineY = v1.Position.Y; scanlineY <= v2.Position.Y; scanlineY++)
{
float t = (scanlineY - v1.Position.Y) / (v2.Position.Y - v1.Position.Y);
DrawFlatLine(Lerp(v1, v2, t), Lerp(v1, v3, t), shader);
}
}
}
private static void DrawTriangle(Vertex v1, Vertex v2, Vertex v3)
{
//调用顶点着色shader
__CreateVSInputStruct1__
__VSOutputType__ p1 = Shader.__VertexShaderName__(vi1);
__CreateVSInputStruct2__
__VSOutputType__ p2 = Shader.__VertexShaderName__(vi2);
__CreateVSInputStruct3__
__VSOutputType__ p3 = Shader.__VertexShaderName__(vi3);
//转换到屏幕坐标
p1 = ToScreen(p1);
p2 = ToScreen(p2);
p3 = ToScreen(p3);
//消除畸变
p1 = MulOnePerZ(p1);
p2 = MulOnePerZ(p2);
p3 = MulOnePerZ(p3);
//排序，并调用填充函数
Sort(ref p1, ref p2, ref p3);
if (p2.Position.Y == p3.Position.Y)
{
FillFlatTriangle(p1, p2, p3, false);
}
else if (p1.Position.Y == p2.Position.Y)
{
FillFlatTriangle(p3, p1, p2, true);
}
else
{
float t = (p2.Position.Y - p1.Position.Y) / (p3.Position.Y - p1.Position.Y);
__VSOutputType__ p4 = Lerp(p1, p3, t);
FillFlatTriangle(p1, p2, p4, false);
FillFlatTriangle(p3, p2, p4, true);
}
}
//new Vector4((pos.X * (1 / pos.Z) * Renderer.Width + Renderer.Width / 2), (pos.Y * (1 / pos.Z) * Renderer.Height + Renderer.Height / 2), pos.Z, pos.W);
private static __VSOutputType__ Lerp(__VSOutputType__ a, __VSOutputType__ b, float t)
{
__LerpCode__
}
private static __VSOutputType__ ToScreen(__VSOutputType__ pos)
{
__ToScreenCode__
}
private static __VSOutputType__ MulOnePerZ(__VSOutputType__ v)
{
v.Position.W = 1 / v.Position.W;
__MulOnePerZCode__
return(v);
}
