public static Vertex2D BuildVertex2D(Vertex vertex, Matrix4 transMat, Vector3 cameraPos, List <IPosLight> lights, int w, int h)
{
Vertex2D result = default(Vertex2D);
SoftDevice device = SoftDevice.Default;
if (null == device)
{
return(result);
}
// 将3d坐标投影到2d空间;
result = ProjectToScreen(vertex.position, transMat, (float)w, (float)h);
// 顶点光照;
LightUtil.ApplyVertexLightings(lights, cameraPos, vertex.worldPosition, vertex.worldNormal, ref result);
// 填充顶点信息;
result.FillRenderData(vertex.uv0, vertex.color, device.PerspectiveCorrection);
return(result);
}
private static void _PixelPragma(Texture tex, int y,
Vertex2D pa, Vertex2D pb, Vertex2D pc, Vertex2D pd, AddPixelHandler handler)
{
// 计算y位置上横向扫描线的起始和结束;
SoftDevice device = SoftDevice.Default;
if (null == device)
{
return;
}
HorizonScanLine scanLine = default(HorizonScanLine);
if (!HorizonScanLine.InterpolateWithVertex2D(y, pa, pb, pc, pd, LightUtil.enableLightings, ref scanLine))
{
return;
}
int leftX = scanLine.left;
int rightX = scanLine.right;
// 有可能出现pb.x > pd.x的情况，这里做下容错;
if (leftX > rightX)
{
scanLine.SwapLeftRight();
}
// 开始横向扫描生成像素点;
bool usePerZ = device.PerspectiveCorrection;
float invxLength = scanLine.InvLength;
Vector2 uv = Vector2.zero;
Color surfaceColor = Color.Zero;
for (var x = leftX; x < rightX; x++)
{
float gradient = (float)(x - leftX) * invxLength;
if (gradient < 0)
{
gradient = 0;
}
else if (gradient > 1)
{
gradient = 1;
}
float z = scanLine.leftZ + (scanLine.rightZ - scanLine.leftZ) * gradient;
// 提前做ztest;
if (!device.ZTest(x, y, z))
{
continue;
}
float invZ = 0f;
if (z <= MathUtil.Epsilon && z >= -MathUtil.Epsilon)
{
invZ = 1f;
}
else
{
invZ = 1f / z;
}
// 纹理映射;
if (MaterialManager.enableTextures)
{
if (null != tex)
{
uv = scanLine.leftUV + (scanLine.rightUV - scanLine.leftUV) * gradient;
// 这里使用透视修正后，离的足够近也会出问题;
if (usePerZ)
{
surfaceColor = tex.GetColor(uv.x * invZ, uv.y * invZ);
}
else
{
surfaceColor = tex.GetColor(uv.x, uv.y);
}
}
}
else
{
surfaceColor = scanLine.leftColor + (scanLine.rightColor - scanLine.leftColor) * gradient;
}
if (LightUtil.enableLightings)
{
Color diffuse = MathUtil.Interpolate(scanLine.leftDiffuse, scanLine.rightDiffuse, gradient);
if (usePerZ)
{
diffuse *= invZ;
}
surfaceColor = Color.Multiply(surfaceColor, diffuse);
}
if (null != handler)
{
handler(x, y, z, surfaceColor);
}
}
}
