void DrawEntity(Entity entity)
{
Mesh mesh = entity.meshFilter.mesh;
Transform objectTransform = entity.transform;
Texture2D mainTex = entity.mainTex;
for (int i = 0; i < mesh.triangles.Length; i += 3)
{
int a_index = mesh.triangles[i];
int b_index = mesh.triangles[i + 1];
int c_index = mesh.triangles[i + 2];
TriangleAttribute <Color> colors = new TriangleAttribute <Color>(Color.red, Color.green, Color.blue);
TriangleAttribute <Vector2> uvs = new TriangleAttribute <Vector2>(mesh.uv[a_index], mesh.uv[b_index], mesh.uv[c_index]);
Vector4 a = V4Point(mesh.vertices[a_index]);
Vector4 b = V4Point(mesh.vertices[b_index]);
Vector4 c = V4Point(mesh.vertices[c_index]);
m_Transform m_objectTransform = new m_Transform();
m_objectTransform.CopyFromTransform(objectTransform);
a = m_objectTransform.TransformPoint(a);
b = m_objectTransform.TransformPoint(b);
c = m_objectTransform.TransformPoint(c);
TriangleAttribute <Vector3> pos_worlds = new TriangleAttribute <Vector3>(a, b, c);
TriangleAttribute <Vector3> normals =
new TriangleAttribute <Vector3>(
m_objectTransform.TransformDirection(mesh.normals[a_index]),
m_objectTransform.TransformDirection(mesh.normals[b_index]),
m_objectTransform.TransformDirection(mesh.normals[c_index]));
m_Transform cam_t = new m_Transform();
cam_t.CopyFromTransform(cam.transform);
a = cam_t.InverseTransformPoint(a);
b = cam_t.InverseTransformPoint(b);
c = cam_t.InverseTransformPoint(c);
Matrix4x4 p = GetProjectionMatrix(cam);
Matrix4x4 negetive = Matrix4x4.identity;
negetive.m22 = -1;
Matrix4x4 total = p * negetive;
a = ClipSpaceToScreenSpace(total * V4Point(a), pixelWidth, pixelHeight);
b = ClipSpaceToScreenSpace(total * V4Point(b), pixelWidth, pixelHeight);
c = ClipSpaceToScreenSpace(total * V4Point(c), pixelWidth, pixelHeight);
a.z = a.w;
b.z = b.w;
c.z = c.w;
Triangle3D triangle = new Triangle3D(a, b, c); //z值为摄像机空间z坐标
DrawTriangle(colorBuffer, triangle, colors, uvs, pos_worlds, normals, mainTex);
}
}
void TestRenderer()
{
Helper.display = false;
List <Triangle3D> ts = bsp.GetSquence(cam.transform.position);
Helper.DisplayTriangleList(ts, "bsp");
for (int i = 0; i < ts.Count; i++)
{
if (!FaceCulling(ts[i].normal, cam.transform.forward))
{
ts.RemoveAt(i);
i--;
}
}
Helper.DisplayTriangleList(ts, "face culling");
//观察坐标系，左手坐标系
m_Transform cam_t = new m_Transform();
cam_t.CopyFromTransform(cam.transform);
for (int i = 0; i < ts.Count; i++)
{
Triangle3D t = ts[i];
t.a = cam_t.InverseTransformPoint(t.a);
t.b = cam_t.InverseTransformPoint(t.b);
t.c = cam_t.InverseTransformPoint(t.c);
t.normal = cam_t.InverseTransformDirection(t.normal);
ts[i] = t;
}
int count = ts.Count;
for (int i = 0; i < count; i++)
{
ts.AddRange(ViewSpaceFrustrumClipping(ts[0], cam));
ts.RemoveAt(0);
}
Helper.DisplayTriangleList(ts, "Frustrum Clipping");
List <Triangle3D> ts_ScreenSpace = new List <Triangle3D>(ts.Count);
Matrix4x4 p = GetProjectionMatrix(cam);
//转换到右手坐标
Matrix4x4 negetive = Matrix4x4.identity;
negetive.m22 = -1;
Matrix4x4 total = p * negetive;
for (int i = 0; i < ts.Count; i++)
{
Triangle3D t = ts[i];
t.a = ClipSpaceToScreenSpace(total * V4Point(t.a), pixelWidth, pixelHeight);
t.b = ClipSpaceToScreenSpace(total * V4Point(t.b), pixelWidth, pixelHeight);
t.c = ClipSpaceToScreenSpace(total * V4Point(t.c), pixelWidth, pixelHeight);
ts_ScreenSpace.Add(t);
}
Helper.DisplayTriangleList(ts_ScreenSpace, "Sceen Space");
for (int i = 0; i < ts_ScreenSpace.Count; i++)
{
Triangle3D t = ts_ScreenSpace[i];
Vector2[] t2 = new Vector2[3];
t2[0] = t.a;
t2[1] = t.b;
t2[2] = t.c;
DrawTriangleScanLine(colorBuffer, t2);
}
}
