在沒有OpenGL的情況下複製OpenGL正投影行爲

我遇到了嘗試在沒有OpenGL的環境中複製OpenGL行爲的問題。在沒有OpenGL的情況下複製OpenGL正投影行爲

基本上我需要從我的程序創建的行列表中創建一個SVG文件。這些線是使用潦草的投影創建的。

我確定這些行的計算是正確的，因爲如果我嘗試使用正交投影的OpenGL上下文並將結果保存到圖像中，則圖像是正確的。

當我在沒有OpenGL的情況下使用完全相同的行時，問題就會引發。

我複製了OpenGL投影和視圖矩陣和予處理每一行點是這樣的：

3D_output_point = projection_matrix * view_matrix * 3D_input_point

，然後我計算它的屏幕（SVG文件）的位置是這樣的：

2D_point_x = (windowWidth/2) * 3D_point_x + (windowWidth/2) 
2D_point_y = (windowHeight/2) * 3D_point_y + (windowHeight/2)

我計算這樣的攝影投影矩陣：

float range = 700.0f; 
float l, t, r, b, n, f; 

l = -range; 
r = range; 
b = -range; 
t = range; 
n = -6000; 
f = 8000; 

matProj.SetValore(0, 0, 2.0f/(r - l)); 
matProj.SetValore(0, 1, 0.0f); 
matProj.SetValore(0, 2, 0.0f); 
matProj.SetValore(0, 3, 0.0f); 

matProj.SetValore(1, 0, 0.0f); 
matProj.SetValore(1, 1, 2.0f/(t - b)); 
matProj.SetValore(1, 2, 0.0f); 
matProj.SetValore(1, 3, 0.0f); 

matProj.SetValore(2, 0, 0.0f); 
matProj.SetValore(2, 1, 0.0f); 
matProj.SetValore(2, 2, (-1.0f)/(f - n)); 
matProj.SetValore(2, 3, 0.0f); 

matProj.SetValore(3, 0, -(r + l)/(r - l)); 
matProj.SetValore(3, 1, -(t + b)/(t - b)); 
matProj.SetValore(3, 2, -n/(f - n)); 
matProj.SetValore(3, 3, 1.0f);

and the vie w ^矩陣是這樣的：

CVettore position, lookAt, up; 

position.AssegnaCoordinate(rtRay->m_pCam->Vp.x, rtRay->m_pCam->Vp.y, rtRay->m_pCam->Vp.z); 
lookAt.AssegnaCoordinate(rtRay->m_pCam->Lp.x, rtRay->m_pCam->Lp.y, rtRay->m_pCam->Lp.z); 
up.AssegnaCoordinate(rtRay->m_pCam->Up.x, rtRay->m_pCam->Up.y, rtRay->m_pCam->Up.z); 

up[0] = -up[0]; 
up[1] = -up[1]; 
up[2] = -up[2]; 

CVettore zAxis, xAxis, yAxis; 
float length, result1, result2, result3; 

// zAxis = normal(lookAt - position) 
zAxis[0] = lookAt[0] - position[0]; 
zAxis[1] = lookAt[1] - position[1]; 
zAxis[2] = lookAt[2] - position[2]; 
length = sqrt((zAxis[0] * zAxis[0]) + (zAxis[1] * zAxis[1]) + (zAxis[2] * zAxis[2])); 
zAxis[0] = zAxis[0]/length; 
zAxis[1] = zAxis[1]/length; 
zAxis[2] = zAxis[2]/length; 

// xAxis = normal(cross(up, zAxis)) 
xAxis[0] = (up[1] * zAxis[2]) - (up[2] * zAxis[1]); 
xAxis[1] = (up[2] * zAxis[0]) - (up[0] * zAxis[2]); 
xAxis[2] = (up[0] * zAxis[1]) - (up[1] * zAxis[0]); 
length = sqrt((xAxis[0] * xAxis[0]) + (xAxis[1] * xAxis[1]) + (xAxis[2] * xAxis[2])); 
xAxis[0] = xAxis[0]/length; 
xAxis[1] = xAxis[1]/length; 
xAxis[2] = xAxis[2]/length; 

// yAxis = cross(zAxis, xAxis) 
yAxis[0] = (zAxis[1] * xAxis[2]) - (zAxis[2] * xAxis[1]); 
yAxis[1] = (zAxis[2] * xAxis[0]) - (zAxis[0] * xAxis[2]); 
yAxis[2] = (zAxis[0] * xAxis[1]) - (zAxis[1] * xAxis[0]); 

// -dot(xAxis, position) 
result1 = ((xAxis[0] * position[0]) + (xAxis[1] * position[1]) + (xAxis[2] * position[2])) * -1.0f; 

// -dot(yaxis, eye) 
result2 = ((yAxis[0] * position[0]) + (yAxis[1] * position[1]) + (yAxis[2] * position[2])) * -1.0f; 

// -dot(zaxis, eye) 
result3 = ((zAxis[0] * position[0]) + (zAxis[1] * position[1]) + (zAxis[2] * position[2])) * -1.0f; 

// Set the computed values in the view matrix. 
matView.SetValore(0, 0, xAxis[0]); 
matView.SetValore(0, 1, yAxis[0]); 
matView.SetValore(0, 2, zAxis[0]); 
matView.SetValore(0, 3, 0.0f); 

matView.SetValore(1, 0, xAxis[1]); 
matView.SetValore(1, 1, yAxis[1]); 
matView.SetValore(1, 2, zAxis[1]); 
matView.SetValore(1, 3, 0.0f); 

matView.SetValore(2, 0, xAxis[2]); 
matView.SetValore(2, 1, yAxis[2]); 
matView.SetValore(2, 2, zAxis[2]); 
matView.SetValore(2, 3, 0.0f); 

matView.SetValore(3, 0, result1); 
matView.SetValore(3, 1, result2); 
matView.SetValore(3, 2, result3); 
matView.SetValore(3, 3, 1.0f);

結果我從OpenGL和從SVG輸出得到有很大的不同，但在兩天內我不能拿出一個解決方案。

這是OpenGL的輸出 enter image description here