Coordinate Systems - Essentials of Interactive Computer Graphics - page 245

void CGrfxWindowD3D::OnPaint()

Source file.
GrfxWindowD3D.cpp file in
the GrfxWindow folder of
the D3D _ ViewTransform0
project.

Step 1: select graphics hardware render buffer.
.
Step 2: initialize selected hardware and set the coordinate system parameters.
.
// Initialize D3D matrix processors setting all three
// matrix processors to identity matrix
m _ pD3DDevice->SetTransform(D3DTS _ WORLD, &identity);
m _ pD3DDevice->SetTransform(D3DTS _ VIEW, &identity);
m _ pD3DDevice->SetTransform(D3DTS _ PROJECTION, &identity);

D3DXMATRIX world2ndc ; // Coordinate Transformation operator
D3DXVECTOR3 scale(2.0f/width, 2.0f/height, 1.0f); // Parameters for the operator
D3DXVECTOR3 translate(-1.0f, -1.0f, 0.0); //

// compute the coordinate transformation operator
D3DXMatrixTransformation(& world2ndc , scale, translate);
// Load the operator into the D3D VIEW matrix
m _ pD3DDevice->SetTransform(D3DTS _ VIEW, & world2ndc );

Step 3: clear drawing buffer and draw two squares.
.
v[0].m _ point = D3DXVECTOR3 (160,122,0);
v[1].m _ point = D3DXVECTOR3 ( 80,122,0);
.
m _ pD3DDevice->DrawPrimitiveUP(D3DPT _ TRIANGLEFAN, 2, (CONST void * )v,

... );

.

Listing 10.1. CGrfxWndD3D:: OnPaint() (Tutorial 10.1)

WC NDC

W H

T(-1,-1)

(W,H)

S( , )

(1,1)

(2,2) 2

H (0,0)

(0,0)

2

(0,0)

W

(-1,-1)

Figure 10.2. The operations of w2n .