Making the Applications Interesting - Essentials of Interactive Computer Graphics - page 343

void CModel::DrawModel() { Source file. Model.cpp file

in the Model folder of the
D3D _ SimpleTexture project.

// user has selected texture mapping

if (m _ EnableTexture && (m _ pTexture != NULL))
// Enable graphics API texture mapping
pDevice->SetTextureStageState(... D3DTOP _ SELECTARG1);
// Select a current texture map
pDevice->SetTexture(0, m _ pTexture);
// slider bars transformation setting

A:

m _ xform.SetUpModelStack(draw _ helper);
// either draw the circle

B:

if (dt _ circle==m _ DrawType) DrawUnitCircle( pDevice );
// or draw the square
else DrawUnitSquare( pDevice );
// Switch off texture when done

C:

if (m _ EnableTexture && (m _ pTexture != NULL))
// Disable graphics API texture mapping
pDevice->SetTextureStageState(... D3DTOP _ DISABLE);
// Set curren texture map to NULL
pDevice->SetTexture(0, NULL);

D:

}

Listing 12.11. Drawing with file texture.

allocated versions. At label C, we see the utility function that, given a valid path
to an image file, properly loads the m _ pTexture structure into the D3D pDevice .
Listing 12.11 shows that to draw with the loaded texture, we must enable the
texture-mapping functionality and define how to use the texel values (at label
A). At label B, we set up the WORLD matrix processor to support user-specified
transformations. At label C, either the circle or square will be drawn. At label
D, to ensure the proper rendering state, texture-mapping functionality is switched
off after the primitive is drawn.
This tutorial shows us that we can switch texture mapping on/off at any point
before/after drawing primitives. This means that in our primitive hierarchy, we
can define texture mapping as a per-primitive attribute and control the texturing
of each primitive independently.

UWBGL_D3D_Lib13 Support for File Texture

Change summary. See p. 525
for a summary of changes to
the library.

As pointed out in Section 12.3.5 and demonstrated in Tutorial 12.4, the important
three steps in programming with file texture mapping are as follows.