Making the Applications Interesting - Essentials of Interactive Computer Graphics - page 333

disabled, we do not have to worry about blending factors or the blending func-
tion. Notice that the DrawHelper::EnableBlending() function is called dur-
ing SetupDrawAttributes() for each primitive object. in this way, the alpha-
blending functionality is enabled/disabled for each of the UWBGL primitives.
Once again, the support for texture mapping of UWB _ Lib13 will be discussed
in the next section.

class UWB _ Primitive {
.
A: public :
void EnableBlending( bool on ); // Enable/disable primitive blending
bool IsBlendingEnabled() const ; // Query the prmitive's blending state

protected :
bool m _ bBlendingEnabled; // storage of primitive's blending state

B: public :
void SetTextureFileName( const wchar _ t * ); // Set texture file name
const wchar _ t * GetTextureFileName(); // Query texture file name
void EnableTexturing( bool on); // enable/disable primitive file texture mapping
bool IsTexturingEnabled() const ; // Query file texture mapping state

protected :
bool m _ bTexturingEnabled; // storage of primitive's textere mapping state
std::wstring m _ TexFileName; // if enabled, texture file name
.

Source file.
uwbgl _ Primitive3.h/cpp
files in the Common Files/
Primitives

};

subfolder of the

UWBGL _ D3D _ Lib13 project.

void UWB _ Primitive::SetupDrawAttributes(UWB _ DrawHelper& draw _ helper) {
.

draw _ helper.EnableBlending( m _ bBlendingEnabled );
draw _ helper.SetTextureInfo( m _ TexFileName.c _ str() );
draw _ helper.EnableTexture( m _ bTexturingEnabled );
.

C:

Listing 12.6. Modification to Primitive for supporting blending and texturing.