Source/SR_Triangle.c

/******************************************************************************
 **                                                                          **
 **     Module:     SR_Triangle.c                                            **
 **                                                                          **
 **                                                                          **
 **     Purpose:    Sample Renderer triangle routines                        **
 **                                                                          **
 **                                                                          **
 **                                                                          **
 **     Copyright (C) 1996 Apple Computer, Inc.  All rights reserved.        **
 **                                                                          **
 **                                                                          **
 *****************************************************************************/
#include <assert.h>
 
#include "QD3D.h"
 
#include "SR.h"
#include "SR_Math.h"
 
 
/*===========================================================================*\
 *
 *  Routine:    SR_Geometry_Triangle()
 *
 *  Comments:   
 *
\*===========================================================================*/
 
TQ3Status SR_Geometry_Triangle(
    TQ3ViewObject           view, 
    TSRPrivate              *srPrivate,
    TQ3GeometryObject       triangle, 
    const TQ3TriangleData   *triangleData)
{
    unsigned long           numVertices;
    TQ3Boolean              highlightState;
    TQ3XClipMaskState       clipMaskState;
    TQ3ColorRGB             color;
    TQ3Vector3D             normal;
    
    UNUSED(triangle);
 
    assert(view         != NULL);
    assert(srPrivate    != NULL);
    assert(triangleData != NULL);
 
    /*
     *  Call the application's idle progress method, via the view.  If
     *  the app's method returns kQ3Failure, then we don't go on.
     */
    if (SR_IdleProgress(view, srPrivate) == kQ3Failure) {
        return (kQ3Success);
    }
 
    if (srPrivate->drawRegion == NULL) {
        return (kQ3Success);
    }
    
    /*
     *  Find out if we're clipped out or not. No reason to go any
     *  further if the region is obscured or entirely off-screen. 
     */
    Q3XDrawRegion_GetClipFlags(srPrivate->drawRegion, &clipMaskState);
    if (clipMaskState == kQ3XClipMaskNotExposed) {
        return (kQ3Success);
    }
 
    /*
     *  Lazy-evaluate the various transforms for the pipeline
     */
    if (SR_UpdatePipeline(srPrivate) == kQ3Failure) {
        return (kQ3Failure);
    }
 
    /*
     *  Amazingly enough, triangles have three vertices :-)
     */
    numVertices = 3;
                
    /*
     *  Highlight state and  color are from the view, unless
     *  overridden by the triangleAttributeSet
     */
    highlightState  = srPrivate->viewHighlightState;
    color           = srPrivate->viewDiffuseColor;
 
    /*
     *  Check if we have a triangle attribute set.
     *  If so, then see if we can get a color and highlight state
     *  out of it. 
     */
    if (triangleData->triangleAttributeSet != NULL) {
        TQ3XAttributeMask   attributeMask;
        
        attributeMask = Q3XAttributeSet_GetMask(triangleData->triangleAttributeSet);
        
        if (attributeMask & kQ3XAttributeMaskDiffuseColor) {
            Q3AttributeSet_Get(
                triangleData->triangleAttributeSet,
                kQ3AttributeTypeDiffuseColor,
                &color);
        }
 
        if (attributeMask & kQ3XAttributeMaskHighlightState) {
            Q3AttributeSet_Get(
                triangleData->triangleAttributeSet, 
                kQ3AttributeTypeHighlightState, 
                &highlightState);
        }
    }
 
    /*
     *  If we're highlighting, then see if we can get a highlight color
     *  out of the view's attribute set. Use that as the color, if it's there.
     */
    if ((highlightState == kQ3True) &&
        (srPrivate->viewHighlightAttributeSet != NULL)) {
        TQ3XAttributeMask   attributeMask;
        
        attributeMask = Q3XAttributeSet_GetMask(
                            srPrivate->viewHighlightAttributeSet);
                            
        if (attributeMask & kQ3XAttributeMaskDiffuseColor) {
            Q3AttributeSet_Get( 
                srPrivate->viewHighlightAttributeSet, 
                kQ3AttributeTypeDiffuseColor, 
                &color);
        }
    }
    
    /*
     *  Get the normal for the triangle
     */
    SRTriangle_GetNormal(
        (TQ3TriangleData *)triangleData, 
        &normal);
    
    switch (srPrivate->viewFillStyle) {
        case kQ3FillStyleFilled:    
        case kQ3FillStyleEdges: {
            if (SR_LinePipe(
                    srPrivate, 
                    (TQ3Point3D *)triangleData->vertices, 
                    numVertices, 
                    sizeof(TQ3Vertex3D),
                    &color,
                    &normal,
                    DO_POLYGON) == kQ3Failure) {
                return (kQ3Failure);
            }
            break;
        }
        case kQ3FillStylePoints: {
            if (SR_PointPipe(
                    srPrivate, 
                    (TQ3Point3D *)triangleData->vertices, 
                    numVertices, 
                    sizeof(TQ3Vertex3D),
                    &color,
                    &normal,
                    DO_POLYGON) == kQ3Failure) {
                return (kQ3Failure);
            }
            break;
        }
        default: {
            return (kQ3Failure);
            break;
        }
    }
 
    return (kQ3Success);
}


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