From: Erik Max Francis <max AT alcyone DOT com>
Newsgroups: comp.os.msdos.djgpp,comp.lang.c
Subject: Re: Functions in struct's... possible?  How?
Date: Sat, 06 Sep 1997 22:34:42 -0700
Organization: Alcyone Systems
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Message-ID: <34123CF2.455FF641@alcyone.com>
References: <33FCDA5C DOT 2353659F AT execulink DOT com> <5tippg$ci7$2 AT news DOT sendit DOT nodak DOT edu> <3402F5FD DOT 27818183 AT alcyone DOT com> <5u0s9d$70v$3 AT route1 DOT mdrf DOT france3 DOT fr>
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To: djgpp AT delorie DOT com
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Boyd Roberts wrote:

> Maybe not the solution, but definitely the beginning.

Nonsense.  As a software engineer, I've seen people write C++ code that
is far worse than any C code they would have written.

Getting an object oriented language is not the answer.  Understanding
good coding style, object oriented or not, is the answer.

-- 
          Erik Max Francis, &tSftDotIotE / mailto:max AT alcyone DOT com
                        Alcyone Systems / http://www.alcyone.com/max/
   San Jose, California, United States / icbm://37.20.07n/121.53.38w
                                      \
                  "War is like love; / it always finds a way."
                                    / Bertolt Brecht
/////////////////////////////////////////////////////
/////////////////////////////////////////////////////////

void scanline(BITMAP *frame,int w,int h,float x1,float x2,float
z1,float z2,int y,float u1,float u2,float v1,float v2,byte *tex,byte
pcor)
{
w--;//include the zero
h--;
int cor=0;
int x,u,v,width;
float du,dv,dz;


width=(int)(x2-x1);

if(width>0){
     du=(u2-u1)/width;//interpolants
     dv=(v2-v1)/width;
     dz=(z2-z1)/width;
     //draw the line

for(x=(int)x1;x<(int)x2;x++)
     {

     if(x<=w&&x>=0&&y<=h&&y>=0)
     {
      u=(int)(u1/z1);
      v=(int)(v1/z1);
      _putpixel(frame,x,y,tex[(v*128)+u]);
      }//end if


      u1+=du;
      v1+=dv;
      z1+=dz;
       }//end for
      }//end if
}

/////////////////////////////////////////////////////

void render(int w,int h,BITMAP *frame, BITMAP *dest ,FACE a,byte
col,byte *tex,byte pcor)
{
int  y;
char top,side_a,side_b,tmp;          //index to face vertices
float height_a,height_b,height_c;  //tri's side heights

float dx_a,dz_a,du_a,dv_a,         //tri's side interpolants
    dx_b,dz_b,du_b,dv_b,
    dx_c,dz_c,du_c,dv_c;

float z1,z2,x1,x2,u1,u2,v1,v2; //current position in tex/poly


clear_to_color(frame,col);
top=0;
for(int s=0;s<3;s++)//find top vertice
 if(a.c[s].y<a.c[top].y)top=s;
side_a=top+1;      //set up other indexes
side_b=top-1;
if(side_a>2)side_a=0;
if(side_b<0)side_b=2;
//make sure we draw left to right
if(a.c[side_a].x>a.c[side_b].x){tmp=side_a;side_a=side_b;side_b=tmp;}

   //set up heights
   height_a=a.c[side_a].y-a.c[top].y;
   height_b=a.c[side_b].y-a.c[top].y;
    //setup interpolants

    if(height_a>0.0){
     dx_a=(a.c[side_a].x-a.c[top].x)/height_a;
     dz_a=(a.c[side_a].z-a.c[top].z)/height_a;
     du_a=(a.u[side_a]-a.u[top])/height_a;
     dv_a=(a.v[side_a]-a.v[top])/height_a;
    }

    if(height_b>0.0){
     dx_b=(a.c[side_b].x-a.c[top].x)/height_b;
     dz_b=(a.c[side_b].z-a.c[top].z)/height_b;
     du_b=(a.u[side_b]-a.u[top])/height_b;
     dv_b=(a.v[side_b]-a.v[top])/height_b;
    }

//start at top vert
y =(int)a.c[top].y;
x1=a.c[top].x;
x2=a.c[top].x;
z1=a.c[top].z;
z2=a.c[top].z;
u1=a.u[top];
u2=a.u[top];
v1=a.v[top];
v2=a.v[top];


//start to draw
   while(height_a>0.0&&height_b>0.0)
    {
     scanline(frame,w,h,x1,x2,z1,z2,y,u1,u2,v1,v2,tex,pcor);
     height_a--;
     height_b--;
     y++;
     x1+=dx_a;
     x2+=dx_b;
     z1+=dz_a;
     z2+=dz_b;
     u1+=du_a;
     u2+=du_b;
     v1+=dv_a;
     v2+=dv_b;
    } //end while



//new edge find last vertex and draw rest

if(a.c[side_a].y>a.c[side_b].y)
   height_c=a.c[side_a].y-a.c[side_b].y;
if(height_c>0.0){
     dx_c=(a.c[side_a].x-a.c[side_b].x)/height_c;
     dz_c=(a.c[side_a].z-a.c[side_b].z)/height_c;
     du_c=(a.u[side_a]  -a.u[side_b]  )/height_c;
     dv_c=(a.v[side_a]  -a.v[side_b]  )/height_c;

     x2=a.c[side_b].x;
     u2=a.u[side_b];
     v2=a.v[side_b];
     z2=a.c[side_b].z;

while(height_c>0.0)
     {
     scanline(frame,w,h,x1,x2,z1,z2,y,u1,u2,v1,v2,tex,pcor);
     height_c--;
     y++;
     x1+=dx_a;
     x2+=dx_c;
     z1+=dz_a;
     z2+=dz_c;
     u1+=du_a;
     u2+=du_c;
     v1+=dv_a;
     v2+=dv_c;
     }//end while
     }//end if



if(a.c[side_a].y<a.c[side_b].y)
   height_c=a.c[side_b].y-a.c[side_a].y;
   if(height_c>0.0){
     dx_c=(a.c[side_b].x-a.c[side_a].x)/height_c;
     dz_c=(a.c[side_b].z-a.c[side_a].z)/height_c;
     du_c=(a.u[side_b]  -a.u[side_a]  )/height_c;
     dv_c=(a.v[side_b]  -a.v[side_a]  )/height_c;

     x1=a.c[side_a].x;
     u1=a.u[side_a];
     v1=a.v[side_a];
     z1=a.c[side_a].z;

     while(height_c>0.0)
     {
     scanline(frame,w,h,x1,x2,z1,z2,y,u1,u2,v1,v2,tex,pcor);
     height_c--;
     y++;
     x1+=dx_c;
     x2+=dx_b;
     z1+=dz_c;
     z2+=dz_b;
     u1+=du_c;
     u2+=du_b;
     v1+=dv_c;
     v2+=dv_b;
     }//end while
}//end if

blit(frame,dest,0,0,0,0,w,h);
}//end sub



thank u!


and remember if u have any code ideas, suggestion, think i code like a
girl wht ever just help me out!


Billal C

thevoid AT hotmail DOT com