Please try out the following code snipet (not very large if you leave the
commented lines away...
You can compile it with gcc -g 3d.c -lm -lvga -o 3d
If you try it out it produces a segmentation fault... (Why???)
If you declare the variable count a little bit further down it doesn't produce
the segmentation fault. After I used ddd to locate the failure it told me
that the variable count is overwritten with strange numbers that are out of
the program memmory.
I'm using gcc 3.2.2 on slackware 9.0
Isn't that strange ???
If you have any Idea what's going on there please let me know
I know you don't want to have code snipets but that was the only way to
reproduce the error. So hope that helps....
Wolfgang Meyerle
----_Snip--------------------------------------
#include <stdio.h>
#include <vga.h>
#include <math.h>
struct point3d
{
double x;
double y;
double z;
};
int main(void)
{
char a[1024];
int i;
int count;
char c;
struct point3d points[4];
struct point3d center;
points[0].x=-412;
points[0].y=-50;
points[0].z=1;
points[1].x=+412;
points[1].y=-50;
points[1].z=1;
points[2].x=-412;
points[2].y=+50;
points[2].z=1;
points[3].x=+412;
points[3].y=+50;
points[3].z=1;
center.x=(1024)/2;
center.y=100+50;
center.z=0.5;
/*
p[4] p[5]
v v
/---------/
p[0] > /_________/| p[1]
| | |
p[6] >| _______ | / p[7]
|/---------/
p[2] ^ p[3]^
*/
// ------------------------------------------
points[4].x=-412;
points[4].y=-50;
points[4].z=0.8;
points[5].x=+412;
points[5].y=-50;
points[5].z=0.8;
points[6].x=-412;
points[6].y=+50;
points[6].z=0.8;
points[7].x=+412;
points[7].y=+50;
points[7].z=0.8;
/*
if (vga_init()) return 1;
if (vga_setmode(G1024x768x256)) return(1);
vga_setcolor(200);
vga_setpalette(200,255,255,255);
*/
do
{
/*
vga_clear();
vga_drawline(center.x +
points[0].x*points[0].z,center.y+points[0].y*points[0].z,center.x+points[1].x*points[1].z,center.y+points[1].y*points[1].z);
vga_drawline(center.x +
points[0].x*points[0].z,center.y+points[0].y*points[0].z,center.x+points[2].x*points[2].z,center.y+points[2].y*points[2].z);
vga_drawline(center.x +
points[1].x*points[1].z,center.y+points[1].y*points[1].z,center.x+points[3].x*points[3].z,center.y+points[3].y*points[3].z);
vga_drawline(center.x +
points[2].x*points[1].z,center.y+points[2].y*points[2].z,center.x+points[3].x*points[3].z,center.y+points[3].y*points[3].z);
// ----------------------------------------------------------
vga_drawline(center.x +
points[0].x*points[0].z,center.y+points[0].y*points[0].z,center.x+points[4].x*points[4].z,center.y+points[4].y*points[4].z);
vga_drawline(center.x +
points[4].x*points[4].z,center.y+points[4].y*points[4].z,center.x+points[5].x*points[5].z,center.y+points[5].y*points[5].z);
vga_drawline(center.x +
points[1].x*points[1].z,center.y+points[1].y*points[1].z,center.x+points[5].x*points[5].z,center.y+points[5].y*points[5].z);
vga_drawline(center.x +
points[2].x*points[2].z,center.y+points[2].y*points[2].z,center.x+points[6].x*points[6].z,center.y+points[6].y*points[6].z);
vga_drawline(center.x +
points[6].x*points[6].z,center.y+points[6].y*points[6].z,center.x+points[7].x*points[7].z,center.y+points[7].y*points[7].z);
vga_drawline(center.x +
points[3].x*points[3].z,center.y+points[3].y*points[3].z,center.x+points[7].x*points[7].z,center.y+points[7].y*points[7].z);
vga_drawline(center.x +
points[6].x*points[6].z,center.y+points[6].y*points[6].z,center.x+points[4].x*points[4].z,center.y+points[4].y*points[4].z);
vga_drawline(center.x +
points[7].x*points[7].z,center.y+points[7].y*points[7].z,center.x+points[5].x*points[5].z,center.y+points[5].y*points[5].z);
*/
for (count=0;count<8;count++)
{
points[count].y=(points[count].y)*cos((double) (M_PI/180));
points[count].z=(points[count].z)*cos((double) (M_PI/180));
}
c=vga_getch();
} while (c!='a');
return 0;
}
--------------------------Snip-----------------
