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// Few lines of code that demonstrate the basic graphics setup so you can
work
// on doing some simple displays etc
#include
<openxdk.h>
void
xbvDrawCircle( unsigned
int *pdwFramebuffer,
int nSizeStrideInDwords, DWORD dwPixel,
int xC, int
yC, int r )
{
int x=0, y=r, u=1, v=2*r-1, e=0;
while( x < y ){
pdwFramebuffer[(xC+x)+((yC+y)* nSizeStrideInDwords)]=dwPixel;
pdwFramebuffer[(xC+y)+((yC-x)* nSizeStrideInDwords)]=dwPixel;
pdwFramebuffer[(xC-x)+((yC-y)* nSizeStrideInDwords)]=dwPixel;
pdwFramebuffer[(xC-y)+((yC+x)* nSizeStrideInDwords)]=dwPixel;
x++; e += u; u+= 2;
if( v < 2 * e ) { y--; e -= v; v
-= 2; }
if( x > y )
break;
pdwFramebuffer[(xC+y)+((yC+x)* nSizeStrideInDwords)]=dwPixel;
pdwFramebuffer[(xC+x)+((yC-y)* nSizeStrideInDwords)]=dwPixel;
pdwFramebuffer[(xC-y)+((yC-x)* nSizeStrideInDwords)]=dwPixel;
pdwFramebuffer[(xC-x)+((yC+y)* nSizeStrideInDwords)]=dwPixel;
}
}//
end of xbvDrawCircle(..)
volatile
DWORD time;
void
sleep( DWORD ms )
{
DWORD
Target = KeTickCount+ms;
while(1){
time = KeTickCount;
if( time > Target )
break;
}
}//
end of sleep(..)
// Program Entry Point
void
XBoxStartup()
{
//let's init the screen
vga_init_mode(MODE_640x480x32); // Some
possible modes all defined in
// xvga.h
//
MODE_320x240x32
//
MODE_640x240x32
//
MODE_640x480x32 etc...plus many more
float xpos = 640/2;
float ypos = 640/2;
float xdir = 0.5f;
float ydir = 1.0f;
while(1)
{
// A list of all these functions can
be found at the top of xvga.h
// Comment this line out to watch the
ball go crazy! - why is that..well
// we have to wait a bit for it to
finish its blitz to the screen and it slows
// us down...might be better to do
multiple back buffering?
vga_vsync();
// Wait for Vertical Blank
vga_flip();
// Flip
// Comment this line out to see the
effects of the ball going around the screen,
// sort of a trail of itself, you can
also see how far it moves with each movement
vga_clear();
// Clear screen
ScreenInfo s = vga_get_screen_info();
unsigned
int* pix = (unsigned
int*)s.ScreenAddress;
// Draw new circle in a new place
xbvDrawCircle( pix, 640, 0xffffff00, (int)xpos,
(int)ypos, 10 );
xpos += xdir;
ypos += ydir;
int size = 10;
// diameter of our little circle
if( (xpos <= (0+size)) || (xpos
>= (640-size)) ) xdir = -xdir;
if( (ypos <= (0+size)) || (ypos
>= (480-size)) ) ydir = -ydir;
//sleep(50);
}//
End while loop
}//End
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