Mail Archives: djgpp/1997/07/20/22:57:08
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DJ Delorie wrote:
>
> Remember that VGA memory is so slow it often doesn't matter how fast
> your code is. Try copying to/from DOS memory and see how fast it is.
Do you mean(in pseudo code)
for y
for x
put pix
get pix
Well, I now tested as put pix & then get pix in buff[200][320]. The put
pix timings & get pix timings as seperate timings but I get the exact
same fps rate(24.98 GFPS-get frames per sec). I think I'll try the
pseudo code above next & see if there is a difference though I doubt
there will be. I have a Q's though before I give you my new code, I've
heard about descriptors & would to know a few things about it. Can I
full source on how to do it correct(my hack off the FAQ didn't seem to
work)? Is it "faster" & safer?
Thanx for your input DJ.
Here's my code.
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#include <sys/farptr.h>
#include <sys/nearptr.h>
#include <dpmi.h>
#include <go32.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
// The includes are from my original file - circle/box/line snipped out
// I owe a big thanx to Sinan for my receipt of some actually working VGA
// code. THAAAAAAAAAAAAAAAANNNNNNNNXXXXXXXXXXXXXXXXXXX!!!!!!!!!!!!! :]
enum GR_MODE{GR_INVALID=-1, GR_TEXT=0x03, GR_VGA=0x13};
enum GR_MODE Set_GR_Mode(enum GR_MODE mode)
{
__dpmi_regs r;
memset(&r, 0, sizeof(r));
r.x.ax=mode;
return(__dpmi_int(0x10,&r) ? GR_INVALID:mode);
}
// ************************************************************************
void Put_Pix_Far(int x, int y, char c)
{
_farpokeb(_dos_ds, 0xA0000+(y<<8)+(y<<6)+x,c);
return;
}
// ************************************************************************
char Get_Pix_Far(int x, int y)
{
return _farpeekb(_dos_ds, 0xA0000+(y<<8)+(y<<6)+x);
}
// ************************************************************************
void Put_Pix_Near(int x, int y, char c)
{
char *v_m=(char *)(0xA0000+__djgpp_conventional_base);
v_m[(y<<8)+(y<<6)+x] = c;
}
// ************************************************************************
char Get_Pix_Near(int x, int y)
{
char *v_m=(char *)(0xA0000+__djgpp_conventional_base);
return v_m[(y<<8)+(y<<6)+x];
}
// ************************************************************************
int main(void)
{
int x, y, co;
uclock_t st1, st2, et1, et2;
char vid_mem_capture_buff[200][320];
if(GR_INVALID==Set_GR_Mode(GR_VGA))
{
printf("Error setting mode 13h\n");
exit(8);
}
// Beginning of FAR PTR SPEED TEST
st1=uclock();
for(co=0; co<7680; co++)
for(y=0; y<200; y++)
for(x=0; x<320; x++)
Put_Pix_Far(x,y,co % 256);
et1=uclock();
// Ending of FAR PTR SPEED TEST
printf("Done w/FAR PTR set_pix test\nHit ENTER to start NEAR PTR"
" set_pix TEST\n");
getchar();
// Beginning of NEAR PTR SPEED TEST
if(__djgpp_nearptr_enable())
{
st2=uclock();
for(co=0; co<7680; co++)
for(y=0; y<200; y++)
for(x=0; x<320; x++)
Put_Pix_Near(x,y,co % 256);
et2=uclock();
};
__djgpp_nearptr_disable();
// Ending of NEAR PTR SPEED TEST
Set_GR_Mode(GR_TEXT);
// Show the results
printf("On my Pentium 120, 16MB RAM, Trident ET6???? w/1MB, while using"
" RHIDE 1.3, GCC\n2.7 w/-O9 & -m386(-m486 I get the same results), I get"
" 24.98 fps for both test.\nIs this unusual?\n\nYour results:\n");
// FAR PTR results
printf("FPS for FAR PTR set_pix = %3.2f\n",
(float)7680/((float)((et1-st1)/UCLOCKS_PER_SEC)));
// NEAR PTR results
printf("FPS for NEAR PTR set_pix= %3.2f\n",
(float)7680/((float)((et2-st2)/UCLOCKS_PER_SEC)));
printf("\n\nHit ENTER to start Get_Pix speed test\n");
getchar(); */
// GET PIX TESTS
if(GR_INVALID==Set_GR_Mode(GR_VGA))
{
printf("Error setting mode 13h\n");
exit(8);
}
// Beginning of FAR PTR SPEED TEST
st1=uclock();
for(co=0; co<7680;co++)
for(y=0; y<200; y++)
for(x=0; x<320; x++)
vid_mem_capture_buff[y][x]=Get_Pix_Far(x,y);
et1=uclock();
// Ending of FAR PTR SPEED TEST
printf("Done w/FAR PTR get_pix test\nHit ENTER to start NEAR PTR"
" set_pix TEST\n");
getchar();
for(co=0;co<25;co++) printf("\n");
// Beginning of NEAR PTR SPEED TEST
if(__djgpp_nearptr_enable())
{
st2=uclock();
for(co=0; co<7680; co++)
for(y=0; y<200; y++)
for(x=0; x<320; x++)
vid_mem_capture_buff[y][x]=Get_Pix_Near(x,y);
et2=uclock();
};
__djgpp_nearptr_disable();
// Ending of NEAR PTR SPEED TEST
Set_GR_Mode(GR_TEXT);
// Show the results
printf("On my Pentium 120, 16MB RAM, Trident ET6???? w/1MB, while using"
" RHIDE 1.3, GCC\n2.7 w/-O9 & -m386(-m486 I get the same results), I get"
" 90.35 fps for both test.\nIs this unusual?\n\nYour results:\n");
// FAR PTR results
printf("FPS for FAR PTR get_pix = %3.2f\n",
(float)7680/((float)((et1-st1)/UCLOCKS_PER_SEC)));
// NEAR PTR results
printf("FPS for NEAR PTR get_pix= %3.2f\n",
(float)7680/((float)((et2-st2)/UCLOCKS_PER_SEC)));
getchar();
return 0;
}
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