rpi4-osdev/part12-wgt/examples/wgt03.c
2021-03-10 18:35:08 +00:00

147 lines
3 KiB
C

#include "wgt.h"
// ######## REQUIRED FUNCTIONS ########
unsigned long state0 = 1000;
unsigned long state1 = 2000;
unsigned long rand(void)
{
unsigned long s1 = state0;
unsigned long s0 = state1;
state0 = s0;
s1 ^= s1 << 23;
s1 ^= s1 >> 17;
s1 ^= s0;
s1 ^= s0 >> 26;
state1 = s1;
return state0 + state1;
}
void wait_msec(unsigned int n)
{
register unsigned long f, t, r;
// Get the current counter frequency
asm volatile ("mrs %0, cntfrq_el0" : "=r"(f));
// Read the current counter
asm volatile ("mrs %0, cntpct_el0" : "=r"(t));
// Calculate expire value for counter
t+=((f/1000)*n)/1000;
do{asm volatile ("mrs %0, cntpct_el0" : "=r"(r));}while(r<t);
}
// ######## STUB FUNCTIONS ########
unsigned int kb = 0;
unsigned int kbhit(void) {
kb++;
return kb / 500;
}
void getch(void) {
wait_msec(0x500000);
kb = 0;
}
// ######## WGT EXAMPLES ########
#define TIMERSPEED 60 /* timer_routine is called 60 times per second */
int timer; /* Counts how many times it has been called */
int clearcount; /* Counts the number of screen clears. */
int curx = 0;
int cury = 0;
void debugstr(char *str) {
if (curx + (strlen(str) * 8) >= 1920) {
curx = 0; cury += 8;
}
if (cury + 8 >= 1080) {
cury = 0;
}
wtextcolor(vgapal[15]);
wouttextxy (curx, cury, NULL, str);
curx += (strlen(str) * 8);
}
void debugcrlf(void) {
curx = 0; cury += 8;
}
void debugch(unsigned char b) {
unsigned int n;
int c;
for(c=4;c>=0;c-=4) {
n=(b>>c)&0xF;
n+=n>9?0x37:0x30;
debugstr((char *)&n);
}
debugstr(" ");
}
void debughex(unsigned int d) {
unsigned int n;
int c;
for(c=28;c>=0;c-=4) {
n=(d>>c)&0xF;
n+=n>9?0x37:0x30;
debugstr((char *)&n);
}
debugstr(" ");
}
void timer_routine (void)
{
timer++;
}
void wgt03()
{
vga256 (); /* Initialize WGT system */
debugstr ("WGT Example #3"); debugcrlf(); debugcrlf();
debugstr ("This program will use the wcls routine to clear the screen"); debugcrlf();
debugstr ("using random colors as fast as it can until you press a key."); debugcrlf();
debugstr ("It will then report the highest frame rate possible on your computer."); debugcrlf(); debugcrlf(); debugcrlf();
debugstr ("Press any key to continue."); debugcrlf();
getch ();
clearcount = 0;
timer = 0;
winittimer ();
wstarttimer (timer_routine, TIMERSPEED);
curx = 0;
cury = 0;
while (!kbhit ())
{
wcls(vgapal[rand() % 256]); /* Clear with random color out of 256 */
clearcount++;
}
wstoptimer ();
wdonetimer ();
getch ();
wcls(vgapal[0]);
unsigned int fps = clearcount / (timer / TIMERSPEED);
debughex(fps); debugstr("frames per second"); debugcrlf();
debugstr ("This is the highest frame rate your computer can produce for full screen\n"); debugcrlf();
debugstr ("animation."); debugcrlf();
}
void main()
{
wgt03();
while (1);
}