oscar64/samples/rasterirq/textcrawler.c

58 lines
1.5 KiB
C

#include <c64/vic.h>
#include <c64/rasterirq.h>
#include <string.h>
const char * Text =
S"LABORUM RERUM QUO. QUASI IN, SEQUI, TENETUR VOLUPTATEM RERUM "
S"PORRO NON ET MAIORES ALIAS ODIO EST EOS. MAGNAM APERIAM CUM ET "
S"ESSE TEMPORE ITAQUE TEMPORA VOLUPTAS ET IPSAM IPSAM EARUM. ID "
S"SUSCIPIT QUIA RERUM REPREHENDERIT ERROR ET UT. DOLOR ID "
S"CORPORIS, EOS? UNDE VERO ISTE QUIA? EAQUE EAQUE. IN. AUT ID "
S"EXPEDITA ILLUM MOLESTIAS, ";
// Raster interrupt command structure for change to scrolled and back
RIRQCode scroll, bottom;
int main(void)
{
// initialize raster IRQ
rirq_init(true);
// Build switch to scroll line IRQ
rirq_build(&scroll, 1);
// Change control register two with this IRQ
rirq_write(&scroll, 0, &vic.ctrl2, 0);
// Put it onto the scroll line
rirq_set(0, 50 + 24 * 8, &scroll);
// Build the switch to normal IRQ
rirq_build(&bottom, 1);
// re-enable left and right column and reset horizontal scroll
rirq_write(&bottom, 0, &vic.ctrl2, VIC_CTRL2_CSEL);
// place this at the bottom
rirq_set(1, 250, &bottom);
// sort the raster IRQs
rirq_sort();
// start raster IRQ processing
rirq_start();
// Loop through text
int x = 0;
for(;;)
{
// wait for raster reaching bottom of screen
rirq_wait();
// Update raster IRQ for scroll line with new horizontal scroll offset
rirq_data(&scroll, 0, 7 - (x & 7));
// Copy scrolled version of text when switching over char border
if ((x & 7) == 0)
memcpy((char *)0x0400 + 40 * 24, Text + ((x >> 3) & 255), 40);
x++;
}
return 0;
}