AmigaExamples/005.copper_vert/copper_gen_vert.c

45 lines
1.2 KiB
C

// http://krazydad.com/tutorials/makecolors.php
#include <stdio.h>
#include <math.h>
int
main(int argc, char** argv)
{
int startLine = 0x2c; // hard coded value from AHRM
int screenHeight = 256;
int endLine = startLine+screenHeight;
int startHpos = 6+8;
int i, c, line;
// These values are set up to be in sync with the vertical bars
float frequencyr = 0.3, frequencyg = 0.3, frequencyb = 0.3;
float phase1 = 0, phase2 = 2, phase3 = 4;
float offset = 0;
float center = 0x7;
float width = 0x7;
int hstep = 16;
for (line = startLine; line < endLine; ++line) {
for (i = 0, c = startHpos; c < 0xdf; c+= hstep, i++) {
unsigned char r = (sin(frequencyr*i + phase1 + offset) * width + center) + 0.5;
unsigned char g = (sin(frequencyg*i + phase2 + offset) * width + center) + 0.5;
unsigned char b = (sin(frequencyb*i + phase3 + offset) * width + center) + 0.5;
if (line == 0 && i == 0) {
} else {
if (line <= 255) {
printf("\tdc.w $%x,$fffe\n\tdc.w COLOR00,$%x%x%x\n",line<<8|c|1, r, g, b);
if (line == 255 && c+hstep >= 0xdf) {
printf(".verticalPositionWrapped:\n");
}
} else {
printf("\tdc.w $%x,$fffe\n\tdc.w COLOR00,$%x%x%x\n", (line-256)<<8|c|1, r, g, b);
}
}
}
}
return 0;
}