66 lines
1.2 KiB
C
66 lines
1.2 KiB
C
#include <string.h>
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#include <c64/vic.h>
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#include <c64/memmap.h>
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#include <conio.h>
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// Address of hires buffer and color buffer
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#define Screen ((char *)0xe000)
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#define Color ((char *)0xc800)
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int main(void)
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{
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// Install the IRQ trampoline
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mmap_trampoline();
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// Turn of the kernal ROM
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mmap_set(MMAP_NO_ROM);
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// Switch VIC into hires mode
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vic_setmode(VICM_HIRES, Color, Screen);
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// Clear the screen
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memset(Screen, 0, 8000);
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memset(Color, 0x10, 1000);
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// Loop over all pixels
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int py, px;
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for(py=0; py<200; py++)
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{
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for(px=0; px<320; px++)
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{
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// Value in the complex plane
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float xz = (float)px * (3.5 / 320.0)- 2.5;
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float yz = (float)py * (2.0 / 200.0) - 1.0;
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// Iterate up to 32 times
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float x = 0.0, y = 0.0;
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int i;
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for(i=0; i<32; i++)
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{
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if (x * x + y * y > 4.0) break;
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float xt = x * x - y * y + xz;
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y = 2 * x * y + yz;
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x = xt;
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}
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// Set a pixel if exceeds bound in less than 32 iterations
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if (i < 32)
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Screen[320 * (py >> 3) + (py & 7) + (px & ~7)] |= 0x80 >> (px & 7);
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}
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}
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// Re-enable the kernal
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mmap_set(MMAP_NO_BASIC);
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// Wait for key press
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getch();
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// Restore VIC state
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vic_setmode(VICM_TEXT, (char *)0x0400, (char *)0x1000);
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return 0;
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}
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