55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
// simple.c
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#include <stdio.h>
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#include <stdlib.h>
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#define sqr(x) ((x) * (x))
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typedef struct { double r; double i; } complex;
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void interpret(complex *registers, char const *code) {
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complex *src, *dst;
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double r, i;
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for (; *code; code += 3) {
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dst = ®isters[code[2] - 'a'];
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src = ®isters[code[1] - 'a'];
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switch (*code) {
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case '=':
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dst->r = src->r;
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dst->i = src->i;
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break;
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case '+':
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dst->r += src->r;
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dst->i += src->i;
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break;
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case '*':
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r = dst->r * src->r - dst->i * src->i;
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i = dst->r * src->i + dst->i * src->r;
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dst->r = r;
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dst->i = i;
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break;
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default:
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fprintf(stderr, "undefined instruction %s (ASCII %x)\n", code, *code);
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exit(1);
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}
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}
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}
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int main(int argc, char **argv) {
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complex registers[4];
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int i, x, y;
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char line[1600];
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printf("P5\n%d %d\n%d\n", 1600, 900, 255);
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for (y = 0; y < 900; ++y) {
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for (x = 0; x < 1600; ++x) {
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registers[0].r = 2 * 1.6 * (x / 1600.0 - 0.5);
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registers[0].i = 2 * 0.9 * (y / 900.0 - 0.5);
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for (i = 1; i < 4; ++i) registers[i].r = registers[i].i = 0;
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for (i = 0; i < 256 && sqr(registers[1].r) + sqr(registers[1].i) < 4; ++i)
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interpret(registers, argv[1]);
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line[x] = i;
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}
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fwrite(line, 1, sizeof(line), stdout);
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}
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return 0;
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}
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