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rotating squares

This commit is contained in:
kdx 2023-03-17 11:56:08 +01:00
parent 9b549158ef
commit b6e8281daa
1 changed files with 8 additions and 8 deletions
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16
src/background.c
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@ -3,8 +3,6 @@
#include <math.h>
static long tick = 0;
static const int center_x = DISPLAY_WIDTH / 2;
static const int center_y = DISPLAY_HEIGHT / 2;
static void
rotate(double *x, double *y, double angle)
@ -14,7 +12,7 @@ rotate(double *x, double *y, double angle)
const double ox = *x;
const double oy = *y;
*x = ox * c - ox * s;
*x = ox * c - oy * s;
*y = ox * s + oy * c;
}
@ -25,18 +23,18 @@ draw_square(int size, double angle)
size / 2.0,
size / 2.0,
-size / 2.0,
-size / 2.0
-size / 2.0,
};
double y[4] = {
-size / 2.0,
size / 2.0,
size / 2.0,
-size / 2.0
-size / 2.0,
};
for (int i = 0; i < 4; i++) {
rotate(&x[i], &y[i], angle);
x[i] += center_x;
y[i] += center_y;
x[i] += DISPLAY_WIDTH / 2.0;
y[i] += DISPLAY_HEIGHT / 2.0;
}
LZY_DrawLine(x[0], y[0], x[1], y[1]);
LZY_DrawLine(x[1], y[1], x[2], y[2]);
@ -49,5 +47,7 @@ background_draw(void)
{
tick += 1;
LZY_DrawSetColor(0, 0, 0);
draw_square(64, (double)tick / 10);
draw_square(64 * sin((double)tick / 50), (double)tick / 40);
draw_square(64 * sin((double)tick / 40), (double)tick / 30);
draw_square(64 * sin((double)tick / 30), (double)tick / 20);
}