55 lines
1.8 KiB
C
55 lines
1.8 KiB
C
#include "twn_game_api.h"
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#include "state.h"
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#include <malloc.h>
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#include <math.h>
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/* Emits `x` and `y` for every intersecting cell */
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/* We snap position to the nearest corner, which means there's no aliasing */
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/* It works great for integer radii */
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#define m_iter_circle_pixels(p_center_x, p_center_y, p_radius) \
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for (float y = (p_center_y + ceilf(p_radius)) - 1; y > (p_center_y - ceilf(p_radius)) - 1; --y) \
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for (float x = p_center_x - ceilf(sqrtf(p_radius * p_radius - (y - p_center_y + (y <= p_center_y)) * (y - p_center_y + (y <= p_center_y)))); x < p_center_x + ceilf(sqrtf(p_radius * p_radius - (y - p_center_y + (y <= p_center_y)) * (y - p_center_y + (y <= p_center_y)))); ++x)
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void game_tick(void) {
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if (ctx.initialization_needed) {
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if (!ctx.udata) {
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ctx.udata = ccalloc(1, sizeof (struct state));
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struct state *state = ctx.udata;
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state->r = 10;
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}
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}
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struct state *state = ctx.udata;
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Vec2 const mouse_snap = {floorf(ctx.mouse_position.x / 8) * 8, floorf(ctx.mouse_position.y / 8) * 8};
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input_action("up", CONTROL_LEFT_MOUSE);
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input_action("down", CONTROL_RIGHT_MOUSE);
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if (input_action_just_pressed("up"))
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state->r += 1;
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if (input_action_just_pressed("down"))
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state->r -= 1;
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float const rs = state->r * state->r;
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float const cr = ceilf(state->r);
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for (float iy = cr - 1; iy > -cr - 1; --iy) {
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float const dx = ceilf(sqrtf(rs - (iy + (iy <= 0)) * (iy + (iy <= 0))));
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for (float ix = -dx; ix < dx; ++ix) {
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draw_box((Rect){mouse_snap.x + ix * 8, mouse_snap.y + iy * 8, 8, 8}, 1, (Color){255, 0, 0, 125});
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}
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}
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draw_circle(mouse_snap, state->r * 8, (Color){125, 125, 125, 125});
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}
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void game_end(void) {
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/* do your deinitialization here */
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struct state *state = ctx.udata;
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free(state);
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}
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