module main import gg import gx import math const ( win_width = 700 win_height = 800 bg_color = gx.white colour = gx.black ) enum Selection { segs = 0 len } struct App { mut: gg &gg.Context = unsafe { nil } mouse struct { mut: x f32 y f32 } sel Selection segs int = 8 } fn main() { mut app := &App{ gg: 0 } app.gg = gg.new_context( width: win_width height: win_height create_window: true window_title: 'Arcs and Slices' user_data: app bg_color: bg_color frame_fn: on_frame event_fn: on_event ) app.gg.run() } fn on_frame(mut app App) { app.gg.begin() start := math.tau * app.mouse.y / (win_width * app.gg.scale) end := math.tau * app.mouse.x / (win_width * app.gg.scale) segs := if app.sel == .segs { '[$app.segs]' } else { '$app.segs' } app.gg.draw_text_def(10, 10, 'Segments: $segs') app.gg.draw_text_def(250, 10, 'Drawing Angles (radians)') app.gg.draw_text_def(200, 26, 'Start: $start°') app.gg.draw_text_def(350, 26, 'End: $end°') mut x, mut y := 0, -80 y += 150 x = 20 app.gg.draw_text_def(10, y + 40, 'slice') x += 150 app.gg.draw_slice_empty(x, y + 60, 50, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=50 empty') x += 150 app.gg.draw_slice_empty(x, y + 60, 0, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=0 empty') x += 150 app.gg.draw_slice_filled(x, y + 60, 50, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=50 filled') x += 150 app.gg.draw_slice_filled(x, y + 60, 0, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=0 filled') y += 150 x = 20 app.gg.draw_text_def(10, y + 40, 'arc_empty') x += 150 app.gg.draw_arc_empty(x, y + 60, 30, 20, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=[30,50]') x += 150 app.gg.draw_arc_empty(x, y + 60, -10, 60, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=[-10,50]') x += 150 app.gg.draw_arc_empty(x, y + 60, 50, 0, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=[50,50]') x += 150 app.gg.draw_arc_empty(x, y + 60, 0, 0, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=[0,0]') y += 150 x = 20 app.gg.draw_text_def(10, y + 40, 'arc_filled') x += 150 app.gg.draw_arc_filled(x, y + 60, 30, 20, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=[30,50]') x += 150 app.gg.draw_arc_filled(x, y + 60, -10, 60, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=[-10,50]') x += 150 app.gg.draw_arc_filled(x, y + 60, 50, 0, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=[50,50]') x += 150 app.gg.draw_arc_filled(x, y + 60, 0, 0, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=[0,0]') y += 150 x = 20 app.gg.draw_text_def(10, y + 40, 'arc_line') x += 150 app.gg.draw_arc_line(x, y + 60, 50, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=50') x += 150 app.gg.draw_arc_line(x, y + 60, 0, start, end, app.segs, colour) app.gg.draw_text_def(x - 50, y + 120, 'r=0') y += 150 app.gg.draw_text_def(10, y + 20, 'Use arrow keys to increase/decrease number of segments.') app.gg.draw_text_def(10, y + 36, 'Use the mouse to adjust the start/end angles, in radians. Mouse position (0,0) is at the top-left of the window.') app.gg.draw_text_def(10, y + 52, 'Note: because y=0 is at the top of the screen and not the bottom, angle=0 is at the bottom of an arc, not the top!') app.gg.draw_text_def(10, y + 68, 'Compared to a graph, where y=0 is at the bottom, arcs therefore appear y-flipped.') app.gg.end() } fn on_event(e &gg.Event, mut app App) { match e.typ { .key_down { match e.key_code { .escape { app.gg.quit() } .up { app.sel = unsafe { Selection(math.max(0, int(app.sel) - 1)) } } .down { app.sel = unsafe { Selection(math.min(int(Selection.len) - 1, int(app.sel) + 1)) } } .left { match app.sel { .segs { app.segs = math.max(1, app.segs / 2) } else {} } } .right { match app.sel { .segs { app.segs = math.min(64, app.segs * 2) } else {} } } else {} } } .mouse_move { app.mouse.x = e.mouse_x app.mouse.y = e.mouse_y } else {} } }