import gg import gx import runtime import time const pwidth = 800 const pheight = 600 const chunk_height = 2 // the image is recalculated in chunks, each chunk processed in a separate thread const zoom_factor = 1.1 const max_iterations = 255 struct ViewRect { mut: x_min f64 x_max f64 y_min f64 y_max f64 } fn (v &ViewRect) width() f64 { return v.x_max - v.x_min } fn (v &ViewRect) height() f64 { return v.y_max - v.y_min } struct AppState { mut: gg &gg.Context = unsafe { nil } iidx int pixels &u32 = unsafe { vcalloc(pwidth * pheight * sizeof(u32)) } npixels &u32 = unsafe { vcalloc(pwidth * pheight * sizeof(u32)) } // all drawing happens here, results are swapped at the end view ViewRect = ViewRect{-3.0773593290970673, 1.4952456603855397, -2.019938598189011, 2.3106642054225945} scale int = 1 ntasks int = runtime.nr_jobs() } const colors = [gx.black, gx.blue, gx.red, gx.green, gx.yellow, gx.orange, gx.purple, gx.white, gx.indigo, gx.violet, gx.black, gx.blue, gx.orange, gx.yellow, gx.green].map(u32(it.abgr8())) struct MandelChunk { cview ViewRect ymin f64 ymax f64 } fn (mut state AppState) update() { mut chunk_channel := chan MandelChunk{cap: state.ntasks} mut chunk_ready_channel := chan bool{cap: 1000} mut threads := []thread{cap: state.ntasks} defer { chunk_channel.close() threads.wait() } for t in 0 .. state.ntasks { threads << go state.worker(t, chunk_channel, chunk_ready_channel) } // mut oview := ViewRect{} mut sw := time.new_stopwatch() for { sw.restart() cview := state.view if oview == cview { time.sleep(5 * time.millisecond) continue } // schedule chunks, describing the work: mut nchunks := 0 for start := 0; start < pheight; start += chunk_height { chunk_channel <- MandelChunk{ cview: cview ymin: start ymax: start + chunk_height } nchunks++ } // wait for all chunks to be processed: for _ in 0 .. nchunks { _ := <-chunk_ready_channel } // everything is done, swap the buffer pointers state.pixels, state.npixels = state.npixels, state.pixels println('${state.ntasks:2} threads; ${sw.elapsed().milliseconds():3} ms / frame; scale: ${state.scale:4}') oview = cview } } [direct_array_access] fn (mut state AppState) worker(id int, input chan MandelChunk, ready chan bool) { for { chunk := <-input or { break } yscale := chunk.cview.height() / pheight xscale := chunk.cview.width() / pwidth mut x, mut y, mut iter := 0.0, 0.0, 0 mut y0 := chunk.ymin * yscale + chunk.cview.y_min mut x0 := chunk.cview.x_min for y_pixel := chunk.ymin; y_pixel < chunk.ymax && y_pixel < pheight; y_pixel++ { yrow := unsafe { &state.npixels[int(y_pixel * pwidth)] } y0 += yscale x0 = chunk.cview.x_min for x_pixel := 0; x_pixel < pwidth; x_pixel++ { x0 += xscale x, y = x0, y0 for iter = 0; iter < max_iterations; iter++ { x, y = x * x - y * y + x0, 2 * x * y + y0 if x * x + y * y > 4 { break } } unsafe { yrow[x_pixel] = colors[iter & 15] } } } ready <- true } } fn (mut state AppState) draw() { mut istream_image := state.gg.get_cached_image_by_idx(state.iidx) istream_image.update_pixel_data(state.pixels) size := gg.window_size() state.gg.draw_image(0, 0, size.width, size.height, istream_image) } fn (mut state AppState) zoom(zoom_factor f64) { c_x, c_y := (state.view.x_max + state.view.x_min) / 2, (state.view.y_max + state.view.y_min) / 2 d_x, d_y := c_x - state.view.x_min, c_y - state.view.y_min state.view.x_min = c_x - zoom_factor * d_x state.view.x_max = c_x + zoom_factor * d_x state.view.y_min = c_y - zoom_factor * d_y state.view.y_max = c_y + zoom_factor * d_y state.scale += if zoom_factor < 1 { 1 } else { -1 } } fn (mut state AppState) center(s_x f64, s_y f64) { c_x, c_y := (state.view.x_max + state.view.x_min) / 2, (state.view.y_max + state.view.y_min) / 2 d_x, d_y := c_x - state.view.x_min, c_y - state.view.y_min state.view.x_min = s_x - d_x state.view.x_max = s_x + d_x state.view.y_min = s_y - d_y state.view.y_max = s_y + d_y } // gg callbacks: fn graphics_init(mut state AppState) { state.iidx = state.gg.new_streaming_image(pwidth, pheight, 4, pixel_format: .rgba8) } fn graphics_frame(mut state AppState) { state.gg.begin() state.draw() state.gg.end() } fn graphics_click(x f32, y f32, btn gg.MouseButton, mut state AppState) { if btn == .right { size := gg.window_size() m_x := (x / size.width) * state.view.width() + state.view.x_min m_y := (y / size.height) * state.view.height() + state.view.y_min state.center(m_x, m_y) } } fn graphics_move(x f32, y f32, mut state AppState) { if state.gg.mouse_buttons.has(.left) { size := gg.window_size() d_x := (f64(state.gg.mouse_dx) / size.width) * state.view.width() d_y := (f64(state.gg.mouse_dy) / size.height) * state.view.height() state.view.x_min -= d_x state.view.x_max -= d_x state.view.y_min -= d_y state.view.y_max -= d_y } } fn graphics_scroll(e &gg.Event, mut state AppState) { state.zoom(if e.scroll_y < 0 { zoom_factor } else { 1 / zoom_factor }) } fn graphics_keydown(code gg.KeyCode, mod gg.Modifier, mut state AppState) { s_x := state.view.width() / 5 s_y := state.view.height() / 5 // movement mut d_x, mut d_y := 0.0, 0.0 if code == .enter { println('> ViewRect{$state.view.x_min, $state.view.x_max, $state.view.y_min, $state.view.y_max}') } if state.gg.pressed_keys[int(gg.KeyCode.left)] { d_x -= s_x } if state.gg.pressed_keys[int(gg.KeyCode.right)] { d_x += s_x } if state.gg.pressed_keys[int(gg.KeyCode.up)] { d_y -= s_y } if state.gg.pressed_keys[int(gg.KeyCode.down)] { d_y += s_y } state.view.x_min += d_x state.view.x_max += d_x state.view.y_min += d_y state.view.y_max += d_y // zoom in/out if state.gg.pressed_keys[int(gg.KeyCode.left_bracket)] || state.gg.pressed_keys[int(gg.KeyCode.z)] { state.zoom(1 / zoom_factor) return } if state.gg.pressed_keys[int(gg.KeyCode.right_bracket)] || state.gg.pressed_keys[int(gg.KeyCode.x)] { state.zoom(zoom_factor) return } } fn main() { mut state := &AppState{} state.gg = gg.new_context( width: 800 height: 600 create_window: true window_title: 'The Mandelbrot Set' init_fn: graphics_init frame_fn: graphics_frame click_fn: graphics_click move_fn: graphics_move keydown_fn: graphics_keydown scroll_fn: graphics_scroll user_data: state ) go state.update() state.gg.run() }