diff options
Diffstat (limited to 'src/particle.zig')
| -rw-r--r-- | src/particle.zig | 86 |
1 files changed, 51 insertions, 35 deletions
diff --git a/src/particle.zig b/src/particle.zig index 5c97ee5..70261b8 100644 --- a/src/particle.zig +++ b/src/particle.zig @@ -2,6 +2,13 @@ const cfg = @import("config.zig"); const std = @import("std"); const rl = @import("raylib"); +pub const particle = struct { + colorId: u32, + x: i32, + y: i32, + xvel: f32, + yvel: f32, +}; /// Initialize a MultiArrayList of size amnt with particles created by createParticle pub fn initParticles(allocator: std.mem.Allocator, amnt: u32) !std.MultiArrayList(particle) { var particles = std.MultiArrayList(particle){}; @@ -13,38 +20,46 @@ pub fn initParticles(allocator: std.mem.Allocator, amnt: u32) !std.MultiArrayLis } /// Applies forces from the ruleset to each particle -pub fn updateVelocities(particles: std.MultiArrayList(particle), rules: [cfg.colorAmnt][cfg.colorAmnt]f32) void { +pub fn updateVelocities( + particles: *std.MultiArrayList(particle), + threadidx: u64, +) void { + const rules = cfg.rules; const colorList = particles.items(.colorId); var xvel = particles.items(.xvel); var yvel = particles.items(.yvel); - for (particles.items(.x), particles.items(.y), 0..) |x, y, i| { + var i: usize = threadidx; + while (i <= particles.len) : (i += cfg.numThreads) { + const p = particles.get(i); var forceX: f32 = 0.0; var forceY: f32 = 0.0; - for (particles.items(.x), particles.items(.y), 0..) |x2, y2, j| { + var j: usize = threadidx; + while (j <= particles.len) : (j += 1) { + const p2 = particles.get(j); if (i == j) continue; - var check2x = x - cfg.screenWidth; - var check2y = y - cfg.screenWidth; - if (x < cfg.screenWidth / 2) check2x = x + cfg.screenWidth; - if (y < cfg.screenHeight / 2) check2y = y + cfg.screenHeight; + var check2x = p.x - rl.getScreenWidth(); + var check2y = p.y - rl.getScreenHeight(); + if (p.x < @divExact(rl.getScreenWidth(), 2)) check2x = p.x + rl.getScreenWidth(); + if (p.y < @divExact(rl.getScreenHeight(), 2)) check2y = p.y + rl.getScreenHeight(); - var rx: f32 = @floatFromInt(x - x2); - var ry: f32 = @floatFromInt(y - y2); - const check2rx: f32 = @floatFromInt(check2x - x2); - const check2ry: f32 = @floatFromInt(check2y - y2); + var distance_x: f32 = @floatFromInt(p.x - p2.x); + var distance_y: f32 = @floatFromInt(p.y - p2.y); + const check2rx: f32 = @floatFromInt(check2x - p2.x); + const check2ry: f32 = @floatFromInt(check2y - p2.y); - if (@abs(rx) > @abs(check2rx)) rx = check2rx; - if (@abs(ry) > @abs(check2ry)) ry = check2ry; + if (@abs(distance_x) > @abs(check2rx)) distance_x = check2rx; + if (@abs(distance_y) > @abs(check2ry)) distance_y = check2ry; - if (rx > cfg.radius or ry > cfg.radius) continue; + if (distance_x > cfg.radius or distance_y > cfg.radius) continue; - var r = @sqrt(rx * rx + ry * ry); + var distance = @sqrt(distance_x * distance_x + distance_y * distance_y); - if (r == 0) r = 0.0001; - if (r > 0 and r < cfg.radius) { - const f = force(r, rules[colorList[i]][colorList[j]]); - forceX = forceX + rx / r * f; - forceY = forceY + ry / r * f; + if (distance == 0) distance = 0.0001; + if (distance > 0 and distance < cfg.radius) { + const f = -force(distance, rules[colorList[i]][colorList[j]]); + forceX += (distance_x / distance) * f; + forceY += (distance_y / distance) * f; } } @@ -58,11 +73,11 @@ pub fn updateVelocities(particles: std.MultiArrayList(particle), rules: [cfg.col /// Applies the particles velocity and updates position pub fn updatePosition(particles: std.MultiArrayList(particle)) void { - for (particles.items(.y), particles.items(.yvel)) |*y, yvel| - y.* = @mod(@as(i32, @intFromFloat(@round((@as(f32, @floatFromInt(y.*)) + yvel)))), cfg.screenHeight); + for (particles.items(.y), particles.items(.yvel)) |*y, yvel| // (y + yvel) % screenHeight + y.* = @mod(@as(i32, @intFromFloat(@round((@as(f32, @floatFromInt(y.*)) + yvel)))), rl.getScreenHeight()); - for (particles.items(.x), particles.items(.xvel)) |*x, xvel| - x.* = @mod(@as(i32, @intFromFloat(@round((@as(f32, @floatFromInt(x.*)) + xvel)))), cfg.screenWidth); + for (particles.items(.x), particles.items(.xvel)) |*x, xvel| // (x + xvel) % screenWidth + x.* = @mod(@as(i32, @intFromFloat(@round((@as(f32, @floatFromInt(x.*)) + xvel)))), rl.getScreenWidth()); } /// Draw the particles onto the screen using raylib @@ -71,19 +86,11 @@ pub fn draw(particles: std.MultiArrayList(particle)) void { rl.drawRectangle(x.*, y.*, 5, 5, cfg.colors[colorId]); } -const particle = struct { - colorId: u32, - x: i32, - y: i32, - xvel: f32, - yvel: f32, -}; - fn force(distance: f32, attraction: f32) f32 { const beta = cfg.minDistance / cfg.radius; const r: f32 = distance / cfg.radius; if (r < beta) - return -(r / beta - 1.0); + return ((beta - r) / (beta - 1.0)); if (beta <= r and r < 1) return attraction * (1 - @abs(2.0 * r - 1.0 - beta) / (1.0 - beta)); return 0; @@ -92,8 +99,8 @@ fn force(distance: f32, attraction: f32) f32 { pub fn createParticle() particle { const seed = @as(u64, @truncate(@as(u128, @bitCast(std.time.nanoTimestamp())))); var prng = std.rand.DefaultPrng.init(seed); - const x = prng.random().uintLessThan(u32, cfg.screenWidth); - const y = prng.random().uintLessThan(u32, cfg.screenHeight); + const x = prng.random().uintLessThan(u32, @intCast(rl.getScreenWidth())); + const y = prng.random().uintLessThan(u32, @intCast(rl.getScreenHeight())); const color = prng.random().uintLessThan(u32, cfg.colorAmnt); return particle{ .colorId = color, @@ -105,3 +112,12 @@ pub fn createParticle() particle { } //TODO: Create tests +test "Force values" { + const expect = std.testing.expect; + cfg.radius = 50; + cfg.minDistance = 20; + const belowMin = force(5.0, 0.5); + const aboveMin = force(25.0, 0.5); + try expect(aboveMin > 0); + try expect(belowMin < 0); +} |