restructure to have en emitter

src/main.zig

@@ -38,7 +38,7 @@ const Particle = struct {
     velocity : pr.Vec = .{.a = .{.x=0,.y=0,.z=0}},
     acceleration : pr.Vec = .{.a = .{.x=0,.y=0,.z=0}},
     lifespan : u8 = 0,
-    spawm : u8 = 1,
+    show : u8 = 0,
     pub fn new(self:Self) void {
         _ = self;
     }
@@ -53,27 +53,93 @@ const Particle = struct {
 
         if (self.lifespan > 0) {
             self.lifespan -= 1;
-        } else 
+        } 
+        else
         {
-            const xrnr = randMinMaxFloat(-1,1);
+            self.show = 0;
-            const yrnr = randMinMaxFloat(-0.5,0.5);
-
-            self.lifespan = rand.intRangeAtMost(u8,75,255);
-            self.acceleration.a.x = xrnr;
-            self.acceleration.a.y = yrnr;
-            self.position.a.x = @floatFromInt(rl.getMouseX()-screenWidth/2);
-            self.position.a.y = @floatFromInt(rl.getMouseY()-screenHeight/2);
-            self.velocity.a.x = 0;
-            self.velocity.a.y = -20;
-            self.position.a.color.r = rand.intRangeAtMost(u8,0,30);
-            self.position.a.color.g = rand.intRangeAtMost(u8,0,255);
-            self.position.a.color.b = rand.intRangeAtMost(u8,0,255);
         }
     }
+    pub fn spawn(self:*Self) void
+    {
+        const xrnr = randMinMaxFloat(-1,1);
+        const yrnr = randMinMaxFloat(-0.5,0.5);
+
+        self.lifespan = rand.intRangeAtMost(u8,75,255);
+        self.acceleration.a.x = xrnr;
+        self.acceleration.a.y = yrnr;
+        self.position.a.x = @floatFromInt(rl.getMouseX()-screenWidth/2);
+        self.position.a.y = @floatFromInt(rl.getMouseY()-screenHeight/2);
+        self.velocity.a.x = 0;
+        self.velocity.a.y = -20;
+        self.position.a.color.r = rand.intRangeAtMost(u8,0,30);
+        self.position.a.color.g = rand.intRangeAtMost(u8,0,255);
+        self.position.a.color.b = rand.intRangeAtMost(u8,0,255);
+        self.show = 1;
+    }
     pub fn applyGravity(self : *Self,val : f32) void {
         self.velocity.a.y += val;
     }
 };
+
+const Emitter = struct
+{
+
+    particleCount : u32 = 0,
+    particles : []Particle = undefined,
+
+    pub fn init(self:*Emitter) !void
+    {
+        var  xrnr = randMinMaxFloat(-1,1);
+        var yrnr = randMinMaxFloat(-0.5,0.5);
+        self.particles = try allocator.alloc(Particle,500000);
+        for (self.particles) |*p| {
+            xrnr = randMinMaxFloat(0,2);
+            yrnr = randMinMaxFloat(0,2);
+            p.* = Particle{.velocity = .{.a = .{.x = 1,.y = -3}},.acceleration = .{.a = .{.x=xrnr,.y=yrnr}}};
+        }
+    }
+    pub fn emit(self:*Emitter,count : u32) void
+    {
+        var i : u32 = 0;
+        for(self.particles) |*p|
+        {
+            if(p.show == 0)
+            {   
+                i+=1;
+                p.spawn();
+            }
+            if(i >= count)
+            {
+                break;
+            }
+        }
+    }
+    pub fn update(self:*Emitter) void
+    {
+        var posx : i32 = 0;
+        var posy : i32 = 0;
+
+
+        for (self.particles) |*p| {
+            if(p.show == 1)
+            {
+                p.update();
+                p.applyGravity(2);
+                if(p.position.a.x >= -(screenWidth/2)){
+                    posx = @intFromFloat(screenWidth / 2 + p.position.a.x);
+                } else {
+                    posx  = 0;
+                }
+                if(p.position.a.y >= -(screenHeight/2)){
+                    posy = @intFromFloat(screenHeight / 2 + p.position.a.y);
+                } else {
+                    posy = 0;
+                }
+                    rl.drawRectangle(posx,posy,2,2,rl.Color{.r=p.position.a.color.r,.g=p.position.a.color.g,.b=p.position.a.color.b,.a=255});
+            }
+        }
+    }
+};
 fn ItoF(x:i32) f32
 {
     return @as(f32,@floatFromInt(x));
@@ -84,7 +150,7 @@ pub fn main() anyerror!void {
     //--------------------------------------------------------------------------------------
 
     const rect2 = rl.Rectangle{ .x = @as(f32, @floatFromInt(10)), .y = @as(f32, @floatFromInt(10)), .width = @as(f32, @floatFromInt(300)), .height = @as(f32, @floatFromInt(100)) };
-    const rect3 = rl.Rectangle{ .x = @as(f32, @floatFromInt(200)), .y = @as(f32, @floatFromInt(150)), .width = @as(f32, @floatFromInt(600)), .height = @as(f32, @floatFromInt(10)) };
+    const rect3 = rl.Rectangle{ .x = @as(f32, @floatFromInt(10)), .y = @as(f32, @floatFromInt(150)), .width = @as(f32, @floatFromInt(600)), .height = @as(f32, @floatFromInt(10)) };
     var msg_res : i32=-1;
     var state : i32=-1;
     
@@ -92,19 +158,11 @@ pub fn main() anyerror!void {
     try std.posix.getrandom(std.mem.asBytes(&seed));
 
     prng = std.rand.DefaultPrng.init(seed);
-    var xrnr : f32 = 0;
-    var yrnr : f32 = 0;
 
-    var posx : i32 = 0;
-    var posy : i32 = 0;
     var value : f32 = 0;
 
-    const p1 = try allocator.alloc(Particle,500000);
+    var emitter = Emitter{};
-    for (p1) |*p| {
+    try emitter.init();
-        xrnr = rand.float(f32);
-        yrnr = rand.float(f32);
-        p.* = Particle{.velocity = .{.a = .{.x = 1,.y = -3}},.acceleration = .{.a = .{.x=xrnr,.y=yrnr}}};
-    }
 
     //const img : rl.Texture = rl.loadTexture("img.png");
 
@@ -139,30 +197,14 @@ pub fn main() anyerror!void {
                     else =>{},
             }
         }
-        _ = rg.guiSlider(rect3,"0","500000",&value,ItoF(0),ItoF(500000));
+        _ = rg.guiSlider(rect3,"0","5000",&value,ItoF(0),ItoF(5000));
-        for (0..,p1) |i,*p| {
+
-            if(i<@as(usize,@intFromFloat(value)))
+        if(rl.isMouseButtonDown(rl.MouseButton.mouse_button_left))
-            {
+        {
-                if(rl.isMouseButtonPressed(rl.MouseButton.mouse_button_left))
+            emitter.emit(@as(u32,@intFromFloat(value)));
-                {
-                    p.spawm = 1;
-                }
-                    p.update();
-                    p.applyGravity(2);
-                    if(p.position.a.x >= -(screenWidth/2)){
-                        posx = @intFromFloat(screenWidth / 2 + p.position.a.x);
-                    } else {
-                        posx  = 0;
-                    }
-                    if(p.position.a.y >= -(screenHeight/2)){
-                        posy = @intFromFloat(screenHeight / 2 + p.position.a.y);
-                    } else {
-                        posy = 0;
-                    }
-                        rl.drawRectangle(posx,posy,2,2,rl.Color{.r=p.position.a.color.r,.g=p.position.a.color.g,.b=p.position.a.color.b,.a=255});
-            }
         }
 
+        emitter.update();
 
     }
 }