From f175f0844506ecb20fc3305752e0bbbe049d0f5e Mon Sep 17 00:00:00 2001
From: Joseph Ferano <joseph@ferano.io>
Date: Sun, 25 Aug 2024 10:51:51 +0700
Subject: [PATCH] Adding asteroids

---
 game.odin | 93 ++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 82 insertions(+), 11 deletions(-)

diff --git a/game.odin b/game.odin
index 7a26c74..25f3b56 100644
--- a/game.odin
+++ b/game.odin
@@ -4,6 +4,9 @@ import rl "vendor:raylib"
 import "core:math"
 import "core:fmt"
 
+Vec2 :: [2]f32
+Rect :: [4]f32
+
 SCREEN_WIDTH : i32 = 1280
 SCREEN_HEIGHT : i32 = 720
 
@@ -14,13 +17,27 @@ SHIP_H: f32 = 100 * SCALE
 THRUST_SPEED : f32 = 0.03
 ANGULAR_SPEED : f32 = 2.5
 
-Vec2 :: [2]f32
+BULLET_SPEED : f32 = 0.05
+
+Bullet :: struct {
+    pos: Vec2,
+    vel: Vec2,
+}
+
+Asteroid :: struct {
+    pos: Vec2,
+    vel: Vec2,
+    size: Rect,
+    rot: f32,
+}
 
 GameState :: struct {
+    dt: f32,
     ship_pos: Vec2,
     ship_angle: f32,
     ship_vel: Vec2,
-    dt: f32,
+    bullets:   [dynamic]Bullet,
+    asteroids: [dynamic]Asteroid,
 }
 
 rotate_vec2 :: proc(v : Vec2, angle: f32) -> Vec2 {
@@ -31,25 +48,57 @@ rotate_vec2 :: proc(v : Vec2, angle: f32) -> Vec2 {
 }
 
 get_ship_shape :: proc(s : GameState) -> (Vec2, Vec2, Vec2, Vec2) {
-    v1 := rotate_vec2({ SHIP_H*0.5,   0},          s.ship_angle) + s.ship_pos
-    v2 := rotate_vec2({-SHIP_H*0.5,  -SHIP_W*0.5}, s.ship_angle) + s.ship_pos
-    v3 := rotate_vec2({-SHIP_H*0.5*0.5, 0},        s.ship_angle) + s.ship_pos
-    v4 := rotate_vec2({-SHIP_H*0.5,   SHIP_W*0.5}, s.ship_angle) + s.ship_pos
+    v1 := rl.Vector2Rotate({ SHIP_H*0.5,   0},          s.ship_angle) + s.ship_pos
+    v2 := rl.Vector2Rotate({-SHIP_H*0.5,  -SHIP_W*0.5}, s.ship_angle) + s.ship_pos
+    v3 := rl.Vector2Rotate({-SHIP_H*0.5*0.5, 0},        s.ship_angle) + s.ship_pos
+    v4 := rl.Vector2Rotate({-SHIP_H*0.5,   SHIP_W*0.5}, s.ship_angle) + s.ship_pos
     return v1, v2, v3, v4
 }
 
+swap_n_pop :: proc(bullets: ^[dynamic]Bullet, idx: int) {
+    last := len(bullets) - 1
+    if last == 0 {
+        clear(bullets)
+    } else {
+        bullets[last], bullets[idx] = bullets[idx], bullets[last]
+        pop(bullets)
+    }
+}
+
 main :: proc() {
     rl.SetTraceLogLevel(.ERROR)
     rl.InitWindow(SCREEN_WIDTH, SCREEN_HEIGHT, "Asteroids")
 
-    s := GameState{{0,0}, -math.PI / 2, {0,0}, rl.GetFrameTime()}
+    s := GameState{
+        rl.GetFrameTime(),
+        {0,0},
+        -math.PI / 2,
+        {0,0},
+        make([dynamic]Bullet, 0, 64),
+        make([dynamic]Asteroid, 0, 64),
+    }
     s.ship_pos = {600, 350}
 
     bw := f32(SCREEN_WIDTH)
     bh := f32(SCREEN_HEIGHT)
 
+    bullet_pop_idxs := make([dynamic]int, 0, 64)
+
+    for i := 0; i < 5; i += 1 {
+        asteroid := Asteroid {
+            pos  = {f32(rl.GetRandomValue(0, i32(bw))),-10},
+            vel  = {f32(rl.GetRandomValue(0, i32(bw))), f32(rl.GetRandomValue(0, i32(bw)))},
+            size = {0,0,0,0},
+            rot  = 0,
+        }
+        append(&s.asteroids, asteroid)
+    }
+
     for !rl.WindowShouldClose() {
         s.dt = rl.GetFrameTime()
+
+        v1, v2, v3, v4 := get_ship_shape(s)
+
         if rl.IsKeyDown(.D) {
             s.ship_angle += ANGULAR_SPEED * s.dt
         }
@@ -60,25 +109,47 @@ main :: proc() {
             s.ship_vel.x += math.cos(s.ship_angle) * THRUST_SPEED * s.dt
             s.ship_vel.y += math.sin(s.ship_angle) * THRUST_SPEED * s.dt
         }
+        if rl.IsKeyPressed(.SPACE) {
+            b_vel := Vec2{ math.cos(s.ship_angle) , math.sin(s.ship_angle) } * BULLET_SPEED
+            append(&s.bullets, Bullet{v1,b_vel})
+        }
 
         s.ship_pos += s.ship_vel * (5000 * s.dt)
 
+        for i := 0; i < len(s.bullets); i += 1 {
+            s.bullets[i].pos += s.bullets[i].vel
+        }
 
         if s.ship_pos.x + SHIP_W < 0  { s.ship_pos.x = bw + SHIP_W}
-        if s.ship_pos.x - SHIP_W > bw { s.ship_pos.x = SHIP_W}
-        if s.ship_pos.y +  < 0  { s.ship_pos.y = bh}
-        if s.ship_pos.y > bh { s.ship_pos.y = 0}
+        if s.ship_pos.x - SHIP_W > bw { s.ship_pos.x = -SHIP_W}
+        if s.ship_pos.y + SHIP_H < 0  { s.ship_pos.y = bh + SHIP_H}
+        if s.ship_pos.y - SHIP_H > bh { s.ship_pos.y = -SHIP_H}
 
         rl.BeginDrawing()
         rl.ClearBackground(rl.BLACK)
 
         // Draw ship
-        v1, v2, v3, v4 := get_ship_shape(s)
         rl.DrawLineEx(v1, v2, 1, rl.WHITE)
         rl.DrawLineEx(v2, v3, 1, rl.WHITE)
         rl.DrawLineEx(v3, v4, 1, rl.WHITE)
         rl.DrawLineEx(v4, v1, 1, rl.WHITE)
 
+        for i := 0; i < len(s.bullets); i += 1 {
+            if (   s.bullets[i].pos.x < 0 || s.bullets[i].pos.x > bw
+                || s.bullets[i].pos.y < 0 || s.bullets[i].pos.y > bh) {
+                append(&bullet_pop_idxs, i)
+            }
+            rl.DrawCircleLinesV(s.bullets[i].pos, 5, rl.WHITE)
+        }
+
+        bpi_len := len(bullet_pop_idxs)
+        for i := 0; i < bpi_len; i += 1 {
+            swap_n_pop(&s.bullets, bullet_pop_idxs[i])
+        }
+        if bpi_len > 0 {
+            clear(&bullet_pop_idxs)
+        }
+
         rl.EndDrawing()
     }