init, working screens from raylib screens example and basic bullets mechanics

This commit is contained in:
Stefan Stefanov 2024-02-09 19:09:37 +02:00
commit 178cf92f44
3 changed files with 301 additions and 0 deletions

117
game.odin Normal file
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package space_invaders
import "core:c"
import "core:log"
import glm "core:math/linalg/glsl"
import rl "vendor:raylib"
GLOBAL_SPRITE_SCALE :: 2
ALIEN_ROWS :: 5
ALIENS_PER_ROW :: 11
ALIENS :: ALIEN_ROWS * ALIENS_PER_ROW
ALIEN_SIDE_STEP :: 20 * GLOBAL_SPRITE_SCALE
ALIEN_RECT :: glm.ivec2{16 * GLOBAL_SPRITE_SCALE, 16 * GLOBAL_SPRITE_SCALE}
MAX_BULLETS :: 100
BULLET_SPEED :: 240
BULLET_RECT :: glm.ivec2{16 * GLOBAL_SPRITE_SCALE, 16 * GLOBAL_SPRITE_SCALE}
MAX_PLAYER_HEALTH :: 3
PLAYER_SPEED :: 40
PLAYER_RECT :: glm.ivec2{16 * GLOBAL_SPRITE_SCALE, 16 * GLOBAL_SPRITE_SCALE}
Alien :: struct {
alive: bool,
position: glm.vec2,
id: int,
}
Bullet :: struct {
alive: bool,
position: glm.vec2,
}
setup_game :: proc(state: ^GameState) {
using state
player_pos = glm.vec2{f32(screen_width / 2), f32(screen_height - PLAYER_RECT.x)}
// setup the initial positions of the aliens
for row in 0 ..< ALIEN_ROWS {
for alien in 0 ..< ALIENS_PER_ROW {
aliens[(row * ALIENS_PER_ROW) + alien].position = glm.vec2 {
f32((alien + 1) * int(ALIEN_RECT.x + 10)),
f32((row + 1) * int(ALIEN_RECT.x + 10)),
}
}
}
}
update_game :: proc(state: ^GameState) {
using state
// If we're entering the game screen then we need to setup initial state of the game variables
if last_frame_screen != .GAMEPLAY {
setup_game(state)
log.info("Done setting up game")
}
// Press enter to change to ENDING screen
if (rl.IsKeyPressed(rl.KeyboardKey.ENTER)) {
state.screen = .ENDING
log.info("Updated screen enum", state.screen)
}
// Press space to change to fire
if (rl.IsKeyPressed(rl.KeyboardKey.SPACE)) {
log.info("FIRE!")
bullet := &bullets[bullet_index]
bullet.alive = true
bullet.position = player_pos
bullet.position.y = bullet.position.y - f32((PLAYER_RECT.y / 2) + BULLET_RECT.y / 2)
}
if (rl.IsKeyDown(rl.KeyboardKey.RIGHT)) {
player_pos.x = player_pos.x + f32(PLAYER_SPEED * delta_time)
}
if (rl.IsKeyDown(rl.KeyboardKey.LEFT)) {
player_pos.x = player_pos.x - f32(PLAYER_SPEED * delta_time)
}
// movement update
{
for &bullet in bullets {
if bullet.alive {
bullet.position.y = bullet.position.y - f32(BULLET_SPEED * delta_time)
}
}
}
}
draw_game :: proc(state: ^GameState) {
using state
rl.DrawRectangle(0, 0, state.screen_width, state.screen_height, rl.BLACK)
// rl.DrawText("GAMEPLAY SCREEN", 20, 20, 40, rl.MAROON)
// rl.DrawText("PRESS ENTER or TAP to JUMP to ENDING SCREEN", 130, 220, 20, rl.MAROON)
rl.DrawCircle(c.int(player_pos.x), c.int(player_pos.y), f32(PLAYER_RECT.x / 2), rl.RED)
for row in 0 ..< ALIEN_ROWS {
for alien in 0 ..< ALIENS_PER_ROW {
alien := &aliens[(row * ALIENS_PER_ROW) + alien]
rl.DrawCircle(
c.int(alien.position.x),
c.int(alien.position.y),
f32(ALIEN_RECT.x / 2),
rl.YELLOW,
)
}
}
for &bullet in bullets {
if !bullet.alive { continue }
rl.DrawCircle(c.int(bullet.position.x), c.int(bullet.position.y), f32(BULLET_RECT.x / 2), rl.WHITE)
}
// rl.DrawText("GAMEPLAY SCREEN", 20, 20, 40, rl.MAROON)
}

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main.odin Normal file
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package space_invaders
import "core:c"
import "core:log"
import glm "core:math/linalg/glsl"
import rl "vendor:raylib"
// orignal resolution of space invaders
// 256 x 224 px
GameState :: struct {
// window
target_fps: c.int,
title: cstring,
screen_width: c.int,
screen_height: c.int,
// frame stats
frame_counter: int,
current_frame_time: f64,
last_frame_time: f64,
delta_time: f64,
// game vars
screen: GameScreen,
previous_screen: GameScreen,
last_frame_screen: GameScreen,
aliens: #soa[ALIENS]Alien,
bullets: #soa[MAX_BULLETS]Bullet,
bullet_index: int,
player_pos: glm.vec2,
player_health: c.int,
player_score: c.int,
}
state: GameState
setup :: proc(state: ^GameState) {
using state
target_fps = 60
screen_width = 800
screen_height = 600
title = "Space Invaders (raylib+odin-lang edition)"
current_frame_time = rl.GetTime()
previous_screen = .LOGO
screen = .GAMEPLAY
rl.SetTargetFPS(target_fps)
}
update :: proc(state: ^GameState) {
using state
frame_counter += 1
last_frame_time = current_frame_time
current_frame_time = rl.GetTime()
delta_time = current_frame_time - last_frame_time
update_screen(state)
}
draw :: proc(state: ^GameState) {
rl.BeginDrawing()
rl.ClearBackground(rl.RAYWHITE)
draw_screen(state)
rl.EndDrawing()
}
main :: proc() {
context.logger = log.create_console_logger()
log.info(state.screen)
setup(&state)
rl.InitWindow(state.screen_width, state.screen_height, state.title)
defer rl.CloseWindow()
for !rl.WindowShouldClose() {
update(&state)
draw(&state)
}
}

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screens.odin Normal file
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package space_invaders
import "core:log"
import rl "vendor:raylib"
GameScreen :: enum {
LOGO,
TITLE,
GAMEPLAY,
ENDING,
}
update_screen :: proc(state: ^GameState) {
using state
switch screen {
case .LOGO:
{
// Wait for 2 seconds (120 frames) before jumping to TITLE screen
if (frame_counter > int(target_fps * 2)) {
previous_screen = screen
screen = .TITLE
log.info("Updated screen enum", screen)
}
}
case .TITLE:
{
// Press enter to change to GAMEPLAY screen
if (rl.IsKeyPressed(rl.KeyboardKey.ENTER)) {
previous_screen = screen
screen = .GAMEPLAY
log.info("Updated screen enum", screen)
}
}
case .GAMEPLAY:
{
update_game(state)
}
case .ENDING:
{
// Press enter to return to TITLE screen
if (rl.IsKeyPressed(rl.KeyboardKey.ENTER)) {
previous_screen = screen
screen = .TITLE
log.info("Updated screen enum", screen)
}
}
}
if last_frame_screen != screen {
log.infof("Current screen: %v, previous screen: %v", screen, previous_screen)
}
last_frame_screen = screen
}
draw_screen :: proc(state: ^GameState) {
{
switch state.screen {
case .LOGO:
{
// TODO: Draw LOGO screen here!
rl.DrawText("SPACE INVADERS", 220, 220, 40, rl.GREEN)
rl.DrawText("WAIT for 2 SECONDS...", 290, 400, 20, rl.GRAY)
}
case .TITLE:
{
// TODO: Draw TITLE screen here!
rl.DrawRectangle(0, 0, state.screen_width, state.screen_height, rl.GREEN)
rl.DrawText("TITLE SCREEN", 20, 20, 40, rl.DARKGREEN)
rl.DrawText(
"PRESS ENTER or TAP to JUMP to GAMEPLAY SCREEN",
120,
220,
20,
rl.DARKGREEN,
)
}
case .GAMEPLAY:
{
draw_game(state)
}
case .ENDING:
{
// TODO: Draw ENDING screen here!
rl.DrawRectangle(0, 0, state.screen_width, state.screen_height, rl.BLUE)
rl.DrawText("ENDING SCREEN", 20, 20, 40, rl.DARKBLUE)
rl.DrawText(
"PRESS ENTER or TAP to RETURN to TITLE SCREEN",
120,
220,
20,
rl.DARKBLUE,
)
}
}
}
}