New example : 2d camera platform

This commit is contained in:
Per Hultqvist 2024-10-15 15:18:58 +02:00
parent a33e6f490b
commit afe70ad4c8

View file

@ -0,0 +1,261 @@
package main
import rl "github.com/gen2brain/raylib-go/raylib"
const (
screenWidth = 800
screenHeight = 450
gravity = 400
playerJumpSpeed = 350.0
playerHORSpeed = 200.0
)
type Player struct {
position rl.Vector2
speed float32
canJump bool
}
type EnvironmentItem struct {
rect rl.Rectangle
blocking bool
color rl.Color
}
type cameraUpdater func(*rl.Camera2D, *Player, []EnvironmentItem, float32)
// These 3 variables are used only for camera 4,
// but they need to be declared on module level
// for camera 4 to work (static in C)
var eveningOut = false
var evenOutSpeed float32 = 700
var evenOutTarget float32 = 0
func main() {
rl.InitWindow(screenWidth, screenHeight, "raylib [core] example - 2d camera platformer")
player := Player{
position: rl.NewVector2(400, 280),
speed: 0,
canJump: false,
}
envItems := []EnvironmentItem{
{rect: rl.Rectangle{Width: 1000, Height: 400}, blocking: false, color: rl.LightGray},
{rect: rl.Rectangle{Y: 400, Width: 1000, Height: 200}, blocking: true, color: rl.Gray},
{rect: rl.Rectangle{X: 300, Y: 200, Width: 400, Height: 10}, blocking: true, color: rl.Gray},
{rect: rl.Rectangle{X: 250, Y: 300, Width: 100, Height: 10}, blocking: true, color: rl.Gray},
{rect: rl.Rectangle{X: 650, Y: 300, Width: 100, Height: 10}, blocking: true, color: rl.Gray},
}
camera := rl.Camera2D{
Offset: rl.Vector2{X: screenWidth / 2, Y: screenHeight / 2},
Target: player.position,
Rotation: 0,
Zoom: 1,
}
cameraUpdaters := []cameraUpdater{
updateCameraCenter,
updateCameraCenterInsideMap,
updateCameraCenterSmoothFollow,
updateCameraEvenOutOnLanding,
updateCameraPlayerBoundsPush,
}
cameraDescriptions := []string{
"1. Follow player center",
"2. Follow player center, but clamp to map edges",
"3. Follow player center; smoothed",
"4. Follow player center horizontally; update player center vertically after landing",
"5. Player push camera on getting too close to screen edge",
}
cameraOption := 0
rl.SetTargetFPS(60)
for !rl.WindowShouldClose() {
deltaTime := rl.GetFrameTime()
updatePlayer(&player, envItems, deltaTime)
camera.Zoom += rl.GetMouseWheelMove() * 0.05
camera.Zoom = clamp(camera.Zoom, 0.25, 3)
if rl.IsKeyPressed(rl.KeyC) {
cameraOption = (cameraOption + 1) % len(cameraUpdaters)
}
// Call update camera function by its pointer
cameraUpdaters[cameraOption](&camera, &player, envItems, deltaTime)
// Draw
rl.BeginDrawing()
rl.ClearBackground(rl.RayWhite)
rl.BeginMode2D(camera)
for _, item := range envItems {
rl.DrawRectangleRec(item.rect, item.color)
}
playerRect := rl.Rectangle{
X: player.position.X - 20,
Y: player.position.Y - 40,
Width: 40,
Height: 40,
}
rl.DrawRectangleRec(playerRect, rl.Red)
rl.DrawCircleV(player.position, 5, rl.Gold)
rl.EndMode2D()
rl.DrawText("Controls:", 20, 20, 10, rl.Black)
rl.DrawText(" - Right/Left to move", 40, 40, 10, rl.DarkGray)
rl.DrawText(" - Space to jump", 40, 60, 10, rl.DarkGray)
rl.DrawText(" - Mouse Wheel to Zoom in-out, R to reset zoom", 40, 80, 10, rl.DarkGray)
rl.DrawText(" - C to change camera mode", 20, 100, 10, rl.Black)
rl.DrawText("Current Camera Mode:", 20, 120, 10, rl.DarkGray)
rl.DrawText(cameraDescriptions[cameraOption], 40, 140, 10, rl.DarkGray)
rl.EndDrawing()
}
rl.CloseWindow()
}
func updatePlayer(player *Player, envItems []EnvironmentItem, delta float32) {
if rl.IsKeyDown(rl.KeyLeft) {
player.position.X -= playerHORSpeed * delta
}
if rl.IsKeyDown(rl.KeyRight) {
player.position.X += playerHORSpeed * delta
}
if rl.IsKeyDown(rl.KeySpace) && player.canJump {
player.speed = -playerJumpSpeed
player.canJump = false
}
hitObstacle := false
for _, item := range envItems {
if item.blocking &&
item.rect.X <= player.position.X && item.rect.X+item.rect.Width >= player.position.X &&
item.rect.Y >= player.position.Y && item.rect.Y <= player.position.Y+player.speed*delta {
hitObstacle = true
player.speed = 0
player.position.Y = item.rect.Y
break
}
}
if !hitObstacle {
player.position.Y += player.speed * delta
player.speed += gravity * delta
player.canJump = false
} else {
player.canJump = true
}
}
func updateCameraCenter(camera *rl.Camera2D, player *Player, _ []EnvironmentItem, _ float32) {
camera.Offset = rl.Vector2{X: screenWidth / 2, Y: screenHeight / 2}
camera.Target = player.position
}
func updateCameraCenterInsideMap(camera *rl.Camera2D, player *Player, envItems []EnvironmentItem, _ float32) {
camera.Offset = rl.Vector2{X: screenWidth / 2, Y: screenHeight / 2}
camera.Target = player.position
var minX, minY, maxX, maxY float32 = 1000, 1000, -1000, -10000
for _, item := range envItems {
minX = min(item.rect.X, minX)
maxX = max(item.rect.X+item.rect.Width, maxX)
minY = min(item.rect.Y, minY)
maxY = max(item.rect.Y+item.rect.Height, maxY)
}
maxV := rl.GetWorldToScreen2D(rl.Vector2{X: maxX, Y: maxY}, *camera)
minV := rl.GetWorldToScreen2D(rl.Vector2{X: minX, Y: minY}, *camera)
if maxV.X < screenWidth {
camera.Offset.X = screenWidth - (maxV.X - screenWidth/2)
}
if maxV.Y < screenHeight {
camera.Offset.Y = screenHeight - (maxV.Y - screenHeight/2)
}
if minV.X > 0 {
camera.Offset.X = screenWidth/2 - minV.X
}
if minV.Y > 0 {
camera.Offset.Y = screenHeight/2 - minV.Y
}
}
func updateCameraCenterSmoothFollow(camera *rl.Camera2D, player *Player, _ []EnvironmentItem, delta float32) {
var minSpeed, minEffectLength, fractionSpeed float32 = 30.0, 10.0, 0.8
camera.Offset = rl.Vector2{X: screenWidth / 2, Y: screenHeight / 2}
diff := rl.Vector2Subtract(player.position, camera.Target)
length := rl.Vector2Length(diff)
if length > minEffectLength {
speed := max(fractionSpeed*length, minSpeed)
camera.Target = rl.Vector2Add(camera.Target, rl.Vector2Scale(diff, speed*delta/length))
}
}
func updateCameraEvenOutOnLanding(camera *rl.Camera2D, player *Player, _ []EnvironmentItem, delta float32) {
camera.Offset = rl.Vector2{X: screenWidth / 2, Y: screenHeight / 2}
camera.Target.X = player.position.X
if eveningOut {
if evenOutTarget > camera.Target.Y {
camera.Target.Y += evenOutSpeed * delta
if camera.Target.Y > evenOutTarget {
camera.Target.Y = evenOutTarget
eveningOut = false
}
} else {
camera.Target.Y -= evenOutSpeed * delta
if camera.Target.Y < evenOutTarget {
camera.Target.Y = evenOutTarget
eveningOut = false
}
}
} else {
if player.canJump && player.speed == 0 && player.position.Y != camera.Target.Y {
eveningOut = true
evenOutTarget = player.position.Y
}
}
}
func updateCameraPlayerBoundsPush(camera *rl.Camera2D, player *Player, _ []EnvironmentItem, _ float32) {
bbox := rl.Vector2{X: 0.2, Y: 0.2}
bboxWorldMin := rl.GetScreenToWorld2D(rl.Vector2{X: (1 - bbox.X) * 0.5 * screenWidth, Y: (1 - bbox.Y) * 0.5 * screenHeight}, *camera)
bboxWorldMax := rl.GetScreenToWorld2D(rl.Vector2{X: (1 + bbox.X) * 0.5 * screenWidth, Y: (1 + bbox.Y) * 0.5 * screenHeight}, *camera)
camera.Offset = rl.Vector2{X: (1 - bbox.X) * 0.5 * screenWidth, Y: (1 - bbox.Y) * 0.5 * screenHeight}
if player.position.X < bboxWorldMin.X {
camera.Target.X = player.position.X
}
if player.position.Y < bboxWorldMin.Y {
camera.Target.Y = player.position.Y
}
if player.position.X > bboxWorldMax.X {
camera.Target.X = bboxWorldMin.X + (player.position.X - bboxWorldMax.X)
}
if player.position.Y > bboxWorldMax.Y {
camera.Target.Y = bboxWorldMin.Y + (player.position.Y - bboxWorldMax.Y)
}
}
func clamp(zoom float32, min float32, max float32) float32 {
if zoom < min {
return min
}
if zoom > max {
return max
}
return zoom
}