raylib-go/examples/physics/physac/restitution/main.go
2017-11-19 18:35:44 +01:00

96 lines
3.3 KiB
Go

package main
import (
"github.com/gen2brain/raylib-go/physics"
"github.com/gen2brain/raylib-go/raylib"
)
const (
velocity = 0.5
)
func main() {
screenWidth := float32(800)
screenHeight := float32(450)
raylib.SetConfigFlags(raylib.FlagMsaa4xHint)
raylib.InitWindow(int32(screenWidth), int32(screenHeight), "Physac [raylib] - physics restitution")
// Physac logo drawing position
logoX := int32(screenWidth) - raylib.MeasureText("Physac", 30) - 10
logoY := int32(15)
// Initialize physics and default physics bodies
physics.Init()
// Create floor rectangle physics body
floor := physics.NewBodyRectangle(raylib.NewVector2(screenWidth/2, screenHeight), screenWidth, 100, 10)
floor.Enabled = false // Disable body state to convert it to static (no dynamics, but collisions)
floor.Restitution = 1
// Create circles physics body
circleA := physics.NewBodyCircle(raylib.NewVector2(screenWidth*0.25, screenHeight/2), 30, 10)
circleA.Restitution = 0
circleB := physics.NewBodyCircle(raylib.NewVector2(screenWidth*0.5, screenHeight/2), 30, 10)
circleB.Restitution = 0.5
circleC := physics.NewBodyCircle(raylib.NewVector2(screenWidth*0.75, screenHeight/2), 30, 10)
circleC.Restitution = 1
raylib.SetTargetFPS(60)
for !raylib.WindowShouldClose() {
// Update created physics objects
physics.Update()
if raylib.IsKeyPressed(raylib.KeyR) { // Reset physics input
// Reset circles physics bodies position and velocity
circleA.Position = raylib.NewVector2(screenWidth*0.25, screenHeight/2)
circleA.Velocity = raylib.NewVector2(0, 0)
circleB.Position = raylib.NewVector2(screenWidth*0.5, screenHeight/2)
circleB.Velocity = raylib.NewVector2(0, 0)
circleC.Position = raylib.NewVector2(screenWidth*0.75, screenHeight/2)
circleC.Velocity = raylib.NewVector2(0, 0)
}
raylib.BeginDrawing()
raylib.ClearBackground(raylib.Black)
raylib.DrawFPS(int32(screenWidth)-90, int32(screenHeight)-30)
// Draw created physics bodies
for i, body := range physics.GetBodies() {
vertexCount := physics.GetShapeVerticesCount(i)
for j := 0; j < vertexCount; j++ {
// Get physics bodies shape vertices to draw lines
// NOTE: GetShapeVertex() already calculates rotation transformations
vertexA := body.GetShapeVertex(j)
jj := 0
if j+1 < vertexCount { // Get next vertex or first to close the shape
jj = j + 1
}
vertexB := body.GetShapeVertex(jj)
raylib.DrawLineV(vertexA, vertexB, raylib.Green) // Draw a line between two vertex positions
}
}
raylib.DrawText("Restitution amount", (int32(screenWidth)-raylib.MeasureText("Restitution amount", 30))/2, 75, 30, raylib.White)
raylib.DrawText("0", int32(circleA.Position.X)-raylib.MeasureText("0", 20)/2, int32(circleA.Position.Y)-7, 20, raylib.White)
raylib.DrawText("0.5", int32(circleB.Position.X)-raylib.MeasureText("0.5", 20)/2, int32(circleB.Position.Y)-7, 20, raylib.White)
raylib.DrawText("1", int32(circleC.Position.X)-raylib.MeasureText("1", 20)/2, int32(circleC.Position.Y)-7, 20, raylib.White)
raylib.DrawText("Press 'R' to reset example", 10, 10, 10, raylib.White)
raylib.DrawText("Physac", logoX, logoY, 30, raylib.White)
raylib.DrawText("Powered by", logoX+50, logoY-7, 10, raylib.White)
raylib.EndDrawing()
}
physics.Close() // Unitialize physics
raylib.CloseWindow()
}