From 32b32a88bf0668968c1d988f8086a12b59b35e00 Mon Sep 17 00:00:00 2001
From: Logen Kain <logen@sudotask.com>
Date: Wed, 17 Jan 2018 17:36:21 -0700
Subject: [PATCH] Add drag; Add window collision; Add quit key

---
 main.go | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 89 insertions(+), 4 deletions(-)

diff --git a/main.go b/main.go
index f68f1d5..f7fc137 100644
--- a/main.go
+++ b/main.go
@@ -71,6 +71,12 @@ func run() {
 	playerX := win.Bounds().Max.X / 2
 	playerY := win.Bounds().Max.Y / 8
 
+	var playerTopSpeed float64 = 350
+	var playerAcceleration float64 = 0.15 * playerTopSpeed
+	var playerCurrentSpeed float64 = 0
+	var playerDrag float64 = 1
+	var playerXVelocity float64 = 0
+	var playerYVelocity float64 = 0
 	var myVec = pixel.Vec{playerX, playerY}
 
 	last := time.Now()
@@ -97,9 +103,35 @@ func run() {
 			angle -= 3 * dt
 
 		}
+
+		if win.Pressed(pixelgl.KeyEscape) {
+			win.SetClosed(true)
+		}
+
 		if win.Pressed(pixelgl.KeyUp) {
-			playerX += math.Cos(angle-(270*math.Pi)/180) * 300 * dt
-			playerY += math.Sin(angle-(270*math.Pi)/180) * 300 * dt
+			if playerCurrentSpeed < playerTopSpeed {
+				playerCurrentSpeed += playerAcceleration
+			}
+
+			playerXVelocity +=
+				math.Cos(angle-(270*math.Pi)/180) * playerCurrentSpeed * dt
+			playerYVelocity +=
+				math.Sin(angle-(270*math.Pi)/180) * playerCurrentSpeed * dt
+
+			if playerXVelocity > playerTopSpeed {
+				playerXVelocity = playerTopSpeed
+			}
+			if playerXVelocity < playerTopSpeed*-1 {
+				playerXVelocity = playerTopSpeed * -1
+			}
+
+			if playerYVelocity > playerTopSpeed {
+				playerYVelocity = playerTopSpeed
+			}
+			if playerYVelocity < playerTopSpeed*-1 {
+				playerYVelocity = playerTopSpeed * -1
+			}
+
 		}
 		if win.Pressed(pixelgl.KeyDown) {
 
@@ -123,13 +155,66 @@ func run() {
 			angle = angle + (360*math.Pi)/180
 		}
 
+		if playerCurrentSpeed > 0 {
+			playerCurrentSpeed -= playerDrag * dt
+		}
+
+		if playerCurrentSpeed < 0 {
+			playerCurrentSpeed = 0
+		}
+
+		if playerX >= win.Bounds().Max.X-10 {
+			playerXVelocity = -25
+		}
+		if playerX <= win.Bounds().Min.X+10 {
+			playerXVelocity = 25
+		}
+
+		if playerY >= win.Bounds().Max.Y-10 {
+			playerYVelocity = -25
+		}
+		if playerY <= win.Bounds().Min.Y+10 {
+			playerYVelocity = 25
+		}
+
+		playerX += playerXVelocity * dt
+		playerY += playerYVelocity * dt
+
+		if playerYVelocity > 0 {
+			playerYVelocity -= playerDrag
+			if playerYVelocity < 0 {
+				playerYVelocity = 0
+			}
+		}
+
+		if playerYVelocity < 0 {
+			playerYVelocity += playerDrag
+			if playerYVelocity > 0 {
+				playerYVelocity = 0
+			}
+		}
+
+		if playerXVelocity > 0 {
+			playerXVelocity -= playerDrag
+			if playerXVelocity < 0 {
+				playerXVelocity = 0
+			}
+		}
+
+		if playerXVelocity < 0 {
+			playerXVelocity += playerDrag
+			if playerXVelocity > 0 {
+				playerXVelocity = 0
+			}
+		}
+
 		win.Update()
 
 		frames++
 		select {
 		case <-second:
-			win.SetTitle(fmt.Sprintf("%s | FPS: %d | Degrees: %f %f", cfgMain.Title,
-				frames, angleInDegrees, angle))
+			win.SetTitle(fmt.Sprintf("%s | FPS: %d | playerYSpeed: %f", cfgMain.Title,
+				frames, playerYVelocity))
 			frames = 0
 		default:
 		}