From: Matthew Owens <matthew@owens.tech>
Date: Sat, 3 Oct 2020 12:00:09 +0000 (+0100)
Subject: added ball bouncing
X-Git-Url: https://git.owens.tech///git?a=commitdiff_plain;h=8011e369413e7d7cd72d655e6f3db8422e3e176f;p=pong.git

added ball bouncing
---

diff --git a/src/main.c b/src/main.c
index c0cb765..20cd0a6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -31,30 +31,31 @@ static const Vec2di baseWindowSize = { 1920, 1080 };
 static Vec2di windowSize;
 static Vec2df windowScale;
 
-Vbox pad, pad2, ball;
+Vbox ball;
+Vbox pads[2];
 Vec2df vline[2];
 
 static void paddle_init()
 {
 	// pad
-	pad.r.w = 192 * windowScale.x;
-	pad.r.h = 32 * windowScale.y;
+	pads[0].r.w = 192 * windowScale.x;
+	pads[0].r.h = 32 * windowScale.y;
 
-	pad.r.x = (windowSize.x / 2) - (pad.r.w / 2);
-	pad.r.y = windowSize.y - ((windowSize.y / 8));
+	pads[0].r.x = (windowSize.x / 2) - (pads[0].r.w / 2);
+	pads[0].r.y = windowSize.y - ((windowSize.y / 8));
 
-	pad.c.r = pad.c.g = pad.c.b = 0x55;
-	pad.c.a = 0xff;
+	pads[0].c.r = pads[0].c.g = pads[0].c.b = 0x55;
+	pads[0].c.a = 0xff;
 
-	// pad2
-	pad2.r.w = 192 * windowScale.x;
-	pad2.r.h = 32 * windowScale.y;
+	// pads[1]
+	pads[1].r.w = 192 * windowScale.x;
+	pads[1].r.h = 32 * windowScale.y;
 
-	pad2.r.x = (windowSize.x / 2) - (pad2.r.w / 2);
-	pad2.r.y = windowSize.y / 8 - pad2.r.h;
+	pads[1].r.x = (windowSize.x / 2) - (pads[1].r.w / 2);
+	pads[1].r.y = windowSize.y / 8 - pads[1].r.h;
 
-	pad2.c.r = pad2.c.g = pad2.c.b = 0x55;
-	pad2.c.a = 0xff;
+	pads[1].c.r = pads[1].c.g = pads[1].c.b = 0x55;
+	pads[1].c.a = 0xff;
 }
 
 static void ball_init()
@@ -81,24 +82,26 @@ static void vbox_render(const Vbox *b)
 
 static void paddle_update(const Uint8* keyStates, float dt)
 {
-	pad.v.x = 0;
+	pads[0].v.x = 0;
+	pads[1].v.x = 0;
 
-	if(keyStates[SDL_SCANCODE_LEFT] || keyStates[SDL_SCANCODE_A]) {
-		pad.v.x = -speed;
-	}
-
-	if(keyStates[SDL_SCANCODE_RIGHT] || keyStates[SDL_SCANCODE_D]) {
-		pad.v.x = speed;
-	}
+	if(keyStates[SDL_SCANCODE_RIGHT]) { pads[0].v.x += speed; }
+	if(keyStates[SDL_SCANCODE_LEFT]) { pads[0].v.x -= speed; }
+	if(keyStates[SDL_SCANCODE_D]) { pads[1].v.x += speed; }
+	if(keyStates[SDL_SCANCODE_A]) { pads[1].v.x -= speed; }
 
-	pad.r.x += pad.v.x * dt;
+	for(int i = 0; i < 2; ++i){
+		pads[i].r.x += pads[i].v.x * dt;
 
-	// screen bounds check
-	if(pad.r.x + pad.r.w > windowSize.x) { pad.r.x = windowSize.x - pad.r.w; }
-	if(pad.r.x < 0 ) { pad.r.x = 0; }
+		// screen bounds check
+		if(pads[i].r.x + pads[i].r.w > windowSize.x){
+			pads[i].r.x = windowSize.x - pads[i].r.w;
+		}
+		if(pads[i].r.x < 0 ) { pads[i].r.x = 0; }
+	}
 }
 
-static void ball_update(float dt)
+static void ball_update(const Uint8 *keyStates, float dt)
 {
 	bool collisionResponded = false;
 	float halfw = ball.r.w / 2;
@@ -117,29 +120,40 @@ static void ball_update(float dt)
 	else if (ball.v.y < 0) {vline[1].y -= halfh; }
 
 	// are we going to collide with the paddle? 
-	{
-		int willCollide = lr_collision(vline[0], vline[1], pad.r, NULL);
+	int collidingWith = -1;
+	for(int i = 0; i < 2; ++i) {
+		int willCollide = lr_collision(vline[0], vline[1], pads[i].r, NULL);
 		// left/right/top/bottom
 		switch(willCollide) {
-			//TODO: set ball loc to colliding wall, invert vel & skip vel add
 			case 1:
-				ball.r.x = pad.r.x - ball.r.w;
+				ball.r.x = pads[i].r.x - ball.r.w;
 				ball.v.x *= -1;
 				break;
 			case 2:
-				ball.r.x = pad.r.x + pad.r.w;
+				ball.r.x = pads[i].r.x + pads[i].r.w;
 				ball.v.x *= -1;
 				break;
 			case 3:
-				ball.r.y = pad.r.y - ball.r.h;
+				ball.r.y = pads[i].r.y - ball.r.h;
 				ball.v.y *= -1;
 				break;
 			case 4:
-				ball.r.y = pad.r.y + pad.r.h;
+				ball.r.y = pads[i].r.y + pads[i].r.h;
 				ball.v.y *= -1;
 				break;
 		}
-		if(willCollide != 0) { collisionResponded = true; }
+		if(willCollide != 0){
+			collisionResponded = true;
+			collidingWith = i;
+		}
+	}
+
+	if(collidingWith == 0) {
+		if(keyStates[SDL_SCANCODE_RIGHT]) { ball.v.x += speed; }
+		if(keyStates[SDL_SCANCODE_LEFT]) { ball.v.x -= speed; }
+	} else if (collidingWith == 1) {
+		if(keyStates[SDL_SCANCODE_D]) { ball.v.x += speed; }
+		if(keyStates[SDL_SCANCODE_A]) { ball.v.x -= speed; }
 	}
 
 	// applying velocity if needed
@@ -221,7 +235,7 @@ static void update()
 
 	while(ts_phys_required(nPhysUpdates)){
 		paddle_update(keyStates, ts_delta());
-		ball_update(ts_delta());
+		ball_update(keyStates, ts_delta());
 		nPhysUpdates++;
 	}
 }
@@ -230,8 +244,8 @@ static void render()
 {
 	SDL_SetRenderDrawColor(renderer, bgClr.r, bgClr.g, bgClr.b, bgClr.a);
 	SDL_RenderClear(renderer);
-	vbox_render(&pad);
-	vbox_render(&pad2);
+	vbox_render(&pads[0]);
+	vbox_render(&pads[1]);
 	vbox_render(&ball);
 	SDL_SetRenderDrawColor(renderer, 0x00, 0xff, 0x00, 0xff);
 	SDL_RenderDrawLine(renderer, vline[0].x, vline[0].y, vline[1].x, vline[1].y);