From 1ae4028603087daa228ba725e6f0011af10b8425 Mon Sep 17 00:00:00 2001
From: Gregory Eremin <g@erem.in>
Date: Wed, 30 Sep 2015 14:56:05 +0300
Subject: [PATCH] Define constants, set pad move limits

---
 main.cpp | 48 +++++++++++++++++++++++++++++++++---------------
 1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/main.cpp b/main.cpp
index 19deff5..90650d2 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,6 +1,18 @@
 #include <iostream>
 #include "SDL2/SDL.h"
 
+#define SCREEN_X 100
+#define SCREEN_Y 100
+#define SCREEN_WIDTH 640
+#define SCREEN_HEIGHT 480
+#define PAD_WIDTH 200
+#define PAD_HEIGHT 20
+
+#define KEY_MOVE_STEP 5
+
+#define BG_COLOR 0, 0, 0, 255
+#define PAD_COLOR 0, 0, 255, 255
+
 int main(int argc, char const *argv[]) {
     if (SDL_Init(SDL_INIT_VIDEO) != 0) {
         std::cout << "SDL_Init Error: " << SDL_GetError() << std::endl;
@@ -8,10 +20,10 @@ int main(int argc, char const *argv[]) {
     }
 
     SDL_Window *window = SDL_CreateWindow(
-        "Breakout",      // Title
-        100, 100,        // X, Y
-        640, 480,        // Width, Height
-        SDL_WINDOW_SHOWN // Visibility
+        "Breakout",
+        SCREEN_X, SCREEN_Y,
+        SCREEN_WIDTH, SCREEN_HEIGHT,
+        SDL_WINDOW_SHOWN
     );
     if (window == nullptr) {
         std::cout << "SDL_CreateWindow Error: " << SDL_GetError() << std::endl;
@@ -32,19 +44,19 @@ int main(int argc, char const *argv[]) {
     }
 
     // Setting background color to black
-    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+    SDL_SetRenderDrawColor(renderer, BG_COLOR);
     SDL_RenderClear(renderer);
 
     // Creat a rect at pos ( 50, 50 ) that's 50 pixels wide and 50 pixels high.
     SDL_Rect platform = {
-        .x = (640 - 200) / 2,
-        .y = (480 - 20),
-        .w = 200,
-        .h = 20
+        .x = (SCREEN_WIDTH - PAD_WIDTH) / 2,
+        .y = (SCREEN_HEIGHT - PAD_HEIGHT),
+        .w = PAD_WIDTH,
+        .h = PAD_HEIGHT
     };
 
     // Set render color to blue ( rect will be rendered in this color )
-    SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255);
+    SDL_SetRenderDrawColor(renderer, PAD_COLOR);
 
     // Render rect
     SDL_RenderFillRect(renderer, &platform);
@@ -65,22 +77,28 @@ int main(int argc, char const *argv[]) {
                     quit = true;
                     break;
                 case SDLK_LEFT:
-                    platform.x-=5;
+                    platform.x -= KEY_MOVE_STEP;
                     break;
                 case SDLK_RIGHT:
-                    platform.x+=5;
+                    platform.x += KEY_MOVE_STEP;
                     break;
                 }
             }
             if (e.type == SDL_MOUSEMOTION) {
-                platform.x = e.motion.x - 100;
+                platform.x = e.motion.x - PAD_WIDTH / 2;
+            }
+
+            if (platform.x < 0) {
+                platform.x = 0;
+            } else if (platform.x > SCREEN_WIDTH - PAD_WIDTH) {
+                platform.x = SCREEN_WIDTH - PAD_WIDTH;
             }
         }
 
         // Re-rendering
-        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+        SDL_SetRenderDrawColor(renderer, BG_COLOR);
         SDL_RenderClear(renderer);
-        SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255);
+        SDL_SetRenderDrawColor(renderer, PAD_COLOR);
         SDL_RenderFillRect(renderer, &platform);
         SDL_RenderPresent(renderer);
         SDL_Delay(1);