comments and better welcome message

main.c

@@ -3,19 +3,27 @@
 #include <malloc.h>
 
 #include <coreinit/screen.h>
+#include <coreinit/cache.h>
 #include <vpad/input.h>
+#include <whb/proc.h>
+
+void quit(void);
+void welcome(OSScreenID screen);
+void drawScreen(OSScreenID screen, VPADTouchData gamepad, int color);
 
 int main(int argc, char **argv)
 {
-
+    // initialize ProcUI and OSScreen
     WHBProcInit();
     OSScreenInit();
 
+    // allocate memory to render both displays and align them
     size_t tvBufferSize = OSScreenGetBufferSizeEx(SCREEN_TV);
     size_t drcBufferSize = OSScreenGetBufferSizeEx(SCREEN_DRC);
     void *tvBuffer = memalign(0x100, tvBufferSize);
     void *drcBuffer = memalign(0x100, drcBufferSize);
 
+    // free used video memory and deinitialize OSScreen and ProcUI
     void quit(void)
     {
         if (tvBuffer)
@@ -24,17 +32,20 @@ int main(int argc, char **argv)
             free(drcBuffer);
         OSScreenShutdown();
         WHBProcShutdown();
-    }
+    };
 
+    // check if memory allocation was successful otherwise kill program
     if (!tvBuffer || !drcBuffer)
     {
         quit();
         return 1;
     }
 
+    // tell the screens where the allocated memory is
     OSScreenSetBufferEx(SCREEN_TV, tvBuffer);
     OSScreenSetBufferEx(SCREEN_DRC, drcBuffer);
 
+    // enable control of the displays
     OSScreenEnableEx(SCREEN_TV, true);
     OSScreenEnableEx(SCREEN_DRC, true);
 
@@ -45,11 +56,51 @@ int main(int argc, char **argv)
     bool vpad_fatal = false;
     uint32_t penColor = 0xFFFFFF00;
 
-    OSScreenPutFontEx(SCREEN_TV, 0, 0, "SimpleDrawU (TV).");
-    OSScreenPutFontEx(SCREEN_DRC, 0, 0, "SimpleDrawU (Gamepad).");
+    // welcome message
+    void welcome(OSScreenID screen)
+    {
+        OSScreenPutFontEx(screen, 0, 0, "Welcome to SimpleDrawU!");
+        OSScreenPutFontEx(screen, 0, 1, "A is red.");
+        OSScreenPutFontEx(screen, 0, 2, "B is yellow.");
+        OSScreenPutFontEx(screen, 0, 3, "X is blue.");
+        OSScreenPutFontEx(screen, 0, 4, "Y is green.");
+        OSScreenPutFontEx(screen, 0, 5, "Plus is white.");
+        OSScreenPutFontEx(screen, 0, 6, "Minus is black (erase).");
+        OSScreenPutFontEx(screen, 0, 7, "Press both Plus and Minus");
+        OSScreenPutFontEx(screen, 0, 8, "to clear the screen, enjoy!");
+    }
+    welcome(SCREEN_TV);
+    welcome(SCREEN_DRC);
 
+    // define color palette
+    enum penColor
+    {
+        white = 0xFFFFFF00,
+        black = 0x00000000,
+        red = 0xBF5B5B00,
+        yellow = 0xC6B95500,
+        blue = 0x3C8D8800,
+        green = 0x86B46000,
+    };
+
+    // draw pixels to screen
+    void drawScreen(OSScreenID screen, VPADTouchData gamepad, int color)
+    {
+        OSScreenPutPixelEx(screen, gamepad.x - 1, gamepad.y - 1, color);
+        OSScreenPutPixelEx(screen, gamepad.x + 1, gamepad.y + 1, color);
+        OSScreenPutPixelEx(screen, gamepad.x + 1, gamepad.y, color);
+        OSScreenPutPixelEx(screen, gamepad.x - 1, gamepad.y, color);
+        OSScreenPutPixelEx(screen, gamepad.x, gamepad.y, color);
+        OSScreenPutPixelEx(screen, gamepad.x, gamepad.y + 1, color);
+        OSScreenPutPixelEx(screen, gamepad.x, gamepad.y - 1, color);
+        OSScreenPutPixelEx(screen, gamepad.x - 1, gamepad.y + 1, color);
+        OSScreenPutPixelEx(screen, gamepad.x + 1, gamepad.y - 1, color);
+    };
+
+    // while ProcUI is running
     while (WHBProcIsRunning())
     {
+        // read gamepad inputs and check if error
         VPADRead(VPAD_CHAN_0, &status, 1, &error);
         switch (error)
         {
@@ -77,59 +128,48 @@ int main(int argc, char **argv)
             break;
 
         // clear screen
-        if ((status.trigger & VPAD_BUTTON_PLUS) && (status.trigger & VPAD_BUTTON_MINUS))
+        if ((status.hold & VPAD_BUTTON_PLUS) && (status.hold & VPAD_BUTTON_MINUS))
         {
-            OSScreenClearBufferEx(SCREEN_TV, 0x00000000);
-            OSScreenClearBufferEx(SCREEN_DRC, 0x00000000);
+            OSScreenClearBufferEx(SCREEN_TV, black);
+            OSScreenClearBufferEx(SCREEN_DRC, black);
         }
 
         // select color
-        if (status.trigger & VPAD_BUTTON_PLUS)
+        if (status.hold & VPAD_BUTTON_PLUS)
         {
-            penColor = 0xFFFFFF00;
-        } // white
-        if (status.trigger & VPAD_BUTTON_MINUS)
+            penColor = white;
+        }
+        if (status.hold & VPAD_BUTTON_MINUS)
         {
-            penColor = 0x00000000;
-        } // black
-        if (status.trigger & VPAD_BUTTON_A)
+            penColor = black;
+        }
+        if (status.hold & VPAD_BUTTON_A)
         {
-            penColor = 0xBF5B5B00;
-        } // red
-        if (status.trigger & VPAD_BUTTON_B)
+            penColor = red;
+        }
+        if (status.hold & VPAD_BUTTON_B)
         {
-            penColor = 0xC6B95500;
-        } // yellow
-        if (status.trigger & VPAD_BUTTON_X)
+            penColor = yellow;
+        }
+        if (status.hold & VPAD_BUTTON_X)
         {
-            penColor = 0x3C8D8800;
-        } // blue
-        if (status.trigger & VPAD_BUTTON_Y)
+            penColor = blue;
+        }
+        if (status.hold & VPAD_BUTTON_Y)
         {
-            penColor = 0x86B46000;
-        } // green
+            penColor = green;
+        }
 
         // draw on screen
         if (gamepadTouchScreen.touched)
         {
-            OSScreenPutPixelEx(SCREEN_TV, gamepadTouchScreen.x - 1, gamepadTouchScreen.y - 1, penColor);
-            OSScreenPutPixelEx(SCREEN_TV, gamepadTouchScreen.x + 1, gamepadTouchScreen.y + 1, penColor);
-            OSScreenPutPixelEx(SCREEN_TV, gamepadTouchScreen.x, gamepadTouchScreen.y, penColor);
-            OSScreenPutPixelEx(SCREEN_TV, gamepadTouchScreen.x - 1, gamepadTouchScreen.y + 1, penColor);
-            OSScreenPutPixelEx(SCREEN_TV, gamepadTouchScreen.x + 1, gamepadTouchScreen.y - 1, penColor);
-
-            OSScreenPutPixelEx(SCREEN_DRC, gamepadTouchScreen.x + 1, gamepadTouchScreen.y + 1, penColor);
-            OSScreenPutPixelEx(SCREEN_DRC, gamepadTouchScreen.x - 1, gamepadTouchScreen.y - 1, penColor);
-            OSScreenPutPixelEx(SCREEN_DRC, gamepadTouchScreen.x, gamepadTouchScreen.y, penColor);
-            OSScreenPutPixelEx(SCREEN_DRC, gamepadTouchScreen.x - 1, gamepadTouchScreen.y + 1, penColor);
-            OSScreenPutPixelEx(SCREEN_DRC, gamepadTouchScreen.x + 1, gamepadTouchScreen.y - 1, penColor);
+            drawScreen(SCREEN_TV, gamepadTouchScreen, penColor);
+            drawScreen(SCREEN_DRC, gamepadTouchScreen, penColor);
         }
-        /*  Flush all caches - read the tutorial, please! */
+
+        // commit drawing to the screen
         DCFlushRange(tvBuffer, tvBufferSize);
         DCFlushRange(drcBuffer, drcBufferSize);
-
-        /*  Flip buffers - the text is now on screen! Flipping is kinda like
-            committing your graphics changes. */
         OSScreenFlipBuffersEx(SCREEN_TV);
         OSScreenFlipBuffersEx(SCREEN_DRC);
     }