Center printout rendering, fix printout gui not responding to page turning inputs.

Fixes:
- Printouts being drawn slightly offset to the left in all cases, noticeable mainly when in item frames.
- Printout text two pixels off center within the background.
- Printout GUI not responding to left/right arrows. Scrolling seemed to work but same fix was added there for consistency.

src/main/java/dan200/computercraft/client/gui/GuiPrintout.java

@@ -53,8 +53,7 @@ public class GuiPrintout extends AbstractContainerScreen<ContainerHeldItem>
     @Override
     public boolean keyPressed( int key, int scancode, int modifiers )
     {
-        if( super.keyPressed( key, scancode, modifiers ) ) return true;
-
+        // Check for key presses.
         if( key == GLFW.GLFW_KEY_RIGHT )
         {
             if( page < pages - 1 ) page++;
@@ -67,13 +66,16 @@ public class GuiPrintout extends AbstractContainerScreen<ContainerHeldItem>
             return true;
         }
 
+        // Otherwise, default to parent function
+        if( super.keyPressed( key, scancode, modifiers ) ) return true;
+
         return false;
     }
 
     @Override
     public boolean mouseScrolled( double x, double y, double delta )
     {
-        if( super.mouseScrolled( x, y, delta ) ) return true;
+        // Check for key presses.
         if( delta < 0 )
         {
             // Scroll up goes to the next page
@@ -88,6 +90,9 @@ public class GuiPrintout extends AbstractContainerScreen<ContainerHeldItem>
             return true;
         }
 
+        // Otherwise, default to parent function
+        if( super.mouseScrolled( x, y, delta ) ) return true;
+
         return false;
     }
 

src/main/java/dan200/computercraft/client/render/ItemPrintoutRenderer.java

@@ -63,7 +63,7 @@ public final class ItemPrintoutRenderer extends ItemMapLikeRenderer
         double height = LINES_PER_PAGE * FONT_HEIGHT + Y_TEXT_MARGIN * 2;
 
         // Non-books will be left aligned
-        if( !book ) width += offsetAt( pages );
+        if( !book ) width += offsetAt( pages - 1 );
 
         double visualWidth = width, visualHeight = height;
 

src/main/java/dan200/computercraft/client/render/PrintoutRenderer.java

@@ -32,12 +32,12 @@ public final class PrintoutRenderer
     /**
      * Padding between the left and right of a page and the text.
      */
-    public static final int X_TEXT_MARGIN = 13;
+    public static final int X_TEXT_MARGIN = 11;
 
     /**
      * Padding between the top and bottom of a page and the text.
      */
-    public static final int Y_TEXT_MARGIN = 11;
+    public static final int Y_TEXT_MARGIN = 10;
 
     /**
      * Width of the extra page texture.