Add support for 4:3 aspect ratio

Author: olafkryus

README.md

@@ -44,6 +44,7 @@ some buffer overflows have been fixed.
 | Alt+(Keypad) Plus | Increase window size |
 | Alt+(Keypad) Minus | Decrease window size |
 | Alt+R | Reset window if stretched |
+| Alt+A | Toggle 4:3 aspect ratio |
 
 ## Build
 

SDLPORT.PAS

@@ -28,7 +28,7 @@ implementation
         xRes = 320;
         yRes = 200;
         targetFrames = 70;
-        aspect: real = xRes / yRes;
+        aspectRes: real = xRes / yRes;
 
   var windowMultiplier: integer;
       window: PSDL_Window;
@@ -41,6 +41,7 @@ implementation
 
       windowResized: boolean;
       fullScreen: boolean;
+      aspect: real;
 
       timer: TSDL_TimerID;
       frameCount, lastFrameCount, subFrameCount, lastFrameTick: LongInt;
@@ -92,7 +93,7 @@ end;
 
 procedure ResetWindowSize;
 begin
-  SDL_SetWindowSize(window, xRes * windowMultiplier, yRes * windowMultiplier);
+  SDL_SetWindowSize(window, xRes * windowMultiplier, Round(yRes * windowMultiplier * aspectRes / aspect));
   windowResized := true;
 end;
 
@@ -104,6 +105,7 @@ end;
 procedure Init;
 begin
   windowMultiplier := 2;
+  aspect := aspectRes;
 
   if SDL_Init( SDL_INIT_VIDEO or SDL_INIT_TIMER ) < 0 then HALT;
 
@@ -335,6 +337,15 @@ begin
                   exit
                 end;
               end;
+            SDL_SCANCODE_A :
+              begin
+                if (aspect <> aspectRes) then
+                  aspect := aspectRes
+                else
+                  aspect := 4 / 3;
+                ResetWindowSize;
+                exit;
+              end;
           end;
         end;
 

SJ3.PAS

@@ -5704,6 +5704,7 @@ begin
  writeln(' * Alt+(Keypad) Plus  : Increase window size');
  writeln(' * Alt+(Keypad) Minus : Decrease window size');
  writeln(' * Alt+R              : Reset window if stretched');
+ writeln(' * Alt+A              : Toggle 4:3 aspect ratio');
  writeln('');
  writeln('-------');
  writeln('');