- cleanup/comments for TDisplay.Create

- fading works now, it was broken because RenderW/H was not defined when SwapBuffers() was called for the first time. This caused glOrtho() to set the OpenGL error state. When fading was initialized in UDisplay this error-state was checked to see if glGenTextures failed. Although it didn't the error state was set because of the older error in glOrtho (Note: errors aren't reset after a successful OpenGL call), so it was wrongly assumed that no texture could be allocated.
This problem was fixed by defining RenderW/H before the first call of SwapBuffers and resetting OpenGL's error state before calling an OpenGL function whose error state is to be checked.


git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@1188 b956fd51-792f-4845-bead-9b4dfca2ff2c

1 files changed, 90 insertions, 131 deletions

diff --git a/Game/Code/Menu/UDisplay.pas b/Game/Code/Menu/UDisplay.pas
index f27320fb..b7777353 100644
--- a/Game/Code/Menu/UDisplay.pas
+++ b/Game/Code/Menu/UDisplay.pas
@@ -22,12 +22,12 @@ type
       //fade-to-black-hack
       BlackScreen: Boolean;
 
-      doFade   : Boolean;
-      canFade  : Boolean;
-      myFade   : integer;
-      lastTime : Cardinal;
-      pTexData : Pointer;
-      pTex     : array[1..2] of glUInt;
+      FadeEnabled:  Boolean;  // true if fading is enabled
+      FadeFailed: Boolean;    // true if fading is possible (enough memory, etc.)
+      FadeState: integer;     // fading state, 0 means that the fade texture must be initialized
+      LastFadeTime: Cardinal; // last fade update time
+
+      FadeTex: array[1..2] of GLuint;
 
       FPSCounter    : Cardinal;
       LastFPS       : Cardinal;
@@ -40,10 +40,11 @@ type
       NextScreen   : PMenu;
       CurrentScreen : PMenu;
 
-      //popup hack
+      //popup data
       NextScreenWithCheck: Pmenu;
       CheckOK  : Boolean;
 
+      // FIXME: Fade is set to 0 in UMain and other files but not used here anymore.
       Fade     : Real;
 
       constructor Create;
@@ -73,206 +74,173 @@ uses
 constructor TDisplay.Create;
 var
   i: integer;
-  
+  errcode: GLenum;
 begin
   inherited Create;
 
   //popup hack
   CheckOK             := False;
-  NextScreen          := NIL;
-  NextScreenWithCheck := NIL;
+  NextScreen          := nil;
+  NextScreenWithCheck := nil;
   BlackScreen         := False;
 
   // fade mod
-  myfade:=0;
-
-  if Ini.ScreenFade=1 then
-    doFade:=True
-  else
-    doFade:=False;
+  FadeState := 0;
+  FadeEnabled := (Ini.ScreenFade = 1);
+  FadeFailed:= false;
 
-  canFade:=True;
-  // generate texture for fading between screens
-  GetMem(pTexData, 512*512*4);
+  glGenTextures(2, @FadeTex);
 
-  if pTexData <> NIL then
-  for i:= 1 to 2 do
+  for i := 1 to 2 do
   begin
-  
-    glGenTextures(1, @pTex[i] );
-
-    if glGetError <> GL_NO_ERROR then
-      canFade := False;
-
-    glBindTexture(GL_TEXTURE_2D, pTex[i]);
-    if glGetError <> GL_NO_ERROR then
-      canFade := False;
-
-    glTexImage2D(GL_TEXTURE_2D, 0, 4, 512, 512, 0, GL_RGBA, GL_UNSIGNED_BYTE, pTexData);
-    if glGetError <> GL_NO_ERROR then
-      canFade := False;
-      
+    glBindTexture(GL_TEXTURE_2D, FadeTex[i]);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-    if glGetError <> GL_NO_ERROR then
-      canFade := False;
-      
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-    if glGetError <> GL_NO_ERROR then
-      canFade := False;
-  end
-  else
-  begin
-    canFade:=False;
   end;
 
-  FreeMem(pTexData);
-
   //Set LastError for OSD to No Error
   OSD_LastError := 'No Errors';
 end;
 
 destructor TDisplay.Destroy;
 begin
-  if canFade then
-    glDeleteTextures(1,@pTex);
-    
+  glDeleteTextures(2, @FadeTex);    
   inherited Destroy;
 end;
 
 function TDisplay.Draw: Boolean;
 var
-  S:    integer;
-  Col: Real;
-  myFade2: Real;
+  S: integer;
+  FadeStateSquare: Real;
   currentTime: Cardinal;
   glError: glEnum;
-  glErrorStr: String;
 begin
   Result := True;
 
-  Col := 1;
-  {if (ParamStr(1) = '-black') or (ParamStr(1) = '-fsblack') then
-    Col := 0;    }
-
-  glClearColor(Col, Col, Col , 0);
+  glClearColor(1, 1, 1 , 0);
   glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
 
-  for S := 1 to Screens do begin
+  for S := 1 to Screens do
+  begin
     ScreenAct := S;
 
-//    if Screens = 1 then ScreenX := 0;
-//    if (Screens = 2) and (S = 1) then ScreenX := -1;
-//    if (Screens = 2) and (S = 2) then ScreenX := 1;
+    //if Screens = 1 then ScreenX := 0;
+    //if (Screens = 2) and (S = 1) then ScreenX := -1;
+    //if (Screens = 2) and (S = 2) then ScreenX := 1;
     ScreenX := 0;
 
     glViewPort((S-1) * ScreenW div Screens, 0, ScreenW div Screens, ScreenH);
 
-    //popup hack
+    // popup hack
     // check was successful... move on
     if CheckOK then
     begin
-      if assigned (NextScreenWithCheck)then
+      if assigned(NextScreenWithCheck) then
       begin
-        NextScreen:=NextScreenWithCheck;
-        NextScreenWithCheck := NIL;
-        CheckOk:=False;
+        NextScreen := NextScreenWithCheck;
+        NextScreenWithCheck := nil;
+        CheckOk := False;
       end
       else
       begin
-        BlackScreen:=True; // end of game - fade to black before exit
+        // on end of game fade to black before exit
+        BlackScreen := True;
       end;
     end;
 
-//    CurrentScreen.SetAnimationProgress(1);
-    if (not assigned (NextScreen)) and (not BlackScreen) then
+    if (not assigned(NextScreen)) and (not BlackScreen) then
     begin
       CurrentScreen.Draw;
 
       //popup mod
-      if (ScreenPopupError <> NIL) and ScreenPopupError.Visible then
+      if (ScreenPopupError <> nil) and ScreenPopupError.Visible then
         ScreenPopupError.Draw
-      else if (ScreenPopupCheck <> NIL) and ScreenPopupCheck.Visible then
+      else if (ScreenPopupCheck <> nil) and ScreenPopupCheck.Visible then
         ScreenPopupCheck.Draw;
 
       // fade mod
-      myfade:=0;
-      if (Ini.ScreenFade=1) and canFade then
-        doFade:=True
-      else if Ini.ScreenFade=0 then
-        doFade:=False;
+      FadeState := 0;
+      if ((Ini.ScreenFade = 1) and (not FadeFailed)) then
+        FadeEnabled := True
+      else if (Ini.ScreenFade = 0) then
+        FadeEnabled := False;
     end
     else
     begin
-      // check if we had an initialization error (canfade=false, dofade=true)
-      if doFade and not canFade then
+      // disable fading if initialization failed
+      if (FadeEnabled and FadeFailed) then
       begin
-        doFade:=False; //disable fading
-//        ScreenPopupError.ShowPopup('Error initializing\nfade texture\n\nfading\ndisabled'); //show error message
+        FadeEnabled := False;
       end;
-      if doFade and canFade then
+      
+      if (FadeEnabled and not FadeFailed) then
       begin
-        // fade mod
         //Create Fading texture if we're just starting
-        if myfade = 0 then
+        if FadeState = 0 then
         begin
+          // resize viewport to fit texture
           glViewPort(0, 0, 512, 512);
+
+          // draw screen that will be faded
           CurrentScreen.Draw;
-          glBindTexture(GL_TEXTURE_2D, pTex[S]);
+
+          // clear OpenGL errors, otherwise fading might be disabled due to some
+          // older errors in previous OpenGL calls.
+          glGetError();
+
+          // copy screen to texture
+          glBindTexture(GL_TEXTURE_2D, FadeTex[S]);
           glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 0, 0, 512, 512, 0);
-          glError:=glGetError;
+          glError := glGetError();
           if (glError <> GL_NO_ERROR) then
           begin
-            canFade := False;
-            glErrorStr := gluErrorString(glError);
-//            ScreenPopupError.ShowPopup('Error copying\nfade texture\n('+glErrorStr+')\nfading\ndisabled'); //show error message
+            FadeFailed := true;
+            Log.LogWarn('Fading disabled: ' + gluErrorString(glError), 'TDisplay.Draw');
           end;
           glViewPort((S-1) * ScreenW div Screens, 0, ScreenW div Screens, ScreenH);
+
           // blackscreen-hack
           if not BlackScreen then
             NextScreen.onShow;
 
-          lastTime:=SDL_GetTicks();
-          if (S=2) or (Screens = 1) then
-            myfade:=myfade+1;
+          // update fade state
+          LastFadeTime := SDL_GetTicks();
+          if (S = 2) or (Screens = 1) then
+            FadeState := FadeState + 1;
         end; // end texture creation in first fading step
 
         //do some time-based fading
-        currentTime:=SDL_GetTicks();
-        if (currentTime > lastTime+30) and (S=1) then
+        currentTime := SDL_GetTicks();
+        if (currentTime > LastFadeTime+30) and (S = 1) then
         begin
-          myfade:=myfade+4;
-          lastTime:=currentTime;
+          FadeState := FadeState + 4;
+          LastFadeTime := currentTime;
         end;
 
-//      LastFade := Fade;   // whatever
-//      Fade := Fade -0.999; // start fading out
-
-
-//      CurrentScreen.ShowFinish := false; // no purpose?
-
-//      CurrentScreen.SetAnimationProgress(Fade-1); // nop?
-
         // blackscreen-hack
         if not BlackScreen then
           NextScreen.Draw // draw next screen
-        else if ScreenAct=1 then
+        else if ScreenAct = 1 then
         begin
           glClearColor(0, 0, 0 , 0);
           glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
         end;
 
-      // and draw old screen over it... slowly fading out
-        myfade2:=(myfade*myfade)/10000;
-        glBindTexture(GL_TEXTURE_2D, pTex[S]);
-        glColor4f(1, 1, 1, (1000-myfade*myfade)/1000); // strange calculation - alpha gets negative... but looks good this way
+        // and draw old screen over it... slowly fading out
+
+        FadeStateSquare := (FadeState*FadeState)/10000;
+
+        glBindTexture(GL_TEXTURE_2D, FadeTex[S]);
+        glColor4f(1, 1, 1, 1-FadeStateSquare);
+
         glEnable(GL_TEXTURE_2D);
         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
         glEnable(GL_BLEND);
         glBegin(GL_QUADS);
-          glTexCoord2f(0+myfade2,0+myfade2);glVertex2f(0,   600);
-          glTexCoord2f(0+myfade2,1-myfade2);glVertex2f(0,   0);
-          glTexCoord2f(1-myfade2,1-myfade2);glVertex2f(800, 0);
-          glTexCoord2f(1-myfade2,0+myfade2);glVertex2f(800, 600);
+          glTexCoord2f(0+FadeStateSquare, 0+FadeStateSquare); glVertex2f(0,   600);
+          glTexCoord2f(0+FadeStateSquare, 1-FadeStateSquare); glVertex2f(0,   0);
+          glTexCoord2f(1-FadeStateSquare, 1-FadeStateSquare); glVertex2f(800, 0);
+          glTexCoord2f(1-FadeStateSquare, 0+FadeStateSquare); glVertex2f(800, 600);
         glEnd;
         glDisable(GL_BLEND);
         glDisable(GL_TEXTURE_2D);
@@ -283,12 +251,13 @@ begin
         NextScreen.OnShow;
       end;
 
-      if ((myfade > 40) or (not doFade) or (not canFade)) And (S = 1) then
-      begin // fade out complete...
-        myFade:=0;
+      if ((FadeState > 40) or (not FadeEnabled) or FadeFailed) and (S = 1) then
+      begin
+        // fade out complete...
+        FadeState := 0;
         CurrentScreen.onHide;
-        CurrentScreen.ShowFinish:=False;
-        CurrentScreen:=NextScreen;
+        CurrentScreen.ShowFinish := False;
+        CurrentScreen := NextScreen;
         NextScreen := nil;
         if not blackscreen then
         begin
@@ -297,30 +266,20 @@ begin
         end
         else
         begin
-          Result:=False;
+          Result := False;
           Break;
         end;
-      // end of fade mod
       end;
     end; // if
 
     //Draw OSD only on first Screen if Debug Mode is enabled
-    if ((Ini.Debug = 1) or (Params.Debug)) and (S=1) then
-      DrawDebugInformation;
-      
+    if ((Ini.Debug = 1) or (Params.Debug)) and (S = 1) then
+      DrawDebugInformation;      
   end; // for
 
   // SDL_GL_SwapBuffers();
 end;
 
-{function TDisplay.Fade(FadeIn : Boolean; Steps : UInt8): UInt8;
-begin
-  Self.FadeIn := FadeIn;
-  FadeStep := (SizeOf(FadeStep) * $FF) div Steps;
-  ActualStep := $FF;
-  Result := $FF div FadeStep;
-end;}
-
 procedure TDisplay.SaveScreenShot;
 var
   Num:        integer;