Added patch clipping callback mechanism, since Strife needs to modify

all the V_DrawPatch functions that it uses to return if the patch
overlaps the edge of or is completely outside of the framebuffer. This
could be extended to handle Final DOOM as well if it proves
satisfactory.

Subversion-branch: /branches/strife-branch
Subversion-revision: 1972

3 files changed, 82 insertions, 1 deletions

diff --git a/src/strife/d_main.c b/src/strife/d_main.c
index c888438a..1bfaad65 100644
--- a/src/strife/d_main.c
+++ b/src/strife/d_main.c
@@ -65,6 +65,7 @@
 #include "i_system.h"
 #include "i_timer.h"
 #include "i_video.h"
+#include "i_swap.h"
 
 #include "g_game.h"
 
@@ -1106,6 +1107,45 @@ static void D_Endoom(void)
     I_Endoom(endoom);
 }
 
+//=============================================================================
+//
+// haleyjd: Chocolate Strife Specifics
+//
+// None of the code in here is from the original executable, but is needed for
+// other reasons.
+
+//
+// D_PatchClipCallback
+//
+// haleyjd 08/28/10: Clip patches to the framebuffer without errors.
+// Returns false if V_DrawPatch should return without drawing.
+//
+static boolean D_PatchClipCallback(patch_t *patch, int x, int y)
+{
+    // note that offsets were already accounted for in V_DrawPatch
+    return (x >= 0 && y >= 0 
+            && x + SHORT(patch->width) <= SCREENWIDTH 
+            && y + SHORT(patch->height) <= SCREENHEIGHT);
+}
+
+//
+// D_InitChocoStrife
+//
+// haleyjd 08/28/10: Take care of some Strife-specific initialization
+// that is necessitated by Chocolate Doom issues, such as setting global 
+// callbacks.
+//
+static void D_InitChocoStrife(void)
+{
+    // set the V_DrawPatch clipping callback
+    V_SetPatchClipCallback(D_PatchClipCallback);
+}
+
+//
+// End Chocolate Strife Specifics
+//
+//=============================================================================
+
 //
 // D_DoomMain
 //
@@ -1568,7 +1608,7 @@ void D_DoomMain (void)
     SetSaveGameDir(iwadfile);
 
     // Check for -file in shareware
-    if (0 /*modifiedgame*/) // TEST
+    if (0 /*modifiedgame*/) // STRIFE-FIXME: DISABLED FOR TESTING
     {
         // These are the lumps that will be checked in IWAD,
         // if any one is not present, execution will be aborted.
@@ -1744,6 +1784,9 @@ void D_DoomMain (void)
     I_PrintStartupBanner(gamedescription);
     PrintDehackedBanners();
 
+    // haleyjd 08/28/10: Init Choco Strife stuff.
+    D_InitChocoStrife();
+
     printf (DEH_String("M_Init: Init miscellaneous info.\n"));
     M_Init ();
 
diff --git a/src/v_video.c b/src/v_video.c
index 6549a81b..b6c621ba 100644
--- a/src/v_video.c
+++ b/src/v_video.c
@@ -54,6 +54,9 @@ static byte *dest_screen = NULL;
 
 int dirtybox[4]; 
 
+// haleyjd 08/28/10: clipping callback function for patches.
+// This is needed for Chocolate Strife, which clips patches to the screen.
+static vpatchclipfunc_t patchclip_callback = NULL;
 
 //
 // V_MarkRect 
@@ -108,6 +111,20 @@ void V_CopyRect(int srcx, int srcy, byte *source,
     } 
 } 
  
+//
+// V_SetPatchClipCallback
+//
+// haleyjd 08/28/10: Added for Strife support.
+// By calling this function, you can setup runtime error checking for patch 
+// clipping. Strife never caused errors by drawing patches partway off-screen.
+// Some versions of vanilla DOOM also behaved differently than the default
+// implementation, so this could possibly be extended to those as well for
+// accurate emulation.
+//
+void V_SetPatchClipCallback(vpatchclipfunc_t func)
+{
+    patchclip_callback = func;
+}
 
 //
 // V_DrawPatch
@@ -127,6 +144,13 @@ void V_DrawPatch(int x, int y, patch_t *patch)
     y -= SHORT(patch->topoffset);
     x -= SHORT(patch->leftoffset);
 
+    // haleyjd 08/28/10: Strife needs silent error checking here.
+    if(patchclip_callback)
+    {
+        if(!patchclip_callback(patch, x, y))
+            return;
+    }
+
 #ifdef RANGECHECK
     if (x < 0
      || x + SHORT(patch->width) > SCREENWIDTH
@@ -184,6 +208,13 @@ void V_DrawPatchFlipped(int x, int y, patch_t *patch)
     y -= SHORT(patch->topoffset); 
     x -= SHORT(patch->leftoffset); 
 
+    // haleyjd 08/28/10: Strife needs silent error checking here.
+    if(patchclip_callback)
+    {
+        if(!patchclip_callback(patch, x, y))
+            return;
+    }
+
 #ifdef RANGECHECK 
     if (x < 0
      || x + SHORT(patch->width) > SCREENWIDTH
diff --git a/src/v_video.h b/src/v_video.h
index 0c722478..f7952eaa 100644
--- a/src/v_video.h
+++ b/src/v_video.h
@@ -46,6 +46,13 @@ extern int dirtybox[4];
 
 extern byte *tinttable;
 
+// haleyjd 08/28/10: implemented for Strife support
+// haleyjd 08/28/10: Patch clipping callback, implemented to support Choco
+// Strife.
+typedef boolean (*vpatchclipfunc_t)(patch_t *, int, int);
+void V_SetPatchClipCallback(vpatchclipfunc_t func);
+
+
 // Allocates buffer screens, call before R_Init.
 void V_Init (void);