The script engine frequently needs to pass pointers to various structures

etc. to the different opcodes. Until now it has done so by casting the
pointer to an int32 (opcode parameters are represented as arrays of int32)
and then the opcode function casts it back to whatever pointer it needs.

At least in C there is no guarantee that a pointer can be represented as an
integer type (though apparently C99 may define such a type), so this has
struck me as unsafe ever since I first noticed it.

However, since all such pointers appear to point to the memory block owned
by the memory manager, we can easily convert them to integers by treating
them as offsets into the memory block. So that's what I have done. I hope I
caught all the occurences in the opcode functions, or we're going to have
some pretty interesting regressions on our hands...

svn-id: r11241

1 files changed, 5 insertions, 5 deletions

diff --git a/sword2/build_display.cpp b/sword2/build_display.cpp
index 82f098719a..5c51ed5b32 100644
--- a/sword2/build_display.cpp
+++ b/sword2/build_display.cpp
@@ -576,7 +576,7 @@ void Sword2Engine::registerFrame(int32 *params, buildit *build_unit) {
 
 	// open animation file & set up the necessary pointers
 
-	ob_graph = (Object_graphic *) params[1];
+	ob_graph = (Object_graphic *) memory->intToPtr(params[1]);
 
 	assert(ob_graph->anim_resource);
 
@@ -614,7 +614,7 @@ void Sword2Engine::registerFrame(int32 *params, buildit *build_unit) {
 
 	if (cdt_entry->frameType & FRAME_OFFSET) {
 		// param 2 is pointer to mega structure
-		ob_mega = (Object_mega *) params[2];
+		ob_mega = (Object_mega *) memory->intToPtr(params[2]);
 
 		// calc scale at which to print the sprite, based on feet
 		// y-coord & scaling constants (NB. 'scale' is actually
@@ -655,7 +655,7 @@ void Sword2Engine::registerFrame(int32 *params, buildit *build_unit) {
 
 	if (params[0]) {
 		// passed a mouse structure, so add to the _mouseList
-		ob_mouse = (Object_mouse *) params[0];
+		ob_mouse = (Object_mouse *) memory->intToPtr(params[0]);
 
 		// only if 'pointer' isn't NULL
 		if (ob_mouse->pointer) {
@@ -706,7 +706,7 @@ int32 Logic::fnRegisterFrame(int32 *params) {
 }
 
 int32 Sword2Engine::registerFrame(int32 *params) {
-	Object_graphic *ob_graph = (Object_graphic *) params[1];
+	Object_graphic *ob_graph = (Object_graphic *) memory->intToPtr(params[1]);
 
 	// check low word for sprite type
 	switch (ob_graph->type & 0x0000ffff) {
@@ -788,7 +788,7 @@ int32 Logic::fnUpdatePlayerStats(int32 *params) {
 
 	// params:	0 pointer to mega structure
 
-	Object_mega *ob_mega = (Object_mega *) params[0];
+	Object_mega *ob_mega = (Object_mega *) memory->intToPtr(params[0]);
 
 	_vm->_thisScreen.player_feet_x = ob_mega->feet_x;
 	_vm->_thisScreen.player_feet_y = ob_mega->feet_y;