libretro/scummvm
1
0
Fork 0
mirror of https://github.com/libretro/scummvm.git synced 2024-12-12 12:09:15 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

SCI: implement detection for uninitialized temp variable reads and implement direct fixes for them, i couldnt figure out a valid replacement for island, pharkas and laurabow2 work that way. this should also get changed to a replacement table

Browse Source 
svn-id: r50211
This commit is contained in:
Martin Kiewitz 2010-06-24 11:54:33 +00:00
parent 0722d96a3e
commit f93ca1e424
2 changed files with 39 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
engines/sci/engine/kgraphics.cpp
View File

@ -351,7 +351,7 @@ reg_t kTextSize(EngineState *s, int argc, reg_t *argv) {
}
textWidth = dest[3].toUint16(); textHeight = dest[2].toUint16();
#ifdef ENABLE_SCI32
if (!g_sci->_gfxText16) {
// TODO: Implement this
@ -1041,6 +1041,7 @@ reg_t kDrawCel(EngineState *s, int argc, reg_t *argv) {
bool hiresMode = (argc > 7) ? true : false;
reg_t upscaledHiresHandle = (argc > 7) ? argv[7] : NULL_REG;
#if 0
if (g_sci->getGameId() == "freddypharkas") {
// WORKAROUND
// Script 24 contains code that draws the game menu on screen. It uses a temp variable for setting priority that
@ -1058,6 +1059,7 @@ reg_t kDrawCel(EngineState *s, int argc, reg_t *argv) {
if ((viewId == 995) && (priority == 0))
priority = 15;
}
#endif
g_sci->_gfxPaint16->kernelDrawCel(viewId, loopNo, celNo, x, y, priority, paletteNo, hiresMode, upscaledHiresHandle);

49
engines/sci/engine/vm.cpp
View File

@ -184,9 +184,28 @@ static bool validate_variable(reg_t *r, reg_t *stack_base, int type, int max, in
}
static reg_t validate_read_var(reg_t *r, reg_t *stack_base, int type, int max, int index, int line, reg_t default_value) {
if (validate_variable(r, stack_base, type, max, index, line))
if (validate_variable(r, stack_base, type, max, index, line)) {
if (type == VAR_TEMP && r[index].segment == 0xffff) {
// Uninitialized read on a temp
// We need to find correct replacements for each situation manually
// FIXME: this should use a table which contains workarounds for gameId, scriptnumber and temp index and
// a replacement value
Script *local_script = g_sci->getEngineState()->_segMan->getScriptIfLoaded(g_sci->getEngineState()->xs->local_segment);
int currentScriptNr = local_script->_nr;
warning("uninitialized read for temp %d, script %d", index, currentScriptNr);
Common::String gameId = g_sci->getGameId();
if ((gameId == "laurabow2") && (currentScriptNr == 24) && (index == 5))
return make_reg(0, 0xf); // priority replacement for menu
if ((gameId == "freddypharkas") && (currentScriptNr == 24) && (index == 5))
return make_reg(0, 0xf); // priority replacement for menu
if ((gameId == "islandbrain") && (currentScriptNr == 140) && (index == 3)) {
r[index] = make_reg(0, 255);
return r[index];
}
error("uninitialized read!");
}
return r[index];
else
} else
return default_value;
}
@ -763,9 +782,6 @@ void run_vm(EngineState *s, bool restoring) {
int old_executionStackBase = s->executionStackBase;
// Used to detect the stack bottom, for "physical" returns
const byte *code_buf = NULL; // (Avoid spurious warning)
// Used for a workaround in op_link below, in order to avoid string matching (which can
// be slow if used in the game script interpreter)
bool isIslandOfDrBrain = (g_sci->getGameId() == "islandbrain");
if (!local_script) {
error("run_vm(): program counter gone astray (local_script pointer is null)");
@ -1137,14 +1153,21 @@ void run_vm(EngineState *s, bool restoring) {
break;
case op_link: // 0x1f (31)
if (local_script->_nr == 140 && isIslandOfDrBrain) {
// WORKAROUND for The Island of Dr. Brain, room 140.
// Script 140 runs in an endless loop if we set its
// variables to 0 here.
} else {
for (int i = 0; i < opparams[0]; i++)
s->xs->sp[i] = NULL_REG;
}
// We shouldn't initialize temp variables at all
// We put special segment 0xFFFF in there, so that uninitialized reads can get detected
for (int i = 0; i < opparams[0]; i++)
s->xs->sp[i] = make_reg(0xffff, 0xffff);
// for (int i = 0; i < opparams[0]; i++)
// s->xs->sp[i] = make_reg(0, 'ss');
//if (local_script->_nr == 140 && isIslandOfDrBrain) {
// // WORKAROUND for The Island of Dr. Brain, room 140.
// // Script 140 runs in an endless loop if we set its
// // variables to 0 here.
//} else {
// for (int i = 0; i < opparams[0]; i++)
// s->xs->sp[i] = NULL_REG;
//}
s->xs->sp += opparams[0];
break;