SCI32: Implement basic kMessageBox

This kernel call seems only to be used by KQ7 1.51 (which was
Windows-only) to send warnings to the user.

It was easy enough to do a basic implementation in the ScummVM
GUI rather than just make it an empty call, so now it is a thing.

3 files changed, 7 insertions, 0 deletions

diff --git a/engines/sci/engine/kernel.h b/engines/sci/engine/kernel.h
index 6604387254..b269e9789d 100644
--- a/engines/sci/engine/kernel.h
+++ b/engines/sci/engine/kernel.h
@@ -566,6 +566,7 @@ reg_t kMoveToFront(EngineState *s, int argc, reg_t *argv);
 reg_t kMoveToEnd(EngineState *s, int argc, reg_t *argv);
 reg_t kGetWindowsOption(EngineState *s, int argc, reg_t *argv);
 reg_t kWinHelp(EngineState *s, int argc, reg_t *argv);
+reg_t kMessageBox(EngineState *s, int argc, reg_t *argv);
 reg_t kGetConfig(EngineState *s, int argc, reg_t *argv);
 reg_t kGetSierraProfileInt(EngineState *s, int argc, reg_t *argv);
 reg_t kCelInfo(EngineState *s, int argc, reg_t *argv);
diff --git a/engines/sci/engine/kernel_tables.h b/engines/sci/engine/kernel_tables.h
index 03e56ea559..19bee359c5 100644
--- a/engines/sci/engine/kernel_tables.h
+++ b/engines/sci/engine/kernel_tables.h
@@ -728,6 +728,8 @@ static SciKernelMapEntry s_kernelMap[] = {
 	{ MAP_CALL(ListEachElementDo), SIG_EVERYWHERE,           "li(.*)",                NULL,            NULL },
 	{ MAP_CALL(ListFirstTrue),     SIG_EVERYWHERE,           "li(.*)",                NULL,            NULL },
 	{ MAP_CALL(ListIndexOf),       SIG_EVERYWHERE,           "l[o0]",                 NULL,            NULL },
+	// kMessageBox is used only by KQ7 1.51
+	{ MAP_CALL(MessageBox),        SIG_SCI32, SIGFOR_ALL,    "rri",                   NULL,            NULL },
 	{ "OnMe", kIsOnMe,             SIG_EVERYWHERE,           "iioi",                  NULL,            NULL },
 	// Purge is used by the memory manager in SSCI to ensure that X number of bytes (the so called "unmovable
 	// memory") are available when the current room changes. This is similar to the SCI0-SCI1.1 FlushResources
diff --git a/engines/sci/engine/kgraphics32.cpp b/engines/sci/engine/kgraphics32.cpp
index f8ec96c843..4083414724 100644
--- a/engines/sci/engine/kgraphics32.cpp
+++ b/engines/sci/engine/kgraphics32.cpp
@@ -254,6 +254,10 @@ reg_t kWinHelp(EngineState *s, int argc, reg_t *argv) {
 	return s->r_acc;
 }
 
+reg_t kMessageBox(EngineState *s, int argc, reg_t *argv) {
+	return g_sci->_gfxControls32->kernelMessageBox(s->_segMan->getString(argv[0]), s->_segMan->getString(argv[1]), argv[2].toUint16());
+}
+
 /**
  * Causes an immediate plane transition with an optional transition
  * effect