5 files changed, 58 insertions, 20 deletions

diff --git a/engines/sci/engine/kernel.h b/engines/sci/engine/kernel.h
index 4208ae348f..90f582c291 100644
--- a/engines/sci/engine/kernel.h
+++ b/engines/sci/engine/kernel.h
@@ -610,6 +610,8 @@ reg_t kSave(EngineState *s, int argc, reg_t *argv);
 reg_t kAutoSave(EngineState *s, int argc, reg_t *argv);
 reg_t kList(EngineState *s, int argc, reg_t *argv);
 reg_t kCD(EngineState *s, int argc, reg_t *argv);
+reg_t kCheckCD(EngineState *s, int argc, reg_t *argv);
+reg_t kGetSavedCD(EngineState *s, int argc, reg_t *argv);
 reg_t kAddPicAt(EngineState *s, int argc, reg_t *argv);
 reg_t kAddBefore(EngineState *s, int argc, reg_t *argv);
 reg_t kMoveToFront(EngineState *s, int argc, reg_t *argv);
diff --git a/engines/sci/engine/kernel_tables.h b/engines/sci/engine/kernel_tables.h
index 3e048277c1..73861753d0 100644
--- a/engines/sci/engine/kernel_tables.h
+++ b/engines/sci/engine/kernel_tables.h
@@ -396,6 +396,13 @@ static const SciKernelMapSubEntry kBitmap_subops[] = {
 };
 
 //    version,         subId, function-mapping,                    signature,              workarounds
+static const SciKernelMapSubEntry kCD_subops[] = {
+	{ SIG_SINCE_SCI21MID,  0, MAP_CALL(CheckCD),                   "(i)",                  NULL },
+	{ SIG_SINCE_SCI21MID,  1, MAP_CALL(GetSavedCD),                "",                     NULL },
+	SCI_SUBOPENTRY_TERMINATOR
+};
+
+//    version,         subId, function-mapping,                    signature,              workarounds
 static const SciKernelMapSubEntry kList_subops[] = {
 	{ SIG_SINCE_SCI21,     0, MAP_CALL(NewList),                   "",                     NULL },
 	{ SIG_SINCE_SCI21,     1, MAP_CALL(DisposeList),               "l",                    NULL },
@@ -871,7 +878,7 @@ static SciKernelMapEntry s_kernelMap[] = {
 	{ MAP_DUMMY(PointSize),        SIG_EVERYWHERE,           "(.*)",                  NULL,            NULL },
 
 	// SCI2.1 Kernel Functions
-	{ MAP_CALL(CD),                SIG_EVERYWHERE,           "(.*)",                  NULL,            NULL },
+	{ MAP_CALL(CD),                SIG_SINCE_SCI21MID, SIGFOR_ALL, "(.*)",            kCD_subops,      NULL },
 	{ MAP_CALL(IsOnMe),            SIG_EVERYWHERE,           "iioi",                  NULL,            NULL },
 	{ MAP_CALL(List),              SIG_SINCE_SCI21, SIGFOR_ALL, "(.*)",               kList_subops,    NULL },
 	{ MAP_CALL(MulDiv),            SIG_EVERYWHERE,           "iii",                   NULL,            NULL },
diff --git a/engines/sci/engine/kfile.cpp b/engines/sci/engine/kfile.cpp
index 3bcadd143c..a3a97eb7ee 100644
--- a/engines/sci/engine/kfile.cpp
+++ b/engines/sci/engine/kfile.cpp
@@ -40,6 +40,9 @@
 #include "sci/engine/savegame.h"
 #include "sci/sound/audio.h"
 #include "sci/console.h"
+#ifdef ENABLE_SCI32
+#include "sci/resource.h"
+#endif
 
 namespace Sci {
 
@@ -196,26 +199,25 @@ reg_t kValidPath(EngineState *s, int argc, reg_t *argv) {
 #ifdef ENABLE_SCI32
 
 reg_t kCD(EngineState *s, int argc, reg_t *argv) {
-	// TODO: Stub
-	switch (argv[0].toUint16()) {
-	case 0:
-		if (argc == 1) {
-			// Check if a disc is in the drive
-			return TRUE_REG;
-		} else {
-			// Check if the specified disc is in the drive
-			// and return the current disc number. We just
-			// return the requested disc number.
-			return argv[1];
-		}
-	case 1:
-		// Return the current CD number
-		return make_reg(0, 1);
-	default:
-		warning("CD(%d)", argv[0].toUint16());
+	if (!s)
+		return make_reg(0, getSciVersion());
+	error("not supposed to call this");
+}
+
+reg_t kCheckCD(EngineState *s, int argc, reg_t *argv) {
+	const int16 cdNo = argc > 0 ? argv[0].toSint16() : 0;
+
+	if (cdNo) {
+		g_sci->getResMan()->findDisc(cdNo);
 	}
 
-	return NULL_REG;
+	return make_reg(0, g_sci->getResMan()->getCurrentDiscNo());
+}
+
+reg_t kGetSavedCD(EngineState *s, int argc, reg_t *argv) {
+	// TODO: This is wrong, CD number needs to be available prior to
+	// the save game being loaded
+	return make_reg(0, g_sci->getResMan()->getCurrentDiscNo());
 }
 
 #endif
diff --git a/engines/sci/resource.cpp b/engines/sci/resource.cpp
index 48278e35a7..26b8a32861 100644
--- a/engines/sci/resource.cpp
+++ b/engines/sci/resource.cpp
@@ -859,6 +859,13 @@ void ResourceManager::addResourcesFromChunk(uint16 id) {
 	scanNewSources();
 }
 
+void ResourceManager::findDisc(const int16 discNo) {
+	// Since all resources are expected to be copied from the original discs
+	// into a single game directory, this call just records the number of the CD
+	// that the game has requested
+	_currentDiscNo = discNo;
+}
+
 #endif
 
 void ResourceManager::freeResourceSources() {
@@ -878,7 +885,9 @@ void ResourceManager::init() {
 	_LRU.clear();
 	_resMap.clear();
 	_audioMapSCI1 = NULL;
-
+#ifdef ENABLE_SCI32
+	_currentDiscNo = 1;
+#endif
 	// FIXME: put this in an Init() function, so that we can error out if detection fails completely
 
 	_mapVersion = detectMapVersion();
diff --git a/engines/sci/resource.h b/engines/sci/resource.h
index f70bf48bd4..49cc52399e 100644
--- a/engines/sci/resource.h
+++ b/engines/sci/resource.h
@@ -397,6 +397,24 @@ public:
 	 * resource manager.
 	 */
 	void addResourcesFromChunk(uint16 id);
+
+	/**
+	 * Updates the currently active disc number.
+	 */
+	void findDisc(const int16 discNo);
+
+	/**
+	 * Gets the currently active disc number.
+	 */
+	int16 getCurrentDiscNo() const { return _currentDiscNo; }
+
+private:
+	/**
+	 * The currently active disc number.
+	 */
+	int16 _currentDiscNo;
+
+public:
 #endif
 
 	bool detectHires();