SCI32: Implement kCelLink

kCelLink exists in SSCI since 2.1mid, but it is only known to be
used in Lighthouse, during the weapon creation puzzle near the end
of the game.

3 files changed, 31 insertions, 1 deletions

diff --git a/engines/sci/engine/kernel.h b/engines/sci/engine/kernel.h
index d1dce37e48..baa891650e 100644
--- a/engines/sci/engine/kernel.h
+++ b/engines/sci/engine/kernel.h
@@ -636,6 +636,9 @@ reg_t kCelInfo(EngineState *s, int argc, reg_t *argv);
 reg_t kCelInfoGetOriginX(EngineState *s, int argc, reg_t *argv);
 reg_t kCelInfoGetOriginY(EngineState *s, int argc, reg_t *argv);
 reg_t kCelInfoGetPixel(EngineState *s, int argc, reg_t *argv);
+reg_t kCelLink(EngineState *s, int argc, reg_t *argv);
+reg_t kCelLinkGetX(EngineState *s, int argc, reg_t *argv);
+reg_t kCelLinkGetY(EngineState *s, int argc, reg_t *argv);
 
 reg_t kSetLanguage(EngineState *s, int argc, reg_t *argv);
 reg_t kScrollWindow(EngineState *s, int argc, reg_t *argv);
diff --git a/engines/sci/engine/kernel_tables.h b/engines/sci/engine/kernel_tables.h
index c65356470a..ac932199d3 100644
--- a/engines/sci/engine/kernel_tables.h
+++ b/engines/sci/engine/kernel_tables.h
@@ -575,6 +575,16 @@ static const SciKernelMapSubEntry kCelInfo_subops[] = {
 };
 
 //    version,         subId, function-mapping,                    signature,              workarounds
+static const SciKernelMapSubEntry kCelLink_subops[] = {
+	{ SIG_SINCE_SCI21MID,  0, MAP_DUMMY(CelLink0),                 "",                     NULL },
+	{ SIG_SINCE_SCI21MID,  1, MAP_DUMMY(CelLink1),                 "",                     NULL },
+	{ SIG_SINCE_SCI21MID,  2, MAP_CALL(CelLinkGetX),               "iiii",                 NULL },
+	{ SIG_SINCE_SCI21MID,  3, MAP_CALL(CelLinkGetY),               "iiii",                 NULL },
+	{ SIG_SINCE_SCI21MID,  4, MAP_DUMMY(CelLink4),                 "",                     NULL },
+	SCI_SUBOPENTRY_TERMINATOR
+};
+
+//    version,         subId, function-mapping,                    signature,              workarounds
 static const SciKernelMapSubEntry kScrollWindow_subops[] = {
 	{ SIG_SCI32,           0, MAP_CALL(ScrollWindowCreate),        "oi",                   NULL },
 	{ SIG_SCI32,           1, MAP_CALL(ScrollWindowAdd),           "iriii(i)",             kScrollWindowAdd_workarounds },
@@ -988,7 +998,7 @@ static SciKernelMapEntry s_kernelMap[] = {
 	{ MAP_DUMMY(FindClass),         SIG_EVERYWHERE,           "(.*)",                 NULL,            NULL },
 	{ MAP_DUMMY(CelRect),           SIG_EVERYWHERE,           "(.*)",                 NULL,            NULL },
 	{ MAP_DUMMY(BaseLineSpan),      SIG_EVERYWHERE,           "(.*)",                 NULL,            NULL },
-	{ MAP_DUMMY(CelLink),           SIG_EVERYWHERE,           "(.*)",                 NULL,            NULL },
+	{ MAP_CALL(CelLink),            SIG_SINCE_SCI21MID, SIGFOR_ALL, "(.*)",           kCelLink_subops, NULL },
 	{ MAP_DUMMY(AddPolygon),        SIG_EVERYWHERE,           "(.*)",                 NULL,            NULL },
 	{ MAP_DUMMY(DeletePolygon),     SIG_EVERYWHERE,           "(.*)",                 NULL,            NULL },
 	{ MAP_DUMMY(UpdatePolygon),     SIG_EVERYWHERE,           "(.*)",                 NULL,            NULL },
diff --git a/engines/sci/engine/kgraphics32.cpp b/engines/sci/engine/kgraphics32.cpp
index 44a3517458..c07282f53e 100644
--- a/engines/sci/engine/kgraphics32.cpp
+++ b/engines/sci/engine/kgraphics32.cpp
@@ -449,6 +449,23 @@ reg_t kCelInfoGetPixel(EngineState *s, int argc, reg_t *argv) {
 	return make_reg(0, view.readPixel(argv[3].toSint16(), argv[4].toSint16(), view._mirrorX));
 }
 
+// Used by Lighthouse, room 800, script 16, when in the weapon-building puzzle
+reg_t kCelLink(EngineState *s, int argc, reg_t *argv) {
+	if (!s)
+		return make_reg(0, getSciVersion());
+	error("not supposed to call this");
+}
+
+reg_t kCelLinkGetX(EngineState *s, int argc, reg_t *argv) {
+	CelObjView view(argv[0].toUint16(), argv[1].toSint16(), argv[2].toSint16());
+	return make_reg(0, view.getLinkPosition(argv[3].toSint16()).x);
+}
+
+reg_t kCelLinkGetY(EngineState *s, int argc, reg_t *argv) {
+	CelObjView view(argv[0].toUint16(), argv[1].toSint16(), argv[2].toSint16());
+	return make_reg(0, view.getLinkPosition(argv[3].toSint16()).y);
+}
+
 reg_t kScrollWindow(EngineState *s, int argc, reg_t *argv) {
 	if (!s)
 		return make_reg(0, getSciVersion());