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Diffstat (limited to 'engines/sci/engine/vm.cpp')
| -rw-r--r-- | engines/sci/engine/vm.cpp | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/engines/sci/engine/vm.cpp b/engines/sci/engine/vm.cpp index 171dfe353b..3ce0caa976 100644 --- a/engines/sci/engine/vm.cpp +++ b/engines/sci/engine/vm.cpp @@ -896,6 +896,17 @@ void run_vm(EngineState *s, int restoring) { case op_uge_: // 0x14 (20) s->r_prev = s->r_acc; r_temp = POP32(); + + // SCI0/SCI1 scripts use this to check whether a + // parameter is a pointer or a far text + // reference. It is used e.g. by the standard library + // Print function to distinguish two ways of calling it: + // + // (Print "foo") // Pointer to a string + // (Print 420 5) // Reference to the fifth message in text resource 420 + + // It works because in those games, the maximum resource number is 999, + // so any parameter value above that threshold must be a pointer. if (s->r_acc == make_reg(0, 0x3e8)) s->r_acc = make_reg(0, r_temp.segment); else if (r_temp.segment && s->r_acc.segment) @@ -907,6 +918,8 @@ void run_vm(EngineState *s, int restoring) { case op_ult_: // 0x15 (21) s->r_prev = s->r_acc; r_temp = POP32(); + + // See above if (s->r_acc == make_reg(0, 0x3e8)) s->r_acc = make_reg(0, !r_temp.segment); else if (r_temp.segment && s->r_acc.segment) |