changed encoding of segment 3 opcodes (increasing the number of opcodes, while reducing the width of the argument)

apps/openmw/mwscript/docs/vmformat.txt

@@ -14,7 +14,7 @@ opcodes 0x200-0x3ff unused
 
 Segment 3:
 (not implemented yet)
-opcodes 0x200-0x3ff unused
+opcodes 0x20000-0x3ffff unused
 
 Segment 4:
 (not implemented yet)

components/compiler/generator.cpp

@@ -505,6 +505,11 @@ namespace Compiler
         void message (CodeContainer& code, Literals& literals, const std::string& message,
             int buttons)
         {
+            assert (buttons>=0);
+
+            if (buttons>=256)
+                throw std::runtime_error ("A message box can't have more than 255 buttons");
+
             int index = literals.addString (message);
 
             opPushInt (code, index);

components/compiler/generator.hpp

@@ -36,8 +36,8 @@ namespace Compiler
 
         inline Interpreter::Type_Code segment3 (unsigned int c, unsigned int arg0)
         {
-            assert (c<1024);
-            return 0xc0000000 | (c<<20) | (arg0 & 0xffff);    
+            assert (c<262144);
+            return 0xc0000000 | (c<<8) | (arg0 & 0xff);
         }
 
         inline Interpreter::Type_Code segment4 (unsigned int c, unsigned int arg0,
@@ -120,4 +120,3 @@ namespace Compiler
 }
 
 #endif
-

components/interpreter/docs/vmformat.txt

@@ -19,7 +19,7 @@ Code bit-patterns:
 00ccccccAAAAAAAAAAAAAAAAAAAAAAAA segment 0: 64 opcodes, 1 24-bit argument
 01ccccccAAAAAAAAAAAABBBBBBBBBBBB segment 1: 64 opcodes, 2 12-bit arguments
 10ccccccccccAAAAAAAAAAAAAAAAAAAA segment 2: 1024 opcodes, 1 20-bit argument
-110000ccccccccccAAAAAAAAAAAAAAAA segment 3: 1024 opcodes, 1 16-bit argument
+110000ccccccccccccccccccAAAAAAAA segment 3: 262144 opcodes, 1 8-bit argument
 110001ccccccccccAAAAAAAABBBBBBBB segment 4: 1024 opcodes, 2 8-bit arguments
 110010cccccccccccccccccccccccccc segment 5: 67108864 opcodes, no arguments
 other bit-patterns reserved
@@ -50,8 +50,8 @@ op    0: show message box with message string literal index in stack[0];
          additional arguments (if any) in stack[arg0+n]..stack[arg0+1];
          n is determined according to the message string
          all arguments are removed from stack
-opcodes 1-511 unused
-opcodes 512-1023 reserved for extensions
+opcodes 1-131071 unused
+opcodes 131072-262143 reserved for extensions
 
 Segment 4:
 opcodes 0-511 unused

components/interpreter/interpreter.cpp

@@ -69,8 +69,8 @@ namespace Interpreter
         {
             case 0x30:
             {
-                int opcode = (code>>16) & 0x3ff;
-                unsigned int arg0 = code & 0xffff;
+                int opcode = (code>>8) & 0x3ffff;
+                unsigned int arg0 = code & 0xff;
 
                 std::map<int, Opcode1 *>::iterator iter = mSegment3.find (opcode);