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Cleaned out a bunch of code duplication.
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@icculus
icculus committed Aug 26, 2015
1 parent 0a5423d commit deef544
Showing 1 changed file with 68 additions and 159 deletions.
227 changes: 68 additions & 159 deletions mojozork.c
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Expand Up @@ -502,7 +502,6 @@ static void opcode_store(void)
WRITEUI16(store, src);
} // opcode_store


static uint8 *getObjectPtr(const uint16 objid)
{
if (objid == 0)
Expand Down Expand Up @@ -582,30 +581,32 @@ static uint8 *getObjectPtrParent(uint8 *objptr)
} // else
} // getGetObjectPtrParent

static void unparentObject(const uint16 objid)
{
uint8 *objptr = getObjectPtr(objid);
uint8 *parentptr = getObjectPtrParent(objptr);
if (parentptr != NULL) // if NULL, no need to remove it.
{
uint8 *ptr = parentptr + 6; // 4 to skip attrs, 2 to skip to child.
while (*ptr != objid) // if not direct child, look through sibling list...
ptr = getObjectPtr(*ptr) + 5; // get sibling field.
*ptr = *(objptr + 5); // obj sibling takes obj's place.
} // if
} // unparentObject

static void opcode_insert_obj(void)
{
const uint16 objid = GOperands[0];
const uint16 dstid = GOperands[1];

uint8 *objptr = getObjectPtr(objid);
uint8 *dstptr = getObjectPtr(dstid);
uint8 *parentptr = getObjectPtrParent(objptr);

if (GHeader.version <= 3)
{
// this child/sibling thing is messy. There's a lot of tapdancing to
// move stuff around.

// Let's take the object out of its original tree first.
if (parentptr != NULL) // if NULL, no need to remove it.
{ //p s c
uint8 *ptr = parentptr + 6; // 4 to skip attrs, 2 to skip to child.
while (*ptr != objid) // if not direct child, look through sibling list...
ptr = getObjectPtr(*ptr) + 5; // get sibling field.
*ptr = *(objptr + 5); // obj sibling takes obj's place.
} // if
unparentObject(objid); // take object out of its original tree first.

// now insert in the right place.
// now reinsert in the right place.
*(objptr + 4) = (uint8) dstid; // parent field: new destination
*(objptr + 5) = *(dstptr + 6); // sibling field: new dest's old child.
*(dstptr + 6) = objid; // dest's child field: object being moved.
Expand All @@ -619,40 +620,22 @@ static void opcode_insert_obj(void)
static void opcode_remove_obj(void)
{
const uint16 objid = GOperands[0];

uint8 *objptr = getObjectPtr(objid);
uint8 *parentptr = getObjectPtrParent(objptr);

if (GHeader.version <= 3)
if (GHeader.version > 3)
die("write me"); // fields are different in ver4+.
else
{
// this child/sibling thing is messy. There's a lot of tapdancing to
// move stuff around.

// Let's take the object out of its original tree.
if (parentptr != NULL) // if NULL, no need to remove it.
{
uint8 *ptr = parentptr + 6; // 4 to skip attrs, 2 to skip to child.
while (*ptr != objid) // if not direct child, look through sibling list...
ptr = getObjectPtr(*ptr) + 5; // get sibling field.
*ptr = *(objptr + 5); // obj sibling takes obj's place.
} // if
unparentObject(objid); // take object out of its original tree first.

// now clear out object's relationships...
*(objptr + 4) = 0; // parent field: zero.
*(objptr + 5) = 0; // sibling field: zero.
} // if
else
{
die("write me"); // fields are different in ver4+.
} // else
} // opcode_remove_obj

static void opcode_put_prop(void)
static uint8 *getObjectProperty(const uint16 objid, const uint32 propid, uint8 *_size)
{
const uint16 objid = GOperands[0];
const uint16 propid = GOperands[1];
const uint16 value = GOperands[2];

uint8 *ptr = getObjectPtr(objid);

if (GHeader.version <= 3)
Expand All @@ -667,19 +650,16 @@ static void opcode_put_prop(void)
const uint16 num = (info & 0x1F); // 5 bits for the prop id.
const uint8 size = ((info >> 5) & 0x7) + 1; // 3 bits for prop size.
// these go in descending numeric order, and should fail
// the interpreter if missing.
if (num < propid)
die("put_prop on missing object property (obj=%X, prop=%X, val=%x)", (unsigned int) objid, (unsigned int) propid, (unsigned int) value);
else if (num == propid) // found it?
// the interpreter if missing. We use 0xFFFFFFFF internally to mean "first property".
if ((num == propid) || (propid == 0xFFFFFFFF)) // found it?
{
if (size == 1)
*ptr = (value & 0xFF);
else
{
WRITEUI16(ptr, value);
} // else
return;
} // else if
if (_size)
*_size = size;
return ptr;
} // if

else if (num < propid) // we're past it.
break;

ptr += size; // try the next property.
} // while
Expand All @@ -688,6 +668,26 @@ static void opcode_put_prop(void)
{
die("write me");
} // else

return NULL;
} // getObjectProperty

static void opcode_put_prop(void)
{
const uint16 objid = GOperands[0];
const uint16 propid = GOperands[1];
const uint16 value = GOperands[2];
uint8 size = 0;
uint8 *ptr = getObjectProperty(objid, propid, &size);

if (!ptr)
die("Lookup on missing object property (obj=%X, prop=%X)", (unsigned int) objid, (unsigned int) propid);
else if (size == 1)
*ptr = (value & 0xFF);
else
{
WRITEUI16(ptr, value);
} // else
} // opcode_put_prop

static uint16 getDefaultObjectProperty(const uint16 propid)
Expand All @@ -711,101 +711,42 @@ static void opcode_get_prop(void)
const uint16 objid = GOperands[0];
const uint16 propid = GOperands[1];
uint16 result = 0;
uint8 size = 0;
uint8 *ptr = getObjectProperty(objid, propid, &size);

uint8 *ptr = getObjectPtr(objid);

if (GHeader.version <= 3)
{
ptr += 7; // skip to properties address field.
const uint16 addr = READUI16(ptr);
ptr = GStory + addr;
ptr += (*ptr * 2) + 1; // skip object name to start of properties.
while (1)
{
const uint8 info = *(ptr++);
const uint16 num = (info & 0x1F); // 5 bits for the prop id.
const uint8 size = ((info >> 5) & 0x7) + 1; // 3 bits for prop size.
// these go in descending numeric order
if (num < propid) // missing for this object? Use the default.
{
result = getDefaultObjectProperty(propid);
break;
} // if
else if (num == propid) // found it?
{
if (size == 1)
result = *ptr;
else
{
result = READUI16(ptr);
} // else
break;
} // else if

ptr += size; // try the next property.
} // while
} // if
if (!ptr)
result = getDefaultObjectProperty(propid);
else if (size == 1)
result = *ptr;
else
{
die("write me");
result = READUI16(ptr);
} // else

WRITEUI16(store, result);
} // opcode_get_prop

static void opcode_get_prop_addr(void)
{
FIXME("So much code dupe");
uint8 *store = varAddress(*(GPC++), 1);
const uint16 objid = GOperands[0];
const uint16 propid = GOperands[1];
uint16 result = 0;

uint8 *ptr = getObjectPtr(objid);

if (GHeader.version <= 3)
{
ptr += 7; // skip to properties address field.
const uint16 addr = READUI16(ptr);
ptr = GStory + addr;
ptr += (*ptr * 2) + 1; // skip object name to start of properties.
while (1)
{
const uint8 info = *(ptr++);
const uint16 num = (info & 0x1F); // 5 bits for the prop id.
const uint8 size = ((info >> 5) & 0x7) + 1; // 3 bits for prop size.
// these go in descending numeric order
if (num < propid) // missing for this object?
break;
else if (num == propid) // found it?
{
result = (uint16) (ptr - GStory);
break;
} // else if

ptr += size; // try the next property.
} // while
} // if
else
{
die("write me");
} // else

uint8 *ptr = getObjectProperty(objid, propid, NULL);
const uint16 result = ptr ? ((uint16) (ptr-GStory)) : 0;
WRITEUI16(store, result);
} // opcode_get_prop_addr

static void opcode_get_prop_len(void)
{
uint8 *store = varAddress(*(GPC++), 1);
const uint8 *ptr = GStory + GOperands[0];
uint16 result = 0;
uint16 result;

if (GOperands[0] == 0)
result = 0; // this must return 0, to avoid a bug in older Infocom games.
else if (GHeader.version <= 3)
{
ptr--; // go back to size field.
const uint8 info = *ptr;
const uint8 *ptr = GStory + GOperands[0];
const uint8 info = ptr[-1]; // the size field.
result = ((info >> 5) & 0x7) + 1; // 3 bits for prop size.
} // if
else
Expand All @@ -818,46 +759,19 @@ static void opcode_get_prop_len(void)

static void opcode_get_next_prop(void)
{
FIXME("So much code dupe");
uint8 *store = varAddress(*(GPC++), 1);
const uint16 objid = GOperands[0];
const uint16 propid = GOperands[1];
int thisone = (propid == 0); // zero == "first property in the list"
const int firstProp = (GOperands[1] == 0);
uint16 result = 0;
uint8 size = 0;
uint8 *ptr = getObjectProperty(objid, firstProp ? 0xFFFFFFFF : GOperands[1], &size);

uint8 *ptr = getObjectPtr(objid);

if (GHeader.version <= 3)
{
ptr += 7; // skip to properties address field.
const uint16 addr = READUI16(ptr);
ptr = GStory + addr;
ptr += (*ptr * 2) + 1; // skip object name to start of properties.
while (1)
{
const uint8 info = *(ptr++);
const uint16 num = (info & 0x1F); // 5 bits for the prop id.
const uint8 size = ((info >> 5) & 0x7) + 1; // 3 bits for prop size.
// these go in descending numeric order
if (thisone)
{
result = num;
break;
} // if

else if (num < propid) // missing for this object?
die("get_next_prop on missing propery");

else if (num == propid) // found it?
thisone = 1;

ptr += size; // try the next property.
} // while
} // if
if (!ptr)
die("get_next_prop on missing property obj=%X, prop=%X", (unsigned int) objid, (unsigned int) GOperands[1]);
else if (GHeader.version <= 3)
result = ptr[firstProp ? -1 : ((sint8) size)] & 0x1F; // 5 bits for the prop id.
else
{
die("write me");
} // else

WRITEUI16(store, result);
} // opcode_get_next_prop
Expand All @@ -871,9 +785,7 @@ static void opcode_jin(void)
if (GHeader.version <= 3)
doBranch((((uint16) objptr[4]) == parentid) ? 1 : 0);
else
{
die("write me"); // fields are different in ver4+.
} // else
} // opcode_jin

static uint16 getObjectRelationship(const uint16 objid, const uint8 relationship)
Expand All @@ -883,9 +795,7 @@ static uint16 getObjectRelationship(const uint16 objid, const uint8 relationship
if (GHeader.version <= 3)
return objptr[relationship];
else
{
die("write me"); // fields are different in ver4+.
} // else
} // getObjectRelationship

static void opcode_get_parent(void)
Expand Down Expand Up @@ -1894,7 +1804,6 @@ static void loadStory(const char *fname)
GSP = GStack;
} // loadStory


int main(int argc, char **argv)
{
const char *fname = (argc >= 2) ? argv[1] : "zork1.dat";
Expand Down

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