libretro/snes9x
1
0
Fork 0
mirror of https://github.com/libretro/snes9x.git synced 2024-11-27 10:30:31 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Prevent read_idx from overflowing

Browse Source
This commit is contained in:
OV2 2018-08-25 20:08:36 +02:00
parent 7498a1aa4a
commit f139bf704f
1 changed files with 27 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
controls.cpp
View File

@ -3085,6 +3085,16 @@ void S9xSetJoypadLatch (bool latch)
FLAG_LATCH = latch; FLAG_LATCH = latch;
} }
// prevent read_idx from overflowing (only latching resets it)
// otherwise $4016/7 reads will start returning input data again
static inline uint8 IncreaseReadIdxPost(uint8 &var)
{
uint8 oldval = var;
if (var < 255)
var++;
return oldval;
}
uint8 S9xReadJOYSERn (int n) uint8 S9xReadJOYSERn (int n)
{ {
int i, j, r; int i, j, r;
@ -3139,7 +3149,7 @@ uint8 S9xReadJOYSERn (int n)
switch (i = curcontrollers[n]) switch (i = curcontrollers[n])
{ {
case MP5: case MP5:
r = read_idx[n][FLAG_IOBIT(n) ? 0 : 1]++; r = IncreaseReadIdxPost(read_idx[n][FLAG_IOBIT(n) ? 0 : 1]);
j = FLAG_IOBIT(n) ? 0 : 2; j = FLAG_IOBIT(n) ? 0 : 2;
for (i = 0; i < 2; i++, j++) for (i = 0; i < 2; i++, j++)
@ -3164,64 +3174,64 @@ uint8 S9xReadJOYSERn (int n)
case JOYPAD7: case JOYPAD7:
if (read_idx[n][0] >= 16) if (read_idx[n][0] >= 16)
{ {
read_idx[n][0]++; IncreaseReadIdxPost(read_idx[n][0]);
return (bits | 1); return (bits | 1);
} }
else else
return (bits | ((joypad[i - JOYPAD0].buttons & (0x8000 >> read_idx[n][0]++)) ? 1 : 0)); return (bits | ((joypad[i - JOYPAD0].buttons & (0x8000 >> IncreaseReadIdxPost(read_idx[n][0]))) ? 1 : 0));
case MOUSE0: case MOUSE0:
case MOUSE1: case MOUSE1:
if (read_idx[n][0] < 8) if (read_idx[n][0] < 8)
{ {
read_idx[n][0]++; IncreaseReadIdxPost(read_idx[n][0]);
return (bits); return (bits);
} }
else else
if (read_idx[n][0] < 16) if (read_idx[n][0] < 16)
return (bits | ((mouse[i - MOUSE0].buttons & (0x8000 >> read_idx[n][0]++)) ? 1 : 0)); return (bits | ((mouse[i - MOUSE0].buttons & (0x8000 >> IncreaseReadIdxPost(read_idx[n][0]))) ? 1 : 0));
else else
if (read_idx[n][0] < 24) if (read_idx[n][0] < 24)
return (bits | ((mouse[i - MOUSE0].delta_y & (0x800000 >> read_idx[n][0]++)) ? 1 : 0)); return (bits | ((mouse[i - MOUSE0].delta_y & (0x800000 >> IncreaseReadIdxPost(read_idx[n][0]))) ? 1 : 0));
else else
if (read_idx[n][0] < 32) if (read_idx[n][0] < 32)
return (bits | ((mouse[i - MOUSE0].delta_x & (0x80000000 >> read_idx[n][0]++)) ? 1 : 0)); return (bits | ((mouse[i - MOUSE0].delta_x & (0x80000000 >> IncreaseReadIdxPost(read_idx[n][0]))) ? 1 : 0));
else else
{ {
read_idx[n][0]++; IncreaseReadIdxPost(read_idx[n][0]);
return (bits | 1); return (bits | 1);
} }
case SUPERSCOPE: case SUPERSCOPE:
if (read_idx[n][0] < 8) if (read_idx[n][0] < 8)
return (bits | ((superscope.read_buttons & (0x80 >> read_idx[n][0]++)) ? 1 : 0)); return (bits | ((superscope.read_buttons & (0x80 >> IncreaseReadIdxPost(read_idx[n][0]))) ? 1 : 0));
else else
{ {
read_idx[n][0]++; IncreaseReadIdxPost(read_idx[n][0]);
return (bits | 1); return (bits | 1);
} }
case ONE_JUSTIFIER: case ONE_JUSTIFIER:
if (read_idx[n][0] < 24) if (read_idx[n][0] < 24)
return (bits | ((0xaa7000 >> read_idx[n][0]++) & 1)); return (bits | ((0xaa7000 >> IncreaseReadIdxPost(read_idx[n][0])) & 1));
else else
if (read_idx[n][0] < 32) if (read_idx[n][0] < 32)
return (bits | ((justifier.buttons & (JUSTIFIER_TRIGGER | JUSTIFIER_START | JUSTIFIER_SELECT) & (0x80000000 >> read_idx[n][0]++)) ? 1 : 0)); return (bits | ((justifier.buttons & (JUSTIFIER_TRIGGER | JUSTIFIER_START | JUSTIFIER_SELECT) & (0x80000000 >> IncreaseReadIdxPost(read_idx[n][0]))) ? 1 : 0));
else else
{ {
read_idx[n][0]++; IncreaseReadIdxPost(read_idx[n][0]);
return (bits | 1); return (bits | 1);
} }
case TWO_JUSTIFIERS: case TWO_JUSTIFIERS:
if (read_idx[n][0] < 24) if (read_idx[n][0] < 24)
return (bits | ((0xaa7000 >> read_idx[n][0]++) & 1)); return (bits | ((0xaa7000 >> IncreaseReadIdxPost(read_idx[n][0])) & 1));
else else
if (read_idx[n][0] < 32) if (read_idx[n][0] < 32)
return (bits | ((justifier.buttons & (0x80000000 >> read_idx[n][0]++)) ? 1 : 0)); return (bits | ((justifier.buttons & (0x80000000 >> IncreaseReadIdxPost(read_idx[n][0]))) ? 1 : 0));
else else
{ {
read_idx[n][0]++; IncreaseReadIdxPost(read_idx[n][0]);
return (bits | 1); return (bits | 1);
} }
@ -3230,7 +3240,7 @@ uint8 S9xReadJOYSERn (int n)
return (bits | ((macsrifle.buttons & 0x01) ? 1 : 0)); return (bits | ((macsrifle.buttons & 0x01) ? 1 : 0));
default: default:
read_idx[n][0]++; IncreaseReadIdxPost(read_idx[n][0]);
return (bits); return (bits);
} }
} }