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fix(motchan): Prevent undefined behavior when reading floats from motion channel packets #3648

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Merged
xezon merged 4 commits into from
Nov 9, 2026
+50 −64
Merged

fix(motchan): Prevent undefined behavior when reading floats from motion channel packets #3648

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9a25952
refactor(ww3d2): Read motion channel packet floats with std::bit_cast
CryoTheRenegade Oct 23, 2026
9507acb
refactor(ww3d2): Set motion channel quaternions from packets with a h…
CryoTheRenegade Nov 2, 2026
786a898
refactor(ww3d2): Copy motion channel vectors from packets with memcpy
CryoTheRenegade Nov 3, 2026
c480a7c
refactor(ww3d2): Take a packet array in the quaternion helper and dro…
CryoTheRenegade Nov 8, 2026
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57 changes: 25 additions & 32 deletions Generals/Code/Libraries/Source/WWVegas/WW3D2/motchan.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@
#include "WWLib/Vector.h"
#include "WWMath/wwmath.h"
#include "WWMath/quat.h"
#include <Utility/bit_adapter.h>
//#include <Windows.h>
// Static Table, for Adaptive Delta Decompressor
#define FILTER_TABLE_SIZE (256)
Expand Down Expand Up @@ -430,13 +431,7 @@ void TimeCodedMotionChannelClass::Get_Vector(float32 frame,float * setvec)

if (pidx == ((NumTimeCodes - 1) * PacketSize)) {

float32 *frm = (float32 *) &Data[pidx+1];

for (int i=0; i < VectorLen; i++) {

setvec[i] = frm[i];

}
memcpy(setvec, &Data[pidx+1], VectorLen * sizeof(float32));

return;

Expand All @@ -448,10 +443,7 @@ void TimeCodedMotionChannelClass::Get_Vector(float32 frame,float * setvec)
uint32 time = Data[p2idx];

if (time & W3D_TIMECODED_BINARY_MOVEMENT_FLAG) {
float32 *frm = (float32 *) &Data[pidx+1];
for (int i=0; i < VectorLen; i++) {
setvec[i] = frm[i];
}
memcpy(setvec, &Data[pidx+1], VectorLen * sizeof(float32));
return;
}

Expand All @@ -460,18 +452,28 @@ void TimeCodedMotionChannelClass::Get_Vector(float32 frame,float * setvec)

float32 ratio = (frame - time1) / (time2 - time1);

float32 *frame1 = (float32 *) &Data[pidx+1];
float32 *frame2 = (float32 *) &Data[p2idx+1];
const uint32* frame1 = &Data[pidx+1];
const uint32* frame2 = &Data[p2idx+1];

for (int i=0; i < VectorLen; i++) {

setvec[i] = WWMath::Lerp(frame1[i],frame2[i],ratio);
setvec[i] = WWMath::Lerp(std::bit_cast<float32>(frame1[i]),std::bit_cast<float32>(frame2[i]),ratio);

}

}


// Sets a quaternion from the four floats stored in a packet.
static void Set_Quaternion_From_Packet(Quaternion& q, const uint32 packet[4])
{
q.Set(
std::bit_cast<float32>(packet[0]),
std::bit_cast<float32>(packet[1]),
std::bit_cast<float32>(packet[2]),
std::bit_cast<float32>(packet[3]));
}

Quaternion TimeCodedMotionChannelClass::Get_QuatVector(float32 frame)
{

Expand All @@ -488,9 +490,7 @@ Quaternion TimeCodedMotionChannelClass::Get_QuatVector(float32 frame)

if (pidx == ((NumTimeCodes - 1) * PacketSize)) {

float32 *vec = (float32 *) &Data[pidx+1];

q.Set(vec[0], vec[1], vec[2], vec[3]);
Set_Quaternion_From_Packet(q, &Data[pidx+1]);

return( q );

Expand All @@ -502,10 +502,7 @@ Quaternion TimeCodedMotionChannelClass::Get_QuatVector(float32 frame)
uint32 time = Data[p2idx];

if (time & W3D_TIMECODED_BINARY_MOVEMENT_FLAG) {
// its a binary movement!
float32 *vec = (float32 *) &Data[pidx+1];

q.Set(vec[0], vec[1], vec[2], vec[3]);
Set_Quaternion_From_Packet(q, &Data[pidx+1]);

return( q );
}
Expand All @@ -515,14 +512,11 @@ Quaternion TimeCodedMotionChannelClass::Get_QuatVector(float32 frame)

float32 ratio = (frame - time1) / (time2 - time1);

float32 *frame1 = (float32 *) &Data[pidx+1];
float32 *frame2 = (float32 *) &Data[p2idx+1];

Quaternion q1(1);
Quaternion q2(1);
Quaternion q1;
Quaternion q2;

q1.Set(frame1[0], frame1[1], frame1[2], frame1[3]);
q2.Set(frame2[0], frame2[1], frame2[2], frame2[3]);
Set_Quaternion_From_Packet(q1, &Data[pidx+1]);
Set_Quaternion_From_Packet(q2, &Data[p2idx+1]);

Fast_Slerp(q, q1, q2, ratio);

Expand Down Expand Up @@ -972,7 +966,7 @@ bool AdaptiveDeltaMotionChannelClass::Load_W3D(ChunkLoadClass & cload)
void AdaptiveDeltaMotionChannelClass::decompress(uint32 frame_idx, float *outdata)
{
// Start Over from the beginning
float *base = (float *) &Data[0]; // pointer to our true know beginning values
const uint32* base = &Data[0]; // pointer to our true know beginning values

bool done = false;

Expand All @@ -982,7 +976,7 @@ void AdaptiveDeltaMotionChannelClass::decompress(uint32 frame_idx, float *outdat
pPacket+= (sizeof(float) * VectorLen); // skip non-compressed header information
pPacket+= PACKET_SIZE * vi; // skip to the appropriate packet start

float last_value = base[vi];
float last_value = std::bit_cast<float>(base[vi]);

for (uint32 frame=1; frame<=frame_idx;) {
// Frame Loop
Expand Down Expand Up @@ -1048,8 +1042,7 @@ void AdaptiveDeltaMotionChannelClass::decompress(uint32 src_idx, float *srcdata,
assert(src_idx < frame_idx);
src_idx++;

float *base = (float *) &Data[0]; // pointer to our true know beginning values
base += VectorLen; // skip header information
const uint32* base = &Data[VectorLen]; // skip header information

bool done = false;

Expand Down
57 changes: 25 additions & 32 deletions GeneralsMD/Code/Libraries/Source/WWVegas/WW3D2/motchan.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@
#include "WWLib/Vector.h"
#include "WWMath/wwmath.h"
#include "WWMath/quat.h"
#include <Utility/bit_adapter.h>
//#include <Windows.h>
// Static Table, for Adaptive Delta Decompressor
#define FILTER_TABLE_SIZE (256)
Expand Down Expand Up @@ -430,13 +431,7 @@ void TimeCodedMotionChannelClass::Get_Vector(float32 frame,float * setvec)

if (pidx == ((NumTimeCodes - 1) * PacketSize)) {

float32 *frm = (float32 *) &Data[pidx+1];

for (int i=0; i < VectorLen; i++) {

setvec[i] = frm[i];

}
memcpy(setvec, &Data[pidx+1], VectorLen * sizeof(float32));

return;

Expand All @@ -448,10 +443,7 @@ void TimeCodedMotionChannelClass::Get_Vector(float32 frame,float * setvec)
uint32 time = Data[p2idx];

if (time & W3D_TIMECODED_BINARY_MOVEMENT_FLAG) {
float32 *frm = (float32 *) &Data[pidx+1];
for (int i=0; i < VectorLen; i++) {
setvec[i] = frm[i];
}
memcpy(setvec, &Data[pidx+1], VectorLen * sizeof(float32));
return;
}

Expand All @@ -460,18 +452,28 @@ void TimeCodedMotionChannelClass::Get_Vector(float32 frame,float * setvec)

float32 ratio = (frame - time1) / (time2 - time1);

float32 *frame1 = (float32 *) &Data[pidx+1];
float32 *frame2 = (float32 *) &Data[p2idx+1];
const uint32* frame1 = &Data[pidx+1];
const uint32* frame2 = &Data[p2idx+1];

for (int i=0; i < VectorLen; i++) {

setvec[i] = WWMath::Lerp(frame1[i],frame2[i],ratio);
setvec[i] = WWMath::Lerp(std::bit_cast<float32>(frame1[i]),std::bit_cast<float32>(frame2[i]),ratio);

}

}


// Sets a quaternion from the four floats stored in a packet.
static void Set_Quaternion_From_Packet(Quaternion& q, const uint32 packet[4])
{
q.Set(
std::bit_cast<float32>(packet[0]),
std::bit_cast<float32>(packet[1]),
std::bit_cast<float32>(packet[2]),
std::bit_cast<float32>(packet[3]));
}

Quaternion TimeCodedMotionChannelClass::Get_QuatVector(float32 frame)
{

Expand All @@ -488,9 +490,7 @@ Quaternion TimeCodedMotionChannelClass::Get_QuatVector(float32 frame)

if (pidx == ((NumTimeCodes - 1) * PacketSize)) {

float32 *vec = (float32 *) &Data[pidx+1];

q.Set(vec[0], vec[1], vec[2], vec[3]);
Set_Quaternion_From_Packet(q, &Data[pidx+1]);

return( q );

Expand All @@ -502,10 +502,7 @@ Quaternion TimeCodedMotionChannelClass::Get_QuatVector(float32 frame)
uint32 time = Data[p2idx];

if (time & W3D_TIMECODED_BINARY_MOVEMENT_FLAG) {
// its a binary movement!
float32 *vec = (float32 *) &Data[pidx+1];

q.Set(vec[0], vec[1], vec[2], vec[3]);
Set_Quaternion_From_Packet(q, &Data[pidx+1]);

return( q );
}
Expand All @@ -515,14 +512,11 @@ Quaternion TimeCodedMotionChannelClass::Get_QuatVector(float32 frame)

float32 ratio = (frame - time1) / (time2 - time1);

float32 *frame1 = (float32 *) &Data[pidx+1];
float32 *frame2 = (float32 *) &Data[p2idx+1];

Quaternion q1(1);
Quaternion q2(1);
Quaternion q1;
Quaternion q2;

q1.Set(frame1[0], frame1[1], frame1[2], frame1[3]);
q2.Set(frame2[0], frame2[1], frame2[2], frame2[3]);
Set_Quaternion_From_Packet(q1, &Data[pidx+1]);
Set_Quaternion_From_Packet(q2, &Data[p2idx+1]);

Fast_Slerp(q, q1, q2, ratio);

Expand Down Expand Up @@ -972,7 +966,7 @@ bool AdaptiveDeltaMotionChannelClass::Load_W3D(ChunkLoadClass & cload)
void AdaptiveDeltaMotionChannelClass::decompress(uint32 frame_idx, float *outdata)
{
// Start Over from the beginning
float *base = (float *) &Data[0]; // pointer to our true know beginning values
const uint32* base = &Data[0]; // pointer to our true know beginning values

bool done = false;

Expand All @@ -982,7 +976,7 @@ void AdaptiveDeltaMotionChannelClass::decompress(uint32 frame_idx, float *outdat
pPacket+= (sizeof(float) * VectorLen); // skip non-compressed header information
pPacket+= PACKET_SIZE * vi; // skip to the appropriate packet start

float last_value = base[vi];
float last_value = std::bit_cast<float>(base[vi]);

for (uint32 frame=1; frame<=frame_idx;) {
// Frame Loop
Expand Down Expand Up @@ -1048,8 +1042,7 @@ void AdaptiveDeltaMotionChannelClass::decompress(uint32 src_idx, float *srcdata,
assert(src_idx < frame_idx);
src_idx++;

float *base = (float *) &Data[0]; // pointer to our true know beginning values
base += VectorLen; // skip header information
const uint32* base = &Data[VectorLen]; // skip header information

bool done = false;

Expand Down
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