MW2 TU8 - BulletTrace fully reversed! - By XeSao

//Scr_BulletTrace fully reversed!
//Credits to Xx James t xX for the BulletTraceType as it is much easier with it
//Example on how to use it:

/*
BulletTraceType Type;
float start[3] = { 123, 435, 642 },
    end[3] = { 130, 450, 642 };
int Client = 3;
bulletTrace(&Type, start, end, Client, true);

if(!strcmp(Type.surfaceType, "default"))
    setOrigin(Type.entity, Type.position);
*/


typedef struct BulletTraceType
{
    short entityid;
    float position[3];
    TraceHitType hitType;
    char *surfaceFlag;
    int entity;
};

typedef enum TraceHitType
{
    TRACE_HITTYPE_NONE,
    TRACE_HITTYPE_ENTITY,
    TRACE_HITTYPE_DYNENT_MODEL,
    TRACE_HITTYPE_DYNENT_BRUSH,
    TRACE_HITTYPE_UNKNOWN
};

typedef struct trace_t
{
    float fraction;//0x00 - 0x04
    float normal[3];//0x04 - 0x10
    int surfaceFlags;//0x10 - 0x14
    int contents;//0x14 - 0x18
    const char *material;//0x18 - 0x1C
    TraceHitType hitType;//0x1C - 0x20
    unsigned __int16 hitId; //0x20 - 0x22
    unsigned __int16 modelIndex;//0x22 - 0x24
    unsigned __int16 partName;//0x24 - 0x26
    unsigned __int16 partGroup;//0x26 - 0x38
    bool allsolid;//0x28 - 0x29
    bool startsolid;//0x29 - 0x2A
    bool walkable;//0x2A-0x2B
};

void bulletTrace(BulletTraceType *Type, float *start, float *end, int hitEntity, int ignoreEnt)
{
    trace_t result;
    G_LocationalTrace(&result, start, end, !hitEntity ? 0x7FF : hitEntity, !ignoreEnt ? 0x806831 : 0x2806831, 0);
    for(int i = 0;i < 3;i ++)
        Type->position[i] = (((end[i] - start[i]) * result.fraction) + start[i]);
    unsigned short hitid = Trace_GetEntityHitId(&result) & 0xFFFF;
    if(hitid & 0x7FE || hitid & 0x7FF)
        Type->entityid = hitid;
    else
        Type->entityid = gEntity(hitid);
    if(result.fraction >= 1)
    {
        int r10, r11 = result.surfaceFlags;
        __asm srawi     r10, r11, 0x14
        Type->surfaceFlag = Com_SurfaceTypeToName(r10 &= 0xF8000000);
    }
    float f12;
    if(-sqrt((((end[0] - start[0]) * (end[0] - start[0])) + (((end[2] - start[2]) * (end[2] - start[2])) + ((end[1] - start[1]) * (end[1] - start[1]))))) >= 0 ||
    -sqrt((((end[0] - start[0]) * (end[0] - start[0])) + (((end[2] - start[2]) * (end[2] - start[2])) + ((end[1] - start[1]) * (end[1] - start[1]))))) == 0)
        f12 = 1;
    else if(-sqrt((((end[0] - start[0]) * (end[0] - start[0])) + (((end[2] - start[2]) * (end[2] - start[2])) + ((end[1] - start[1]) * (end[1] - start[1]))))) <= 0)
        f12 = sqrt((((end[0] - start[0]) * (end[0] - start[0])) + (((end[2] - start[2]) * (end[2] - start[2])) + ((end[1] - start[1]) * (end[1] - start[1])))));
    float f9 = ((1 / f12) * (end[0] - start[0]));
    float f7 = ((end[1] - start[1]) * (1 / f12));
    float f6 = ((end[2] - start[2]) * (1 / f12));
    float Normal[3] = { f9, f7, f6 };
    for(int i = 0;i < 3;i++)
        result.normal[i] = Normal[i];
    Type->hitType = result.hitType;
    Type->entity = gEntity(hitid);
}