[HL] MP5/M4 bullet hole decals

[Matthaiks]

Two shots, but only one bullet hole is visible. Other guns are fine.

http://youtu.be/AiL51bQnCMY

Exe version 1.1.2.2/Stdio (valve)
Exe build: 12:05:47 Feb 18 2013 (5961)

Processor Information:
Vendor: AuthenticAMD
Speed: 3214 Mhz
4 logical processors
4 physical processors
HyperThreading: Unsupported
FCMOV: Supported
SSE2: Supported
SSE3: Supported
SSSE3: Supported
SSE4a: Supported
SSE41: Unsupported
SSE42: Unsupported

Network Information:
Network Speed:

Operating System Version:
Windows 7 (64 bit)
NTFS: Supported
Crypto Provider Codes: Supported 311 0x0 0x0 0x0

Video Card:
Driver: ATI Radeon HD 5700 Series

DirectX Driver Name:  aticfx32.dll
Driver Version:  9.12.0.0
DirectX Driver Version:  8.17.10.1172
Driver Date: 19 Dec 2012
Desktop Color Depth: 32 bits per pixel
Monitor Refresh Rate: 60 Hz
DirectX Card: ATI Radeon HD 5700 Series
VendorID:  0x1002
DeviceID:  0x68b8
Number of Monitors:  1
Number of Logical Video Cards:  1
No SLI or Crossfire Detected
Primary Display Resolution:  1920 x 1200
Desktop Resolution: 1920 x 1200
Primary Display Size: 26.65" x 16.65"  (31.42" diag)
                                        67.7cm x 42.3cm  (79.8cm diag)
Primary Bus Type Not Detected
Primary VRAM: 1024 MB
Supported MSAA Modes:  2x 4x 8x 

[ghost]

This bug is very old. I can reproduce it in WON version (Build 893. Exe: 12:20:12 Apr 5 1999)

[SamVanheer]

This happens because the game deliberately doesn't create decals if the tracer count for bullets being fired is > 0.

This comment implies it's intentional:

halflife/dlls/combat.cpp

Line 1418 in c7240b9

if ( iTracerFreq != 1 ) // guns that always trace also always decal

But this is clearly not the expected behavior.

It only happens when firing 12MM bullets (func_tank does this):

halflife/dlls/combat.cpp

Lines 1469 to 1476 in c7240b9

	case BULLET_MONSTER_12MM:
	pEntity->TraceAttack(pevAttacker, gSkillData.monDmg12MM, vecDir, &tr, DMG_BULLET);
	if ( !tracer )
	{
	TEXTURETYPE_PlaySound(&tr, vecSrc, vecEnd, iBulletType);
	DecalGunshot( &tr, iBulletType );
	}
	break;

And when firing MP5 bullets:

halflife/cl_dll/ev_hldm.cpp

Lines 419 to 426 in c7240b9

	case BULLET_PLAYER_MP5:
	if ( !tracer )
	{
	EV_HLDM_PlayTextureSound( idx, &tr, vecSrc, vecEnd, iBulletType );
	EV_HLDM_DecalGunshot( &tr, iBulletType );
	}
	break;

Opposing Force has similar checks for NPC fired 556 and 762 bullets.

The fix is to remove the tracer variable check. Then decals are always applied. You don't need the tracer variable at all so it can be removed.