OpenGL2: Dlight behavior close to surface

[WHS-Phoenix]

With cl_renderer OpenGL2 and r_dlightmode 1 or higher, dynamic lights close to or at a surface cause the light to draw extremely dim, while lighting adjacent surfaces. Examples:

Dlight in flight open air:

Dlight impacting wall (floor lights, wall lights badly):

Dlight impacting floor (wall lights, floor lights badly):

Comparison to Quake 2 (Kex Engine):

Dlight in flight open air:

Dlight impacting wall:

Dlight impacting floor:

[WHS-Phoenix]

Update on this behavior:

In the Quake3e engine, this is a result of a specularity program being run on the dynamic lights.

r_dlightSpecPower "8" yields this when shooting the wall (the light intensity is diminished on the wall surface when the source is near the wall plane).

r_dlightSpecPower "1" yields the desired result:

In the Quake3e engine this is controlled by ARB_BuildDlightFP in tr_arb.c, specifically this line:

if ( r_dlightSpecColor->value > 0 )
    strcat( program, va( "PARAM specRGB = %1.2f; \n", r_dlightSpecColor->value ) );

I cannot find an analogue within the IOQuake3 source but the behavior looks to be similar.