/// <summary>
/// R_BuildLightMap
/// Combine and scale multiple lightmaps into the 8.8 format in blocklights
/// </summary>
static void BuildLightMap(msurface_t surf, ByteArraySegment dest, int stride)
{
surf.cached_dlight = (surf.dlightframe == _FrameCount);
int smax = (surf.extents[0] >> 4) + 1;
int tmax = (surf.extents[1] >> 4) + 1;
int size = smax * tmax;
int srcOffset = surf.sampleofs;
byte[] lightmap = surf.sample_base;// surf.samples;
// set to full bright if no light data
if (_FullBright.Value != 0 || Client.cl.worldmodel.lightdata == null)
{
for (int i = 0; i < size; i++)
{
_BlockLights[i] = 255 * 256;
}
}
else
{
// clear to no light
for (int i = 0; i < size; i++)
{
_BlockLights[i] = 0;
}
// add all the lightmaps
if (lightmap != null)
{
for (int maps = 0; maps < BspFile.MAXLIGHTMAPS && surf.styles[maps] != 255; maps++)
{
int scale = _LightStyleValue[surf.styles[maps]];
surf.cached_light[maps] = scale; // 8.8 fraction
for (int i = 0; i < size; i++)
{
_BlockLights[i] += (uint)(lightmap[srcOffset + i] * scale);
}
srcOffset += size; // lightmap += size; // skip to next lightmap
}
}
// add all the dynamic lights
if (surf.dlightframe == _FrameCount)
{
AddDynamicLights(surf);
}
}
// bound, invert, and shift
//store:
int blOffset = 0;
int destOffset = dest.StartIndex;
byte[] data = dest.Data;
switch (Drawer.LightMapFormat)
{
case PixelFormat.Rgba:
stride -= (smax << 2);
for (int i = 0; i < tmax; i++, destOffset += stride) // dest += stride
{
for (int j = 0; j < smax; j++)
{
uint t = _BlockLights[blOffset++]; // *bl++;
t >>= 7;
if (t > 255)
{
t = 255;
}
data[destOffset + 3] = (byte)(255 - t); //dest[3] = 255 - t;
destOffset += 4;
}
}
break;
case PixelFormat.Alpha:
case PixelFormat.Luminance:
//case GL_INTENSITY:
for (int i = 0; i < tmax; i++, destOffset += stride)
{
for (int j = 0; j < smax; j++)
{
uint t = _BlockLights[blOffset++]; // *bl++;
t >>= 7;
if (t > 255)
{
t = 255;
}
data[destOffset + j] = (byte)(255 - t); // dest[j] = 255 - t;
}
}
break;
default:
Sys.Error("Bad lightmap format");
break;
}
}