Lights Don't Work (#124)

[OrbWeaver]

I have investigated this issue and it seems that it is a problem with lights that do not specify a lightfalloffimage. Previously in this case the renderer would detect that the bound verticle texture was numbered 0 and would therefore know to use the default, however this no longer seems to be happening -- instead the texture is bound to a new number which presumably corresponds to a black or invalid texture rather than the default point light falloff.

 

I have also confirmed this by copying the biground1 light texture and adding the same lightfalloffimage as with defaultpointlight, whereafter it works.

 

Greebo -- there is a note in the flushRenderables method:

 

// greebo: Note, that the check for empty texture_numbers should not
// necessarily be placed here, that kind of error handling should go into
// the shaders module.

 

How should we check for a light shader which has no falloff now? I am quite happy to move it out of the renderer (and get rid of the horrible g_defaultPointLight global). Perhaps it should go in the shaders plugin, for instance, whereby a light texture with no falloff gets a default instead of a blank name/empty pointer.

[greebo]

You should be able to specify a default fall off image in the GLTextureManager. When a Shader is requested to deliver its TexturePtr lightFallOffImage() it checks its template for a definition. If that one is not found, it requests the emptyFallOffImage() from the GLTextureManager.

 

Compare CShader::lightFalloffImage():

if (_texLightFalloff == NULL) {
	// TODO: Move this algorithm into a FallOffConstructor object
	// deriving from a TextureConstructor class, if appropriate (check). 

	if (_template._lightFallOff) {
		// There is a lightfalloff defined in the template
		std::string foTexName = _template._lightFallOff->getTextureName();

		// Pass the call to the GLTextureManager to realise this image 
		_texLightFalloff = GetTextureManager().getBinding(
			foTexName,
			_falloffConstructor,
			texLightFalloff
		);
	}
	else {
		// No falloff defined in the template
		_texLightFalloff = GetTextureManager().getEmptyFalloff();
	}
}
return _texLightFalloff;

The emptyLightFallOff() method is probably a misnomer and should be renamed to defaultLightFallOff().

 

There is a constant in the GLTextureManager which specifies the actual bmp image to be used.

[OrbWeaver]

I see, this will be the problem:

 

const std::string SHADER_FALLOFF_EMPTY = "bitmaps/_black.bmp";

 

The last thing we want is to default to a black falloff image, this will turn off the light. I will look into adjusting the shaders plugin so that empty falloff textures are instead retrieved from the defaultPointLight shader, since this is the behaviour that Doom 3 exhibits and we want to match it as closely as possible.