lovr.graphics.newShader

Creates a new Shader.

Create a Shader with custom GLSL code.

shader = lovr.graphics.newShader(vertex, fragment, options)

Arguments

Name	Type	Default	Description
vertex	string		The code or filename of the vertex shader. If nil, the default vertex shader is used.
fragment	string		The code or filename of the fragment shader. If nil, the default fragment shader is used.
options	table	{}	Optional settings for the Shader.
.flags	table	{}	A table of key-value options passed to the Shader.
.stereo	boolean	true	Whether the Shader should be configured for stereo rendering (Currently Android-only).

Returns

Name	Type	Description
shader	Shader	The new Shader.

---

Create a new instance of a built-in Shader.

shader = lovr.graphics.newShader(default, options)

Arguments

Name	Type	Default	Description
default	DefaultShader		A builtin shader to use for the shader code.
options	table	{}	Optional settings for the Shader.
.flags	table	{}	A table of key-value options passed to the Shader.
.stereo	boolean	true	Whether the Shader should be configured for stereo rendering (Currently Android-only).

Returns

Name	Type	Description
shader	Shader	The new Shader.

Notes

The flags table should contain string keys, with boolean or numeric values. These flags can be used to customize the behavior of Shaders from Lua, by using the flags in the shader source code. Numeric flags will be available as constants named FLAG_<flagName>. Boolean flags can be used with #ifdef and will only be defined if the value in the Lua table was true.

The following flags are used by shaders provided by LÖVR:

• animated is a boolean flag that will cause the shader to position vertices based on the pose of an animated skeleton. This should usually only be used for animated Models, since it needs a skeleton to work properly and is slower than normal rendering.
• alphaCutoff is a numeric flag that can be used to implement simple "cutout" style transparency, where pixels with alpha below a certain threshold will be discarded. The value of the flag should be a number between 0.0 and 1.0, representing the alpha treshold.
• uniformScale is a boolean flag used for optimization. If the Shader is only going to be used with objects that have a uniform scale (i.e. the x, y, and z components of the scale are all the same number), then this flag can be set to use a faster method to compute the lovrNormalMatrix uniform variable.
• multicanvas is a boolean flag that should be set when rendering to multiple Textures attached to a Canvas. When set, the fragment shader should implement the colors function instead of the color function, and can write color values to the lovrCanvas array instead of returning a single color. Each color in the array gets written to the corresponding texture attached to the canvas.
• highp is a boolean flag specific to mobile GPUs that changes the default precision for fragment shaders to use high precision instead of the default medium precision. This can fix visual issues caused by a lack of precision, but isn't guaranteed to be supported on some lower-end systems.
• The following flags are used only by the standard PBR shader:
  • normalMap should be set to true to render objects with a normal map, providing a more detailed, bumpy appearance. Currently, this requires the model to have vertex tangents.
  • emissive should be set to true to apply emissive maps to rendered objects. This is usually used to apply glowing lights or screens to objects, since the emissive texture is not affected at all by lighting.
  • indirectLighting is an awesome boolean flag that will apply realistic reflections and lighting to the surface of an object, based on a specially-created skybox. See the Standard Shader guide for more information.
  • occlusion is a boolean flag that uses the ambient occlusion texture in the model. It only affects indirect lighting, so it will only have an effect if the indirectLighting flag is also enabled.
  • skipTonemap is a flag that will skip the tonemapping process. Tonemapping is an important process that maps the high definition physical color values down to a 0 - 1 range for display. There are lots of different tonemapping algorithms that give different artistic effects. The default tonemapping in the standard shader is the ACES algorithm, but you can use this flag to turn off ACES and use your own tonemapping.

Currently, up to 32 shader flags are supported.

The stereo option is only necessary for Android. Currently on Android, only stereo shaders can be used with stereo Canvases, and mono Shaders can only be used with mono Canvases.

See also

• lovr.graphics.setShader
• lovr.graphics.getShader
• lovr.graphics.newComputeShader
• lovr.graphics