Difference between revisions of "Shader Variables"

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== Global built-in variables ==
 
== Global built-in variables ==
{{param|mat4|TransformMatrix|The transformation matrix affected by [[love.graphics.translate]] and friends.}}
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{{param|mat4|TransformMatrix|The transformation matrix affected by [[love.graphics.translate]] and friends. Note that automatically batched vertices are transformed on the CPU, and their TransformMatrix will be an identity matrix.}}
  
 
{{param|mat4|ProjectionMatrix|The orthographic projection matrix.}}
 
{{param|mat4|ProjectionMatrix|The orthographic projection matrix.}}
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== Pixel Shader built-in variables ==
 
== Pixel Shader built-in variables ==
 
{{param|vec4 array|love_Canvases[]|Array used to set per-canvas pixel colors when multiple canvases are set with [[love.graphics.setCanvas]] and the [[love.graphics.newShader#Pixel Shader Function|effects]] function is used instead of <code>effect</code>. Note that arrays in shaders are 0-based. Writable in the pixel shader when the '''effects''' function is used.}}
 
{{param|vec4 array|love_Canvases[]|Array used to set per-canvas pixel colors when multiple canvases are set with [[love.graphics.setCanvas]] and the [[love.graphics.newShader#Pixel Shader Function|effects]] function is used instead of <code>effect</code>. Note that arrays in shaders are 0-based. Writable in the pixel shader when the '''effects''' function is used.}}
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{{param|vec2|love_PixelCoord|Coordinates of the pixel on screen. The same as <code>screen_coords</code> passed to the <code>vec4 effect</code> [[love.graphics.newShader#Pixel_Shader_Function|Shader function]]}}
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=== Notes ===
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If you wish to access the texture used for the drawing operation, you may define a uniform called <code>MainTex</code> of the appropriate type yourself, e.g. <code>uniform Image MainTex;</code>
  
 
== See Also ==
 
== See Also ==

Latest revision as of 01:46, 16 February 2019

Available since LÖVE 0.9.0
These built-in shader variables are not supported in earlier versions.

There are several built-in variables LÖVE provides in vertex and pixel shaders. All built-in variables are read-only unless otherwise specified.

Global built-in variables

mat4 TransformMatrix
The transformation matrix affected by love.graphics.translate and friends. Note that automatically batched vertices are transformed on the CPU, and their TransformMatrix will be an identity matrix.
mat4 ProjectionMatrix
The orthographic projection matrix.
mat4 TransformProjectionMatrix
The combined transform and projection matrices. Used as the transform_projection argument to the vertex shader position function.
vec4 VaryingTexCoord
The interpolated per-vertex texture coordinate. Automatically set to the value of VertexTexCoord in the vertex shader before the position function is called. Used as the texture_coords argument to the pixel shader effect function. Writable in the vertex shader. Use this variable to change the texture coordinate in the vertex shader.
vec4 VaryingColor
The interpolated per-vertex color. Automatically set to the value of ConstantColor * gammaCorrectColor(VertexColor) in LÖVE 0.10.0 and newer, or VertexColor in 0.9.2 and older, in the vertex shader before the position function is called. Used as the color argument to the pixel shader effect function. Writable in the vertex shader. Use this variable to change the per-vertex or constant color in the vertex shader.
Available since LÖVE 0.9.1
This shader variable is not supported in earlier versions.
vec4 love_ScreenSize
The width and height of the screen (or canvas) currently being rendered to, stored in the x and y components of the variable. The z and w components are used internally by LÖVE. You can convert it to a vec2 with love_ScreenSize.xy or vec2(love_ScreenSize).

Vertex Shader built-in variables

vec4 VertexPosition
The pre-transformed position of the vertex. Used as the vertex_position argument to the vertex shader position function. The third and fourth components of the vector are normally (0, 1).
vec4 VertexTexCoord
The texture coordinate of the vertex. The third and fourth components of the vector are normally (0, 1). Meshes allow for custom texture coordinates.
vec4 VertexColor
The color of the vertex, sprite, or text character if a Mesh, SpriteBatch, or Text object with per-vertex colors is drawn, or in LÖVE 0.9.2 and older the global color set with love.graphics.setColor. It does not have gamma-correction applied.
Available since LÖVE 0.10.0
This shader variable is not supported in earlier versions.
vec4 ConstantColor
The global color set with love.graphics.setColor. If global gamma-correction is enabled, it will already be gamma-corrected.

Pixel Shader built-in variables

vec4 array love_Canvases[]
Array used to set per-canvas pixel colors when multiple canvases are set with love.graphics.setCanvas and the effects function is used instead of effect. Note that arrays in shaders are 0-based. Writable in the pixel shader when the effects function is used.
vec2 love_PixelCoord
Coordinates of the pixel on screen. The same as screen_coords passed to the vec4 effect Shader function

Notes

If you wish to access the texture used for the drawing operation, you may define a uniform called MainTex of the appropriate type yourself, e.g. uniform Image MainTex;

See Also

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