glGetMinmax
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## Name

glGetMinmax — get minimum and maximum pixel values

## C Specification

`void `glGetMinmax`` | `(` | `GLenum `target`, GLboolean `reset`, GLenum `format`, GLenum `type`, GLvoid *`values`);`

## Python Specification

``glGetMinmax`` | `(` | ``target`, `reset`, `format`, `type`, `values`) → `None``

## Parameters

`target`
  Must be `GL_MINMAX`.
`reset`
  If `GL_TRUE`, all entries in the minmax table that are actually returned are reset to their initial values. (Other entries are unaltered.) If `GL_FALSE`, the minmax table is unaltered.
`format`
  The of the data to be returned in `values`. Must be one of `GL_RED`, `GL_GREEN`, `GL_BLUE`, `GL_ALPHA`, `GL_RGB`, `GL_BGR`, `GL_RGBA`, `GL_BGRA`, `GL_LUMINANCE`, or `GL_LUMINANCE_ALPHA`.
`type`
  The type of the data to be returned in `values`. Symbolic constants `GL_UNSIGNED_BYTE`, `GL_BYTE`, `GL_BITMAP`, `GL_UNSIGNED_SHORT`, `GL_SHORT`, `GL_UNSIGNED_INT`, `GL_INT`, `GL_FLOAT`, `GL_UNSIGNED_BYTE_3_3_2`, `GL_UNSIGNED_BYTE_2_3_3_REV`, `GL_UNSIGNED_SHORT_5_6_5`, `GL_UNSIGNED_SHORT_5_6_5_REV`, `GL_UNSIGNED_SHORT_4_4_4_4`, `GL_UNSIGNED_SHORT_4_4_4_4_REV`, `GL_UNSIGNED_SHORT_5_5_5_1`, `GL_UNSIGNED_SHORT_1_5_5_5_REV`, `GL_UNSIGNED_INT_8_8_8_8`, `GL_UNSIGNED_INT_8_8_8_8_REV`, `GL_UNSIGNED_INT_10_10_10_2`, and `GL_UNSIGNED_INT_2_10_10_10_REV` are accepted.
`values`
  A pointer to storage for the returned values.

## Description

`glGetMinmax` returns the accumulated minimum and maximum pixel values (computed on a per-component basis) in a one-dimensional image of width 2. The first set of return values are the minima, and the second set of return values are the maxima. The of the return values is determined by `format`, and their type is determined by `type`.

No pixel transfer operations are performed on the return values, but pixel storage modes that are applicable to 1-dimensional images are performed. Color components that are requested in the specified `format`, but that are not included in the internal of the minmax table, are returned as zero. The assignment of internal color components to the components requested by `format` are as follows:

Internal Component | Resulting Component
Red | Red
Green | Green
Blue | Blue
Alpha | Alpha
Luminance | Red

If `reset` is `GL_TRUE`, the minmax table entries corresponding to the return values are reset to their initial values. Minimum and maximum values that are not returned are not modified, even if `reset` is `GL_TRUE`.

## Notes

`glGetMinmax` is present only if `GL_ARB_imaging` is returned when `glGetString` is called with an argument of `GL_EXTENSIONS`.

## Errors

`GL_INVALID_ENUM` is generated if `target` is not `GL_MINMAX`.

`GL_INVALID_ENUM` is generated if `format` is not one of the allowable values.

`GL_INVALID_ENUM` is generated if `type` is not one of the allowable values.

`GL_INVALID_OPERATION` is generated if `glGetMinmax` is executed between the execution of `glBegin` and the corresponding execution of `glEnd`.

`GL_INVALID_OPERATION` is generated if `type` is one of `GL_UNSIGNED_BYTE_3_3_2`, `GL_UNSIGNED_BYTE_2_3_3_REV`, `GL_UNSIGNED_SHORT_5_6_5`, or `GL_UNSIGNED_SHORT_5_6_5_REV` and `format` is not `GL_RGB`.

`GL_INVALID_OPERATION` is generated if `type` is one of `GL_UNSIGNED_SHORT_4_4_4_4`, `GL_UNSIGNED_SHORT_4_4_4_4_REV`, `GL_UNSIGNED_SHORT_5_5_5_1`, `GL_UNSIGNED_SHORT_1_5_5_5_REV`, `GL_UNSIGNED_INT_8_8_8_8`, `GL_UNSIGNED_INT_8_8_8_8_REV`, `GL_UNSIGNED_INT_10_10_10_2`, or `GL_UNSIGNED_INT_2_10_10_10_REV` and `format` is neither `GL_RGBA` nor `GL_BGRA`.

## See Also

glMinmax, glResetMinmax, glGetMinmaxParameter

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