GLAPI/glGetShaderPrecisionFormat: Difference between revisions
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== Function Definition == | == Function Definition == | ||
void '''glGetShaderPrecisionFormat'''(GLenum | void '''glGetShaderPrecisionFormat'''(GLenum {{param|shaderType}}, GLenum {{param|precisionType}}, GLint *{{param|range}}, GLint *{{param|precision}}); | ||
; shaderType | ; shaderType | ||
: Specifies the type of shader whose precision to query. | : Specifies the type of shader whose precision to query. {{param|shaderType}} must be {{enum|GL_VERTEX_SHADER}} or {{enum|GL_FRAGMENT_SHADER}}. | ||
; precisionType | ; precisionType | ||
: Specifies the numeric format whose precision and range to query. | : Specifies the numeric format whose precision and range to query. | ||
| Line 22: | Line 22: | ||
== Description == | == Description == | ||
'''glGetShaderPrecisionFormat''' retrieves the numeric range and precision for the implementation's representation of quantities in different numeric formats in specified shader type. | '''glGetShaderPrecisionFormat''' retrieves the numeric range and precision for the implementation's representation of quantities in different numeric formats in specified shader type. {{param|shaderType}} specifies the type of shader for which the numeric precision and range is to be retrieved and must be one of {{enum|GL_VERTEX_SHADER}} or {{enum|GL_FRAGMENT_SHADER}}. {{param|precisionType}} specifies the numeric format to query and must be one of {{enum|GL_LOW_FLOAT}}, {{enum|GL_MEDIUM_FLOAT}}{{enum|GL_HIGH_FLOAT}}, {{enum|GL_LOW_INT}}, {{enum|GL_MEDIUM_INT}}, or {{enum|GL_HIGH_INT}}. | ||
{{param|range}} points to an array of two integers into which the format's numeric range will be returned. If min and max are the smallest values representable in the format, then the values returned are defined to be: {{param|range}}[0] = floor(log2(|min|)) and {{param|range}}[1] = floor(log2(|max|)). | |||
{{param|precision}} specifies the address of an integer into which will be written the log2 value of the number of bits of precision of the format. If the smallest representable value greater than 1 is 1 + ''eps'', then the integer addressed by {{param|precision}} will contain floor(-log2(eps)). | |||
== Errors == | == Errors == | ||
{{ | {{enum|GL_INVALID_ENUM}} is generated if {{param|shaderType}} or {{param|precisionType}} is not an accepted value. | ||
== Copyright == | == Copyright == | ||
| Line 36: | Line 36: | ||
Copyright © 2010 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. [http://opencontent.org/openpub/ http://opencontent.org/openpub/]. | Copyright © 2010 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. [http://opencontent.org/openpub/ http://opencontent.org/openpub/]. | ||
[[Category:API Reference | [[Category:Core API Ref Shader Program Query|GetShaderPrecisionFormat]] | ||
[[Category:Core API Reference|GetShaderPrecisionFormat]] | |||
[[Category:Program Object API State Functions|GetShaderPrecisionFormat]] | |||
Latest revision as of 10:01, 15 August 2013
| Core in version | 4.6 | |
|---|---|---|
| Core since version | 4.1 | |
| Core ARB extension | ARB_ES2_compatibility | |
glGetShaderPrecisionFormat: retrieve the range and precision for numeric formats supported by the shader compiler
Function Definition
void glGetShaderPrecisionFormat(GLenum shaderType, GLenum precisionType, GLint *range, GLint *precision);
- shaderType
- Specifies the type of shader whose precision to query. shaderType must be GL_VERTEX_SHADER or GL_FRAGMENT_SHADER.
- precisionType
- Specifies the numeric format whose precision and range to query.
- range
- Specifies the address of array of two integers into which encodings of the implementation's numeric range are returned.
- precision
- Specifies the address of an integer into which the numeric precision of the implementation is written.
Description
glGetShaderPrecisionFormat retrieves the numeric range and precision for the implementation's representation of quantities in different numeric formats in specified shader type. shaderType specifies the type of shader for which the numeric precision and range is to be retrieved and must be one of GL_VERTEX_SHADER or GL_FRAGMENT_SHADER. precisionType specifies the numeric format to query and must be one of GL_LOW_FLOAT, GL_MEDIUM_FLOATGL_HIGH_FLOAT, GL_LOW_INT, GL_MEDIUM_INT, or GL_HIGH_INT.
range points to an array of two integers into which the format's numeric range will be returned. If min and max are the smallest values representable in the format, then the values returned are defined to be: range[0] = floor(log2(|min|)) and range[1] = floor(log2(|max|)).
precision specifies the address of an integer into which will be written the log2 value of the number of bits of precision of the format. If the smallest representable value greater than 1 is 1 + eps, then the integer addressed by precision will contain floor(-log2(eps)).
Errors
GL_INVALID_ENUM is generated if shaderType or precisionType is not an accepted value.
Copyright
Copyright © 2010 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.