GLAPI/glDrawArrays: Difference between revisions

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== Function Definition ==
== Function Definition ==


   void '''glDrawArrays'''(GLenum ''mode'', GLint ''first'', GLsizei ''count'');
   void '''glDrawArrays'''(GLenum {{param|mode}}, GLint {{param|first}}, GLsizei {{param|count}});


; mode
; mode
: Specifies what kind of primitives to render. Symbolic constants {{code|GL_POINTS}}, {{code|GL_LINE_STRIP}}, {{code|GL_LINE_LOOP}}, {{code|GL_LINES}}, {{code|GL_LINE_STRIP_ADJACENCY}}, {{code|GL_LINES_ADJACENCY}}, {{code|GL_TRIANGLE_STRIP}}, {{code|GL_TRIANGLE_FAN}}, {{code|GL_TRIANGLES}}, {{code|GL_TRIANGLE_STRIP_ADJACENCY}}, {{code|GL_TRIANGLES_ADJACENCY}} and {{code|GL_PATCHES}} are accepted.
: Specifies what kind of primitives to render. Symbolic constants {{enum|GL_POINTS}}, {{enum|GL_LINE_STRIP}}, {{enum|GL_LINE_LOOP}}, {{enum|GL_LINES}}, {{enum|GL_LINE_STRIP_ADJACENCY}}, {{enum|GL_LINES_ADJACENCY}}, {{enum|GL_TRIANGLE_STRIP}}, {{enum|GL_TRIANGLE_FAN}}, {{enum|GL_TRIANGLES}}, {{enum|GL_TRIANGLE_STRIP_ADJACENCY}}, {{enum|GL_TRIANGLES_ADJACENCY}} and {{enum|GL_PATCHES}} are accepted.
; first
; first
: Specifies the starting index in the enabled arrays.
: Specifies the starting index in the enabled arrays.
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'''glDrawArrays''' specifies multiple geometric primitives with very few subroutine calls. Instead of calling a GL procedure to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify separate arrays of vertices, normals, and colors and use them to construct a sequence of primitives with a single call to '''glDrawArrays'''.
'''glDrawArrays''' specifies multiple geometric primitives with very few subroutine calls. Instead of calling a GL procedure to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify separate arrays of vertices, normals, and colors and use them to construct a sequence of primitives with a single call to '''glDrawArrays'''.


When '''glDrawArrays''' is called, it uses ''count'' sequential elements from each enabled array to construct a sequence of geometric primitives, beginning with element ''first''. ''mode'' specifies what kind of primitives are constructed and how the array elements construct those primitives.
When '''glDrawArrays''' is called, it uses {{param|count}} sequential elements from each enabled array to construct a sequence of geometric primitives, beginning with element {{param|first}}. {{param|mode}} specifies what kind of primitives are constructed and how the array elements construct those primitives.


Vertex attributes that are modified by '''glDrawArrays''' have an unspecified value after '''glDrawArrays''' returns. Attributes that aren't modified remain well defined.
Vertex attributes that are modified by '''glDrawArrays''' have an unspecified value after '''glDrawArrays''' returns. Attributes that aren't modified remain well defined.
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== Notes ==
== Notes ==


{{code|GL_LINE_STRIP_ADJACENCY}}, {{code|GL_LINES_ADJACENCY}}, {{code|GL_TRIANGLE_STRIP_ADJACENCY}} and {{code|GL_TRIANGLES_ADJACENCY}} are available only if the GL version is 3.2 or greater.
{{enum|GL_LINE_STRIP_ADJACENCY}}, {{enum|GL_LINES_ADJACENCY}}, {{enum|GL_TRIANGLE_STRIP_ADJACENCY}} and {{enum|GL_TRIANGLES_ADJACENCY}} are available only if the GL version is 3.2 or greater.


== Errors ==
== Errors ==


{{code|GL_INVALID_ENUM}} is generated if ''mode'' is not an accepted value.
{{enum|GL_INVALID_ENUM}} is generated if {{param|mode}} is not an accepted value.


{{code|GL_INVALID_VALUE}} is generated if ''count'' is negative.
{{enum|GL_INVALID_VALUE}} is generated if {{param|count}} is negative.


{{code|GL_INVALID_OPERATION}} is generated if a non-zero buffer object name is bound to an enabled array and the buffer object's data store is currently mapped.
{{enum|GL_INVALID_OPERATION}} is generated if a non-zero buffer object name is bound to an enabled array and the buffer object's data store is currently mapped.


{{code|GL_INVALID_OPERATION}} is generated if a geometry shader is active and ''mode'' is incompatible with the input primitive type of the geometry shader in the currently installed program object.
{{enum|GL_INVALID_OPERATION}} is generated if a geometry shader is active and {{param|mode}} is incompatible with the input primitive type of the geometry shader in the currently installed program object.


== See Also ==
== See Also ==


[[GLAPI/glDrawArraysInstanced|glDrawArraysInstanced]], [[GLAPI/glDrawElements|glDrawElements]], [[GLAPI/glDrawRangeElements|glDrawRangeElements]],
{{apifunc|glBindVertexArray}}, {{apifunc|glDrawArraysIndirect}}, {{apifunc|glDrawArraysInstanced}}, {{apifunc|glDrawArraysInstancedBaseInstance}}, {{apifunc|glMultiDrawArrays}}, {{apifunc|glMultiDrawArraysIndirect}}


== Copyright ==
== Copyright ==


Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see [http://oss.sgi.com/projects/FreeB/ http://oss.sgi.com/projects/FreeB/].
Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see [https://khronos.org/registry/OpenGL-Refpages/LICENSES/LicenseRef-FreeB.txt LicenseRef-FreeB].


[[Category:API Reference 4|DrawArrays]]
[[Category:Core API Ref Vertex Rendering|DrawArrays]]
[[Category:GL 4 API Vertex Rendering|DrawArrays]]
[[Category:Core API Reference|DrawArrays]]

Latest revision as of 21:49, 5 February 2021

glDrawArrays
Core in version 4.6
Core since version 1.1

glDrawArrays: render primitives from array data

Function Definition

 void glDrawArrays(GLenum mode​, GLint first​, GLsizei count​);
mode
Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_LINE_STRIP_ADJACENCY, GL_LINES_ADJACENCY, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES, GL_TRIANGLE_STRIP_ADJACENCY, GL_TRIANGLES_ADJACENCY and GL_PATCHES are accepted.
first
Specifies the starting index in the enabled arrays.
count
Specifies the number of indices to be rendered.

Description

glDrawArrays specifies multiple geometric primitives with very few subroutine calls. Instead of calling a GL procedure to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify separate arrays of vertices, normals, and colors and use them to construct a sequence of primitives with a single call to glDrawArrays.

When glDrawArrays is called, it uses count​ sequential elements from each enabled array to construct a sequence of geometric primitives, beginning with element first​. mode​ specifies what kind of primitives are constructed and how the array elements construct those primitives.

Vertex attributes that are modified by glDrawArrays have an unspecified value after glDrawArrays returns. Attributes that aren't modified remain well defined.

Notes

GL_LINE_STRIP_ADJACENCY, GL_LINES_ADJACENCY, GL_TRIANGLE_STRIP_ADJACENCY and GL_TRIANGLES_ADJACENCY are available only if the GL version is 3.2 or greater.

Errors

GL_INVALID_ENUM is generated if mode​ is not an accepted value.

GL_INVALID_VALUE is generated if count​ is negative.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array and the buffer object's data store is currently mapped.

GL_INVALID_OPERATION is generated if a geometry shader is active and mode​ is incompatible with the input primitive type of the geometry shader in the currently installed program object.

See Also

glBindVertexArray, glDrawArraysIndirect, glDrawArraysInstanced, glDrawArraysInstancedBaseInstance, glMultiDrawArrays, glMultiDrawArraysIndirect

Copyright

Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see LicenseRef-FreeB.

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