Difference between revisions of "GLAPI/glDrawArraysInstanced"

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m (Renaming category: 'GL 4 API Vertex Rendering' to 'Core API Ref Vertex Rendering'.)
(Function Definition)
 
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== Function Definition ==
 
== Function Definition ==
  
   void '''glDrawArraysInstanced'''(GLenum ''mode'', GLint ''first'', GLsizei ''count'', GLsizei ''primcount'');
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   void '''glDrawArraysInstanced'''(GLenum {{param|mode}}, GLint {{param|first}}, GLsizei {{param|count}}, GLsizei {{param|primcount}});
  
 
; 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_TRIANGLE_STRIP}}, {{code|GL_TRIANGLE_FAN}}, {{code|GL_TRIANGLES}}{{code|GL_LINES_ADJACENCY}}, {{code|GL_LINE_STRIP_ADJACENCY}}, {{code|GL_TRIANGLES_ADJACENCY}}, {{code|GL_TRIANGLE_STRIP_ADJACENCY}} and {{code|GL_PATCHES}} are accepted.
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: 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_TRIANGLE_STRIP}}, {{enum|GL_TRIANGLE_FAN}}, {{enum|GL_TRIANGLES}}, {{enum|GL_LINES_ADJACENCY}}, {{enum|GL_LINE_STRIP_ADJACENCY}}, {{enum|GL_TRIANGLES_ADJACENCY}}, {{enum|GL_TRIANGLE_STRIP_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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== Description ==
 
== Description ==
  
'''glDrawArraysInstanced''' behaves identically to [[GLAPI/glDrawArrays|glDrawArrays]] except that ''primcount'' instances of the range of elements are executed and the value of the internal counter ''instanceID'' advances for each iteration. ''instanceID'' is an internal 32-bit integer counter that may be read by a vertex shader as {{code|gl_InstanceID}}.
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'''glDrawArraysInstanced''' behaves identically to {{apifunc|glDrawArrays}} except that {{param|primcount}} instances of the range of elements are executed and the value of the internal counter {{param|instanceID}} advances for each iteration. {{param|instanceID}} is an internal 32-bit integer counter that may be read by a vertex shader as {{enum|gl_InstanceID}}.
  
 
'''glDrawArraysInstanced''' has the same effect as:  
 
'''glDrawArraysInstanced''' has the same effect as:  
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== Errors ==
 
== Errors ==
  
{{code|GL_INVALID_ENUM}} is generated if ''mode'' is not one of the accepted values.
+
{{enum|GL_INVALID_ENUM}} is generated if {{param|mode}} is not one of the accepted values.
  
{{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.
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{{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.
  
{{code|GL_INVALID_VALUE}} is generated if ''count'' or ''primcount'' are negative.
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{{enum|GL_INVALID_VALUE}} is generated if {{param|count}} or {{param|primcount}} are 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.
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{{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.
  
 
== See Also ==
 
== See Also ==
  
[[GLAPI/glDrawArrays|glDrawArrays]], [[GLAPI/glDrawElementsInstanced|glDrawElementsInstanced]]
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{{apifunc|glBindVertexArray}}, {{apifunc|glDrawArrays}}, {{apifunc|glDrawArraysIndirect}}, {{apifunc|glDrawArraysInstancedBaseInstance}}, {{apifunc|glMultiDrawArrays}}, {{apifunc|glMultiDrawArraysIndirect}}
  
 
== Copyright ==
 
== Copyright ==
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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 4|DrawArraysInstanced]]
 
 
[[Category:Core API Ref Vertex Rendering|DrawArraysInstanced]]
 
[[Category:Core API Ref Vertex Rendering|DrawArraysInstanced]]
 +
[[Category:Core API Reference|DrawArraysInstanced]]

Latest revision as of 21:31, 10 January 2013

glDrawArraysInstanced
Core in version 4.6
Core since version 3.1

glDrawArraysInstanced: draw multiple instances of a range of elements

Function Definition

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

Description

glDrawArraysInstanced behaves identically to glDrawArrays except that primcount​ instances of the range of elements are executed and the value of the internal counter instanceID​ advances for each iteration. instanceID​ is an internal 32-bit integer counter that may be read by a vertex shader as gl_InstanceID.

glDrawArraysInstanced has the same effect as:

    if ( mode or count is invalid )
        generate appropriate error
    else {
        for (int i = 0; i < primcount ; i++) {
            instanceID = i;
            glDrawArrays(mode, first, count);
        }
        instanceID = 0;
    }

Errors

GL_INVALID_ENUM is generated if mode​ is not one of the accepted values.

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.

GL_INVALID_VALUE is generated if count​ or primcount​ are 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.

See Also

glBindVertexArray, glDrawArrays, glDrawArraysIndirect, glDrawArraysInstancedBaseInstance, glMultiDrawArrays, glMultiDrawArraysIndirect

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/.