glDrawArraysEXT - render primitives from array data
void glDrawArraysEXT( 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_TRIANGLE_STRIP, GL_TRIANGLE_FAN, GL_TRIANGLES, GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted. first Specifies the starting index in the enabled arrays. count Specifies the number of indices which should be rendered.
glDrawArraysEXT makes it possible to specify multiple geometric primitives with very few subroutine calls. Instead of calling an OpenGL procedure to pass each individual vertex, normal, or color, separate arrays of vertexes, normals, and colors can be prespecified, and used to define a sequence of primitives (all of the same type) with a single call to glDrawArraysEXT. When glDrawArraysEXT is called, count sequential elements from each enabled array are used to construct a sequence of geometric primitives, beginning with element first. mode specifies what kind of primitives are constructed, and how the array elements are used to construct these primitives. If GL_VERTEX_ARRAY_EXT is not enabled, no geometric primitives are generated. Vertex attributes that are modified by glDrawArraysEXT have an unspecified value after glDrawArraysEXT returns. For example, if GL_COLOR_ARRAY_EXT is enabled, the value of the current color is undefined after glDrawArraysEXT executes. Attributes that aren't modified remain well defined. Operation of glDrawArraysEXT is atomic with respect to error generation. If an error is generated, no other operations take place.
glDrawArraysEXT may be included in display lists. If glDrawArraysEXT is entered into a display list, the necessary array data (determined by the array pointers and enables) is also entered into the display list. Because the array pointers and enables are client side state, their values affect display lists when the lists are created, not when the lists are executed. Static array data may be read and cached by the implementation at any time. If static array elements are modified and the arrays are not respecified, the results of any subsequent calls to glDrawArraysEXT are undefined. Although it is not an error to respecify an array between the execution of glBegin and the corresponding execution of glEnd, the result of such respecification is undefined. glDrawArraysEXT is part of the EXT_vertex_array extension, not part of the core GL command set. If "GL_EXT_vertex_array" is included in the string returned by glGetString, when called with argument GL_EXTENSIONS, extension EXT_vertex_array is supported.
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 glDrawArraysEXT is called between the execution of glBegin and the corresponding execution of glEnd.
glArrayElementEXT, glColorPointerEXT, glEdgeFlagPointerEXT, glGetPointervEXT, glIndexPointerEXT, glNormalPointerEXT, glTexCoordPointerEXT, glVertexPointerEXT
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Last Edited: Fri Feb 24, 1995