glEnableVertexAttribArray — Enable or disable a generic vertex attribute array
void glEnableVertexAttribArray( | GLuint index) ; |
void glDisableVertexAttribArray( | GLuint index) ; |
index
Specifies the index of the generic vertex attribute to be enabled or disabled.
glEnableVertexAttribArray
enables the generic vertex attribute array specified by index
. glDisableVertexAttribArray
disables the generic vertex attribute array specified by index
. By default, all generic vertex attribute arrays are disabled. If enabled, the values in the generic vertex attribute array will be accessed and used for rendering when calls are made to vertex array commands such as glDrawArrays, glDrawArraysInstanced, glDrawElements, glDrawElementsInstanced, or glDrawRangeElements.
GL_INVALID_VALUE
is generated if index
is greater than or equal to GL_MAX_VERTEX_ATTRIBS
.
glGet with argument GL_MAX_VERTEX_ATTRIBS
glGetVertexAttrib with arguments index
and GL_VERTEX_ATTRIB_ARRAY_ENABLED
glGetVertexAttribPointerv with arguments index
and GL_VERTEX_ATTRIB_ARRAY_POINTER
glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); // vertex_buffer is retrieved from glGenBuffers glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, index_buffer); // index_buffer is retrieved from glGenBuffers glEnableVertexAttribArray(texcoord_attrib_index); // Attribute indexes were received from calls to glGetAttribLocation, or passed into glBindAttribLocation. glEnableVertexAttribArray(normal_attrib_index); glEnableVertexAttribArray(position_attrib_index); // vertex_stride is the size of bytes of each vertex in the buffer object // vertex_position_offset and kin are the offset in bytes of the position data // in each vertex. For example if your vertex structure is // [ position, texcoord, normal ] then position vertex_position_offset will // have offset 0, vertex_texcoord_offset is 12 (position is 3 * sizeof(float) // bytes large, and texcoord comes just after) and vertex_normal_offset is // 20 = 5 * sizeof(float). GLintptr vertex_texcoord_offset = 3 * sizeof(float); GLintptr vertex_normal_offset = 5 * sizeof(float); GLintptr vertex_position_offset = 0 * sizeof(float); glVertexAttribPointer(texcoord_attrib_index, 2, GL_FLOAT, false, vertex_stride, (GLvoid*)vertex_texcoord_offset); glVertexAttribPointer(normal_attrib_index, 3, GL_FLOAT, false, vertex_stride, (GLvoid*)vertex_normal_offset); glVertexAttribPointer(position_attrib_index, 3, GL_FLOAT, false, vertex_stride, (GLvoid*)vertex_position_offset); // num_vertices is the number of verts in your vertex_data. // index_data is an array of unsigned int offsets into vertex_data. glDrawElements(GL_TRIANGLES, num_vertices, GL_UNSIGNED_INT, NULL); glDisableVertexAttribArray(position_attrib_index); glDisableVertexAttribArray(texcoord_attrib_index); glDisableVertexAttribArray(normal_attrib_index);
nehe.gamedev.net - iOS Lesson 02 - First Triangle
open.gl - Geometry Shaders
open.gl - Textures Objects and Parameters
open.gl - The Graphics Pipeline
open.gl - Transform Feedback
opengl-tutorial.org - Particles / Instancing
opengl-tutorial.org - Tutorial 13 : Normal Mapping
opengl-tutorial.org - Tutorial 2 : The first triangle
opengl-tutorial.org - Tutorial 4 : A Colored Cube
opengl-tutorial.org - Tutorial 8 : Basic shading
OpenGL ES API Version | |||
---|---|---|---|
Function Name | 2.0 | 3.0 | 3.1 |
glEnableVertexAttribArray | ✔ | ✔ | ✔ |
glDisableVertexAttribArray | ✔ | ✔ | ✔ |
glBindAttribLocation, glDrawArrays, glDrawArraysInstanced, glDrawElements, glDrawElementsInstanced, glDrawRangeElements, glVertexAttrib, glVertexAttribPointer
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