Name
glBindBuffer — bind a named buffer object
C Specification
void glBindBuffer( | GLenum | target, |
| GLuint | buffer); |
Parameters
target- Specifies the target to which the buffer object is bound. The symbolic constant must be
GL_ARRAY_BUFFER,GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER, or GL_PIXEL_UNPACK_BUFFER.
buffer- Specifies the name of a buffer object.
Description
glBindBuffer lets you create or use a named buffer object. Calling
glBindBuffer with
target set to
GL_ARRAY_BUFFER,
GL_ELEMENT_ARRAY_BUFFER,
GL_PIXEL_PACK_BUFFER or
GL_PIXEL_UNPACK_BUFFER and
buffer set to the name of the new buffer object binds the buffer object name to the target. When a buffer object is bound to a target, the previous binding for that target is automatically broken.
Buffer object names are unsigned integers. The value zero is reserved, but there is no default buffer object for each buffer object target. Instead,
buffer set to zero effectively unbinds any buffer object previously bound, and restores client memory usage for that buffer object target. Buffer object names and the corresponding buffer object contents are local to the shared display-list space (see
glXCreateContext) of the current GL rendering context; two rendering contexts share buffer object names only if they also share display lists.
You may use
glGenBuffers to generate a set of new buffer object names.
The state of a buffer object immediately after it is first bound is an unmapped zero-sized memory buffer with
GL_READ_WRITE access and
GL_STATIC_DRAW usage.
While a non-zero buffer object name is bound, GL operations on the target to which it is bound affect the bound buffer object, and queries of the target to which it is bound return state from the bound buffer object. While buffer object name zero is bound, as in the initial state, attempts to modify or query state on the target to which it is bound generates an
GL_INVALID_OPERATION error.
When vertex array pointer state is changed, for example by a call to
glNormalPointer, the current buffer object binding (
GL_ARRAY_BUFFER_BINDING) is copied into the corresponding client state for the vertex array type being changed, for example
GL_NORMAL_ARRAY_BUFFER_BINDING. While a non-zero buffer object is bound to the
GL_ARRAY_BUFFER target, the vertex array pointer parameter that is traditionally interpreted as a pointer to client-side memory is instead interpreted as an offset within the buffer object measured in basic machine units.
While a non-zero buffer object is bound to the
GL_ELEMENT_ARRAY_BUFFER target, the indices parameter of
glDrawElements,
glDrawRangeElements, or
glMultiDrawElements that is traditionally interpreted as a pointer to client-side memory is instead interpreted as an offset within the buffer object measured in basic machine units.
While a non-zero buffer object is bound to the
GL_PIXEL_PACK_BUFFER target, the following commands are affected:
glGetCompressedTexImage,
glGetConvolutionFilter,
glGetHistogram,
glGetMinmax,
glGetPixelMap,
glGetPolygonStipple,
glGetSeparableFilter,
glGetTexImage, and
glReadPixels. The pointer parameter that is traditionally interpreted as a pointer to client-side memory where the pixels are to be packed is instead interpreted as an offset within the buffer object measured in basic machine units.
While a non-zero buffer object is bound to the
GL_PIXEL_UNPACK_BUFFER target, the following commands are affected:
glBitmap,
glColorSubTable,
glColorTable,
glCompressedTexImage1D,
glCompressedTexImage2D,
glCompressedTexImage3D,
glCompressedTexSubImage1D,
glCompressedTexSubImage2D,
glCompressedTexSubImage3D,
glConvolutionFilter1D,
glConvolutionFilter2D,
glDrawPixels,
glPixelMap,
glPolygonStipple,
glSeparableFilter2D,
glTexImage1D,
glTexImage2D,
glTexImage3D,
glTexSubImage1D,
glTexSubImage2D, and
glTexSubImage3D. The pointer parameter that is traditionally interpreted as a pointer to client-side memory from which the pixels are to be unpacked is instead interpreted as an offset within the buffer object measured in basic machine units.
A buffer object binding created with
glBindBuffer remains active until a different buffer object name is bound to the same target, or until the bound buffer object is deleted with
glDeleteBuffers.
Once created, a named buffer object may be re-bound to any target as often as needed. However, the GL implementation may make choices about how to optimize the storage of a buffer object based on its initial binding target.
Notes
glBindBuffer is available only if the GL version is 1.5 or greater.
GL_PIXEL_PACK_BUFFER and
GL_PIXEL_UNPACK_BUFFER are available only if the GL version is 2.1 or greater.
Errors
GL_INVALID_ENUM is generated if
target is not one of the allowable values.
GL_INVALID_OPERATION is generated if
glBindBuffer is executed between the execution of
glBegin and the corresponding execution of
glEnd.
Associated Gets
glGet with argument
GL_ARRAY_BUFFER_BINDING
glGet with argument
GL_ELEMENT_ARRAY_BUFFER_BINDING
glGet with argument
GL_PIXEL_PACK_BUFFER_BINDING
glGet with argument
GL_PIXEL_UNPACK_BUFFER_BINDING
Copyright
Copyright
© 2005 Addison-Wesley. 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/.
Example
1
GLfloat afVertices[] = { -0.4f,-0.4f,0.0f, // Position
2
0.4f ,-0.4f,0.0f,
3
0.0f ,0.4f ,0.0f};
4
GLuint ui32Vbo;
5// Generate and Bind the vertex buffer object (VBO)
6glGenBuffers(1, &ui32Vbo);
7glBindBuffer(GL_ARRAY_BUFFER, ui32Vbo);
8
9unsigned int uiSize = 3 * (sizeof(GLfloat) * 3);
10glBufferData(GL_ARRAY_BUFFER, uiSize, afVertices, GL_STATIC_DRAW);
11
12// Frame
13glClear(GL_COLOR_BUFFER_BIT);
14
15// First gets the location of that variable in the shader using its name
16 int i32Location = glGetUniformLocation(uiProgramObject, "myPMVMatrix");
17glUniformMatrix4fv( i32Location, 1, GL_FALSE, pfIdentity);
18
19glEnableVertexAttribArray(VERTEX_ARRAY);
20glVertexAttribPointer(VERTEX_ARRAY, 3, GL_FLOAT, GL_FALSE, 0, 0);
21
22glDrawArrays(GL_TRIANGLES, 0, 3);
23eglSwapBuffers(eglDisplay, eglSurface);
