GLTEXIMAGE1D(3G) | GLTEXIMAGE1D(3G) |
glTexImage1D - specify a one-dimensional texture image
void glTexImage1D( GLenum target,
GLint level, GLint internalformat, GLsizei width, GLint border, GLenum format, GLenum type, const GLvoid *pixels )
Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable one-dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_1D.
Texture images are defined with glTexImage1D. The arguments describe the parameters of the texture image, such as width, width of the border, level-of-detail number (see glTexParameter), and the internal resolution and used to store the image. The last three arguments describe how the image is represented in memory; they are identical to the pixel formats used for glDrawPixels.
If target is GL_PROXY_TEXTURE_1D, no data is read from pixels, but all of the texture image state is recalculated, checked for consistency, and checked against the implementation's capabilities. If the implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but does not generate an error (see glGetError). To query for an entire mipmap array, use an image array level greater than or equal to 1.
If target is GL_TEXTURE_1D, data is read from pixels as a sequence of signed or unsigned bytes, shorts, or longs, or single-precision floating-point values, depending on type. These values are grouped into sets of one, two, three, or four values, depending on format, to form elements. If type is GL_BITMAP, the data is considered as a string of unsigned bytes (and format must be GL_COLOR_INDEX). Each data byte is treated as eight 1-bit elements, with bit ordering determined by GL_UNPACK_LSB_FIRST (see glPixelStore).
The first element corresponds to the left end of the texture array. Subsequent elements progress left-to-right through the remaining texels in the texture array. The final element corresponds to the right end of the texture array.
format determines the composition of each element in pixels. It can assume one of eleven symbolic values:
If an application wants to store the texture at a certain resolution or in a certain , it can request the resolution and with internalformat. The GL will choose an internal representation that closely approximates that requested by internalformat, but it may not match exactly. (The representations specified by GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, and GL_RGBA must match exactly. The numeric values 1, 2, 3, and 4 may also be used to specify the preceding representations.)
Use the GL_PROXY_TEXTURE_1D target to try out a resolution and update and recompute its best match for the requested storage resolution and . To query this state, call glGetTexLevelParameter. If the texture cannot be accommodated, texture state is set to 0.
A one-component texture image uses only the red component of the RGBA color from pixels. A two-component image uses the R and A values. A three-component image uses the R, G, and B values. A four-component image uses all of the RGBA components.
Texturing has no effect in color index mode.
If the GL_ARB_imaging extension is supported, RGBA elements may also be processed by the imaging pipeline. The following stages may be applied to an RGBA color before color component clamping to the range [0, 1]:
The texture image can be represented by the same data formats as the pixels in a glDrawPixels command, except that GL_STENCIL_INDEX and GL_DEPTH_COMPONENT cannot be used. glPixelStore and glPixelTransfer modes affect texture images in exactly the way they affect glDrawPixels.
GL_PROXY_TEXTURE_1D may be used only if the GL version is 1.1 or greater.
Internal formats other than 1, 2, 3, or 4 may be used only if the GL version is 1.1 or greater.
In GL version 1.1 or greater, pixels may be a null pointer. In this case texture memory is allocated to accommodate a texture of width width. You can then download subtextures to initialize the texture memory. The image is undefined if the program tries to apply an uninitialized portion of the texture image to a primitive.
Formats GL_BGR, and GL_BGRA and types GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are available only if the GL version is 1.2 or greater.
When the GL_ARB_multitexture extension is supported, glTexImage1D specifies the one-dimensional texture for the current texture unit, specified with glActiveTextureARB.
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_1D or GL_PROXY_TEXTURE_1D.
GL_INVALID_ENUM is generated if format is not an
accepted
constant. Format constants other than GL_STENCIL_INDEX and
GL_DEPTH_COMPONENT are accepted.
GL_INVALID_ENUM is generated if type is not a type constant.
GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not GL_COLOR_INDEX.
GL_INVALID_VALUE is generated if level is less than 0.
GL_INVALID_VALUE may be generated if level is greater than log2(max), where max is the returned value of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if internalformat is not 1, 2, 3, 4, or one of the accepted resolution and symbolic constants.
GL_INVALID_VALUE is generated if width is less than 0 or greater than 2 + GL_MAX_TEXTURE_SIZE, or if it cannot be represented as 2^n + 2(border) for some integer value of n.
GL_INVALID_VALUE is generated if border is not 0 or 1.
GL_INVALID_OPERATION is generated if glTexImage1D is executed between the execution of glBegin and the corresponding execution of glEnd.
GL_INVALID_OPERATION is generated if type is one of GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB.
GL_INVALID_OPERATION is generated if type is one of GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and format is neither GL_RGBA nor GL_BGRA.
glGetTexImage
glIsEnabled with argument GL_TEXTURE_1D
glActiveTextureARB, glColorTable, glConvolutionFilter1D, glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, glDrawPixels, glMatrixMode, glPixelStore, glPixelTransfer, glTexEnv, glTexGen, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D, glTexParameter