%mathent; ]> 1991-2006 Silicon Graphics, Inc. 2010-2014 Khronos Group glTexImage2D 3G glTexImage2D specify a two-dimensional texture image void glTexImage2D GLenum target GLint level GLint internalFormat GLsizei width GLsizei height GLint border GLenum format GLenum type const GLvoid * data target Specifies the target texture. Must be GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z. level Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image. internalFormat Specifies the number of color components in the texture. Must be one of base internal formats given in Table 1, or one of the sized internal formats given in Table 2, below. width Specifies the width of the texture image. All implementations support texture images that are at least 2048 texels wide. height Specifies the height of the texture image. All implementations support texture images that are at least 2048 texels high. border This value must be 0. format Specifies the format of the pixel data. The following symbolic values are accepted: GL_RED, GL_RED_INTEGER, GL_RG, GL_RG_INTEGER, GL_RGB, GL_RGB_INTEGER, GL_RGBA, GL_RGBA_INTEGER, GL_DEPTH_COMPONENT, GL_DEPTH_STENCIL, GL_LUMINANCE_ALPHA, GL_LUMINANCE, and GL_ALPHA. type Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_HALF_FLOAT, GL_FLOAT, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_INT_2_10_10_10_REV, GL_UNSIGNED_INT_10F_11F_11F_REV, GL_UNSIGNED_INT_5_9_9_9_REV, GL_UNSIGNED_INT_24_8, and GL_FLOAT_32_UNSIGNED_INT_24_8_REV. data Specifies a pointer to the image data in memory. Texturing allows elements of an image array to be read by shaders. To define texture images, call glTexImage2D. The arguments describe the parameters of the texture image, such as height, width, width of the border, level-of-detail number (see glTexParameter), and number of color components provided. The last three arguments describe how the image is represented in memory. If target is GL_TEXTURE_2D or one of the GL_TEXTURE_CUBE_MAP targets, data is read from data 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 a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a texture image is specified, data is treated as a byte offset into the buffer object's data store. The first element corresponds to the lower left corner of the texture image. Subsequent elements progress left-to-right through the remaining texels in the lowest row of the texture image, and then in successively higher rows of the texture image. The final element corresponds to the upper right corner of the texture image. format determines the composition of each element in data. It can assume one of these symbolic values: GL_RED Each element is a single red component. For fixed point normalized components, the GL converts it to floating point, clamps to the range [0,1], and assembles it into an RGBA element by attaching 0.0 for green and blue, and 1.0 for alpha. GL_RED_INTEGER Each element is a single red component. The GL performs assembles it into an RGBA element by attaching 0 for green and blue, and 1 for alpha. GL_RG Each element is a red/green double. For fixed point normalized components, the GL converts each component to floating point, clamps to the range [0,1], and assembles them into an RGBA element by attaching 0.0 for blue, and 1.0 for alpha. GL_RG Each element is a red/green double. The GL assembles them into an RGBA element by attaching 0 for blue, and 1 for alpha. GL_RGB Each element is an RGB triple. For fixed point normalized components, the GL converts each component to floating point, clamps to the range [0,1], and assembles them into an RGBA element by attaching 1.0 for alpha. GL_RGB_INTEGER Each element is an RGB triple. The GL assembles them into an RGBA element by attaching 1 for alpha. GL_RGBA Each element contains all four components. For fixed point normalized components, the GL converts each component to floating point and clamps them to the range [0,1]. GL_RGBA_INTEGER Each element contains all four components. GL_DEPTH_COMPONENT Each element is a single depth value. The GL converts it to floating point, and clamps to the range [0,1]. GL_DEPTH_STENCIL Each element is a pair of depth and stencil values. The depth component of the pair is interpreted as in GL_DEPTH_COMPONENT. The stencil component is interpreted based on specified the depth + stencil internal format. GL_LUMINANCE_ALPHA Each element is an luminance/alpha double. The GL converts each component to floating point, clamps to the range [0,1], and assembles them into an RGBA element by placing the luminance value in the red, green and blue channels. GL_LUMINANCE Each element is a single luminance component. The GL converts it to floating point, clamps to the range [0,1], and assembles it into an RGBA element by placing the luminance value in the red, green and blue channels, and attaching 1.0 to the alpha channel. GL_ALPHA Each element is a single alpha component. The GL converts it to floating point, clamps to the range [0,1], and assembles it into an RGBA element by placing attaching 0.0 to the red, green and blue channels. If an application wants to store the texture at a certain resolution or in a certain format, it can request the resolution and format with internalFormat. The GL will choose an internal representation with least the internal component sizes, and exactly the component types shown for that format, although it may not match exactly. internalFormat may be one of the unsized (base) internal formats shown, together with valid format and type combinations, in Table 1, below internalFormat may also be one of the sized internal formats shown, together with valid format and type combinations, in Table 2, below If the internalFormat parameter is GL_SRGB8, or GL_SRGB8_ALPHA8, the texture is treated as if the red, green, or blue components are encoded in the sRGB color space. Any alpha component is left unchanged. The conversion from the sRGB encoded component c s to a linear component c l is: c l = { c s 12.92 if c s ≤ 0.04045 ( c s + 0.055 1.055 ) 2.4 if c s > 0.04045 Assume c s is the sRGB component in the range [0,1]. A one-component texture image uses only the red component of the RGBA color extracted from data. A two-component image uses the R and G values. A three-component image uses the R, G, and B values. A four-component image uses all of the RGBA components. Image-based shadowing can be enabled by comparing texture r coordinates to depth texture values to generate a boolean result. See glTexParameter for details on texture comparison. The glPixelStorei mode affects texture images. data may be a null pointer. In this case, texture memory is allocated to accommodate a texture of width width and height height. You can then download subtextures to initialize this texture memory. The image is undefined if the user tries to apply an uninitialized portion of the texture image to a primitive. glTexImage2D specifies the two-dimensional texture for the texture object bound to the current texture unit, specified with glActiveTexture. GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z. GL_INVALID_ENUM is generated if target is one of the six cube map 2D image targets and the width and height parameters are not equal. GL_INVALID_ENUM is generated if type is not a type constant. GL_INVALID_VALUE is generated if width is less than 0 or greater than GL_MAX_TEXTURE_SIZE. GL_INVALID_VALUE is generated if level is less than 0. GL_INVALID_VALUE may be generated if level is greater than log 2 ⁡ max , where max is the returned value of GL_MAX_TEXTURE_SIZE. GL_INVALID_VALUE is generated if internalFormat is not one of the accepted resolution and format symbolic constants. GL_INVALID_VALUE is generated if width or height is less than 0 or greater than GL_MAX_TEXTURE_SIZE. GL_INVALID_VALUE is generated if border is not 0. GL_INVALID_OPERATION is generated if the combination of internalFormat, format and type is not one of those in the tables above. GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object's data store is currently mapped. GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the data would be unpacked from the buffer object such that the memory reads required would exceed the data store size. GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and data is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type. glGet with argument GL_PIXEL_UNPACK_BUFFER_BINDING glTexImage2D glActiveTexture, glCopyTexImage2D, glCopyTexSubImage2D, glCopyTexSubImage3D, glPixelStorei, glTexImage3D, glTexStorage2D, glTexStorage3D, glTexSubImage2D, glTexSubImage3D, glTexParameter Copyright 1991-2006 Silicon Graphics, Inc. Copyright 2010-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.