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GLTEXIMAGE1D() GLTEXIMAGE1D() NAME glTexImage1D - specify a one-dimensional texture image C SPECIFICATION void glTexImage1D( GLenum target, GLint level, GLint internalformat, GLsizei width, GLint border, GLenum format, GLenum type, const GLvoid *pixels ) delim $$ PARAMETERS target Specifies the target texture. Must be GL_TEXTURE_1D or GL_PROXY_TEXTURE_1D. 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 tex- ture. Must be 1, 2, 3, or 4, or one of the following symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMI- NANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_AL- PHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_IN- TENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_RGB, GL_R3_G3_B2, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16. width Specifies the width of the texture image. Must be $2 sup n + 2 ( "border" )$ for some integer $n$. All im- plementations support texture images that are at least 64 texels wide. The height of the 1D texture image is 1. border Specifies the width of the border. Must be either 0 or 1. format Specifies the format of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_LUMI- NANCE, and GL_LUMINANCE_ALPHA. type Specifies the data type of the pixel data. The follow- ing symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UN- SIGNED_INT, GL_INT, and GL_FLOAT. pixels Specifies a pointer to the image data in memory. DESCRIPTION Texturing maps a portion of a specified texture image onto each graphi- cal 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 bor- der, level-of-detail number (see glTexParameter), and the internal res- olution and format 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 imple- mentation 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 float- ing-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_UN- PACK_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 nine symbolic values: GL_COLOR_INDEX Each element is a single value, a color index. The GL con- verts it to fixed point (with an unspecified number of zero bits to the right of the binary point), shifted left or right depending on the value and sign of GL_INDEX_SHIFT, and added to GL_INDEX_OFFSET (see glPixelTransfer). The resulting in- dex is converted to a set of color components using the GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1]. GL_RED Each element is a single red component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for green and blue, and 1 for alpha. Each compo- nent is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer). GL_GREEN Each element is a single green component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and blue, and 1 for alpha. Each compo- nent is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer). GL_BLUE Each element is a single blue component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and green, and 1 for alpha. Each compo- nent is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer). GL_ALPHA Each element is a single alpha component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer). GL_RGB Each element is an RGB triple. The GL converts it to float- ing point and assembles it into an RGBA element by attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer). GL_RGBA Each element contains all four components. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer). GL_LUMINANCE Each element is a single luminance value. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue and attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer). GL_LUMINANCE_ALPHA Each element is a luminance/alpha pair. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE, added to the signed bias GL_c_BIAS, and clamped to the range [0,1] (see glPixelTransfer). 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 in- ternalformat. 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_LU- MINANCE_ALPHA, GL_RGB, and GL_RGBA must match exactly. The numeric val- ues 1, 2, 3, and 4 may also be used to specify the preceding represen- tations.) Use the GL_PROXY_TEXTURE_1D target to try out a resolution and format. The implementation will update and recompute its best match for the re- quested storage resolution and format. To query this state, call glGet- TexLevelParameter. 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 extracted 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. NOTES Texturing has no effect in color index mode. 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 glDrawPix- els. GL_PROXY_TEXTURE_1D may only be used if the GL version is 1.1 or greater. Internal formats other than 1, 2, 3, or 4 may only be used 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 unini- tialized portion of the texture image to a primitive. ERRORS 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 format con- stant. Format constants other than GL_STENCIL_INDEX and GL_DEPTH_COM- PONENT 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 $log sub 2$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 format 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 $2 sup n + 2("border")$ 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. ASSOCIATED GETS glGetTexImage glIsEnabled with argument GL_TEXTURE_1D SEE ALSO glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glDrawPixels, glPixelStore, glPixelTransfer, gl- TexEnv, glTexGen, glTexImage2D, glTexSubImage1D, glTexSubImage2D, glT- exParameter GLTEXIMAGE1D()
NAME | C SPECIFICATION | PARAMETERS | DESCRIPTION | NOTES | ERRORS | ASSOCIATED GETS | SEE ALSO
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