fglConvolutionFilter1D(3G)
fglConvolutionFilter1D - define a one-dimensional convolution filter
As shipped in IRIX 6.5.22. Added in IRIX 6.5.15.
NAME fglConvolutionFilter1D - define a one-dimensional convolution filter FORTRAN SPECIFICATION SUBROUTINE fglConvolutionFilter1D( INTEGER*4 target, INTEGER*4 internalformat, INTEGER*4 width, INTEGER*4 format, INTEGER*4 type, CHARACTER*8 image ) PARAMETERS target Must be GL_CONVOLUTION_1D. internalformat The internal format of the convolution filter kernel. The allowable values are GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB, 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 The width of the pixel array referenced by image. format The format of the pixel data in image. The allowable values are GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_ABGR_EXT, GL_LUMINANCE, and GL_LUMINANCE_ALPHA. type The type of the pixel data in image. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, 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 accepted. image Pointer to a one-dimensional array of pixel data that is processed to build the convolution filter kernel. DESCRIPTION fglConvolutionFilter1D builds a one-dimensional convolution filter kernel from an array of pixels. The pixel array specified by width, format, type, and image is extracted from memory and processed just as if fglDrawPixels were called, but processing stops after the final expansion to RGBA is completed. The R, G, B, and A components of each pixel are next scaled by the four 1D GL_CONVOLUTION_FILTER_SCALE parameters and biased by the four 1D GL_CONVOLUTION_FILTER_BIAS parameters. (The scale and bias parameters are set by fglConvolutionParameter using the GL_CONVOLUTION_1D target and the names GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS. The parameters themselves are vectors of four values that are applied to red, green, blue, and alpha, in that order.) The R, G, B, and A values are not clamped to [0,1] at any time during this process. Each pixel is then converted to the internal format specified by internalformat. This conversion simply maps the component values of the pixel (R, G, B, and A) to the values included in the internal format (red, green, blue, alpha, luminance, and intensity). The mapping is as follows: _______________________________________________________________________ Internal Format Red Green Blue Alpha Luminance Intensity _______________________________________________________________________ GL_ALPHA A GL_LUMINANCE R GL_LUMINANCE_ALPHA A R GL_INTENSITY R GL_RGB R G B GL_RGBA R G B A _______________________________________________________________________ The red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are stored in floating-point rather than integer format. They form a one-dimensional filter kernel image indexed with coordinate i such that i starts at 0 and increases from left to right. Kernel location i is derived from the ith pixel, counting from 0. Note that after a convolution is performed, the resulting color components are also scaled by their corresponding GL_POST_CONVOLUTION_c_SCALE parameters and biased by their corresponding GL_POST_CONVOLUTION_c_BIAS parameters (where c takes on the values RED, GREEN, BLUE, and ALPHA). These parameters are set by fglPixelTransfer. NOTES fglConvolutionFilter1D is present only if GL_ARB_imaging is returned when fglGetString is called with an argument of GL_EXTENSIONS. GL_ABGR_EXT is valid only if the EXT_abgr extension is supported. ERRORS GL_INVALID_ENUM is generated if target is not GL_CONVOLUTION_1D. GL_INVALID_ENUM is generated if internalformat is not one of the allowable values. GL_INVALID_VALUE is generated if width is less than zero or greater than the maximum supported value. This value may be queried with fglGetConvolutionParameter using target GL_CONVOLUTION_1D and name GL_MAX_CONVOLUTION_WIDTH. GL_INVALID_ENUM is generated if format is not one of the allowable values. GL_INVALID_ENUM is generated if type is not one of the allowable values. GL_INVALID_OPERATION is generated if fglConvolutionFilter1D is executed between the execution of fglBegin and the corresponding execution of fglEnd. GL_INVALID_OPERATION is generated if format 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 type is not GL_RGB. GL_INVALID_OPERATION is generated if format 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 type is not GL_RGBA, GL_BGRA or GL_ABGR_EXT. ASSOCIATED GETS fglGetConvolutionParameter, fglGetConvolutionFilter SEE ALSO fglConvolutionFilter2D, fglSeparableFilter2D, fglConvolutionParameter, fglPixelTransfer