gluScaleImage()

NAME

gluScaleImage − scale an image to an arbitrary size

SYNOPSIS

GLint gluScaleImage(
        GLenum format,
        GLsizei wIn,
        GLsizei hIn,
        GLenum typeIn,
        const void ∗dataIn,
        GLsizei wOut,
        GLsizei hOut,
        GLenum typeOut,
        GLvoid∗ dataOut );

PARAMETERS

format
Specifies the format of the pixel data. The following symbolic values are valid: GL_COLOR_INDEX, GL_STENCIL_INDEX, GL_DEPTH_COMPONENT, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.

wIn, hIn
Specify the width and height, respectively, of the source image that is scaled.

typeIn
Specifies the data type for dataIn. Must be one of GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, or GL_FLOAT.

dataIn
Specifies a pointer to the source image.

wOut, hOut
Specify the width and height, respectively, of the destination image.

typeOut
Specifies the data type for dataOut. Must be one of GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, or GL_FLOAT.

dataOut
Specifies a pointer to the destination image.

DESCRIPTION

gluScaleImage() scales a pixel image using the appropriate pixel store modes to unpack data from the source image and pack data into the destination image.

When shrinking an image, gluScaleImage() uses a box filter to sample the source image and create pixels for the destination image. When magnifying an image, the pixels from the source image are linearly interpolated to create the destination image.

A return value of 0 indicates success, otherwise a GLU error code is returned (see gluErrorString()).

See the glReadPixels() reference page for a description of the acceptable values for format, typeIn, and typeOut.

ERRORS

GLU_INVALID_VALUE is returned if wIn, hIn, wOut, or hOut are < 0.

GLU_INVALID_ENUM is returned if format, typeIn, or typeOut are not legal.

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