Tao.OpenGl SDK Documentation

Glu.gluBuild2DMipmapLevels Method (Int32, Int32, Int32, Int32, Int32, Int32, Int32, Int32, Int32, Byte[])

Builds a subset of two-dimensional mipmap levels.

[Visual Basic]
Overloads Public Shared Function gluBuild2DMipmapLevels( _
   ByVal target As Integer, _
   ByVal internalFormat As Integer, _
   ByVal width As Integer, _
   ByVal height As Integer, _
   ByVal format As Integer, _
   ByVal type As Integer, _
   ByVal level As Integer, _
   ByVal min As Integer, _
   ByVal max As Integer, _
   ByVal data As Byte() _
) As Integer
[C#]
public static int gluBuild2DMipmapLevels(
   int target,
   int internalFormat,
   int width,
   int height,
   int format,
   int type,
   int level,
   int min,
   int max,
   byte[] data
);

Parameters

target
Specifies the target texture. Must be GL_TEXTURE_2D.
internalFormat
Requests the internal storage format of the texture image. Must be 1, 2, 3, 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_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_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, in pixels, of the texture image. Should be a power of 2.
height
Specifies the height, in pixels, of the texture image. Should be a power of 2.
format
Specifies the format of the pixel data. Must be one of GL_COLOR_INDEX, GL_DEPTH_COMPONENT, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_BGR, GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
type
Specifies the data type for data. Must be one of 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 or GL_UNSIGNED_INT_2_10_10_10_REV.
level
Specifies the mipmap level of the image data.
min
Specifies the minimum mipmap level to pass to glTexImage2D.
max
Specifies the maximum mipmap level to pass to glTexImage2D.
data
Specifies a pointer to the image data in memory.

Return Value

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

Remarks

gluBuild2DMipmapLevels builds a subset of prefiltered two-dimensional texture maps of decreasing resolutions called a mipmap. This is used for the antialiasing of texture mapped primitives.

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

A series of mipmap levels from min to max is built by decimating data in half along both dimensions until size 1×1 is reached. At each level, each texel in the halved mipmap level is an average of the corresponding four texels in the larger mipmap level. (In the case of rectangular images, the decimation will ultimately reach an N×1 or 1×N configuration. Here, two texels are averaged instead.) glTexImage2D is called to load these mipmap levels from min to max. If max is larger than the highest mipmap level for the texture of the specified size, then a GLU error code is returned (see gluErrorString) and nothing is loaded.

For example, if level is 2 and width is 16 and height is 8, the following levels are possible: 16×8, 8×4, 4×2, 2×1, 1×1. These correspond to levels 2 through 6 respectively. If min is 3 and max is 5, then only mipmap levels 8×4, 4×2 and 2×1 are loaded. However, if max is 7 then an error is returned and nothing is loaded since max is larger than the highest mipmap level which is, in this case, 6.

The highest mipmap level can be derived from the formula log2(max(width,height)*(2^level)).

See the glTexImage2D reference page for a description of the acceptable values for format parameter. See the glDrawPixels reference page for a description of the acceptable values for type parameter.

NOTES

gluBuild2DMipmapLevels is only available if the GLU version is 1.3 or greater.

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 only available if the GL version is 1.2 or greater.

ERRORS

GLU_INVALID_VALUE is returned if level > min, min < 0, max < min or max is > the highest mipmap level for data.

GLU_INVALID_VALUE is returned if width or height is < 1.

GLU_INVALID_ENUM is returned if internalFormat, format, or type is not legal.

GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_BYTE_3_3_2 or GL_UNSIGNED_BYTE_2_3_3_REV and format is not GL_RGB.

GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_SHORT_5_6_5 or GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB.

GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_SHORT_4_4_4_4 or GL_UNSIGNED_SHORT_4_4_4_4_REV and format is neither GL_RGBA nor GL_BGRA.

GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_SHORT_5_5_5_1 or GL_UNSIGNED_SHORT_1_5_5_5_REV and format is neither GL_RGBA nor GL_BGRA.

GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_INT_8_8_8_8 or GL_UNSIGNED_INT_8_8_8_8_REV and format is neither GL_RGBA nor GL_BGRA.

GLU_INVALID_OPERATION is returned if type is 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.

See Also

Glu Class | Tao.OpenGl Namespace | Glu.gluBuild2DMipmapLevels Overload List | glDrawPixels | glGetTexImage | glGetTexLevelParameteriv | glTexImage1D | glTexImage2D | glTexImage3D | gluBuild1DMipmapLevels | gluBuild1DMipmaps | gluBuild2DMipmaps | gluBuild3DMipmapLevels | gluBuild3DMipmaps | gluErrorString