GLTEXSUBIMAGE2D(3G)

💖 GLTEXSUBIMAGE2D(3G) 💖

Bestie, welcome to the GLTEXSUBIMAGE2D(3G) manual page — the one and only glTexSubImage2D glow-up. This is about specifying a two-dimensional texture subimage, and yes, we're gonna get through every single flag together. 💅✨

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🌸 NAME 🌸

glTexSubImage2D — specify a two-dimensional texture subimage.

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🦋 C SPECIFICATION 🦋

void glTexSubImage2D( GLenum target,
                      GLint level,
                      GLint xoffset,
                      GLint yoffset,
                      GLsizei width,
                      GLsizei height,
                      GLenum format,
                      GLenum type,
                      const GLvoid *pixels )

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🎀 PARAMETERS 🎀

• target — specifies the target texture. It must be GL_TEXTURE_2D. No side-eyeing other targets, bestie. 👀
• level — specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
• xoffset — specifies a texel offset in the x direction within the texture array.
• yoffset — specifies a texel offset in the y direction within the texture array.
• width — specifies the width of the texture subimage.
• height — specifies the height of the texture subimage.
• format — specifies the [word omitted in the original page] of the pixel data. The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
• type — specifies the data type of the pixel data. The following symbolic values are accepted: 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.
• pixels — specifies a pointer to the image data in memory. It's giving "here's the actual pixel tea." 🍓

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🧚 DESCRIPTION 🧚

Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable two-dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_2D.

glTexSubImage2D redefines a contiguous subregion of an existing two-dimensional texture image. The texels referenced by pixels replace the portion of the existing texture array with x indices xoffset and xoffset+width−1, inclusive, and y indices yoffset and yoffset+height−1, inclusive. This region may not include any texels outside the range of the texture array as it was originally specified. It is not an error to specify a subtexture with zero width or height, but such a specification has no effect.

Lowkey important: that subregion has to stay inside the texture array as it was originally specified. No stretching outside the lines, bestie. 💀

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✨ NOTES ✨

• glTexSubImage2D is available only if the GL version is 1.1 or greater.
• Texturing has no effect in color index mode.
• glPixelStore and glPixelTransfer modes affect texture images in exactly the way they affect glDrawPixels.
• 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 available only if the GL version is 1.2 or greater.
• When the GL_ARB_multitexture extension is supported, glTexSubImage2D specifies a two-dimensional sub texture for the current texture unit, specified with glActiveTextureARB.
• When the GL_ARB_imaging extension is supported, the RGBA components specified in pixels may be processed by the imaging pipeline. See glTexImage1D for specific details.

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🫶 ERRORS 🫶

• GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D.
• GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage2D operation.
• GL_INVALID_VALUE is generated if level is less than 0.
• GL_INVALID_VALUE may be generated if level is greater than log2max, where max is the returned value of GL_MAX_TEXTURE_SIZE.
• GL_INVALID_VALUE is generated if xoffset<−b, (xoffset+width)>(w−b), yoffset<−b, or (yoffset+height)>(h−b), where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, and b is the border width of the texture image being modified. Note that w and h include twice the border width.
• GL_INVALID_VALUE is generated if width or height is less than 0.
• GL_INVALID_ENUM is generated if format is not an accepted constant.
• 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_OPERATION is generated if glTexSubImage2D is executed between the execution of glBegin and the corresponding execution of glEnd.
• GL_INVALID_OPERATION is generated if type 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 format is not GL_RGB.
• GL_INVALID_OPERATION is generated if type 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 format is neither GL_RGBA nor GL_BGRA.

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👑 ASSOCIATED GETS 👑

• glGetTexImage
• glIsEnabled with argument GL_TEXTURE_2D

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🌈 SEE ALSO 🌈

• glActiveTextureARB(3G)
• glCopyTexImage1D(3G)
• glCopyTexImage2D(3G)
• glCopyTexSubImage1D(3G)
• glCopyTexSubImage2D(3G)
• glCopyTexSubImage3D(3G)
• glDrawPixels(3G)
• glPixelStore(3G)
• glPixelTransfer(3G)
• glTexEnv(3G)
• glTexGen(3G)
• glTexImage1D(3G)
• glTexImage2D(3G)
• glTexImage3D(3G)
• glTexSubImage1D(3G)
• glTexSubImage3D(3G)
• glTexParameter(3G)

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That's the whole page, bestie — manual/source tag: GLTEXSUBIMAGE2D(3G), and the original footer has no date listed, so we are not inventing one. Periodt. 💖✨🎀