GLCOPYTEXSUBIMAGE3D(3G)

📦
version 1.1 · 7 versions
, in centos-stream 9

💅 GLCOPYTEXSUBIMAGE3D — the 3G page from the [FIXME: manual] manual, bestie

okay so this is the glow-up of GLCOPYTEXSUBIMAGE3D(3G), and we're making texture subimage copying make sense. no cap, it's giving "copy pixels from the screen into a 3D texture" energy ✨

✨ NAME ✨

glCopyTexSubImage3D, glCopyTextureSubImage3D — copy a three-dimensional texture subimage 🎀

💻 C SPECIFICATION 💻

void glCopyTexSubImage3D(GLenum target, GLint level, GLint xoffset,
                         GLint yoffset, GLint zoffset, GLint x, GLint y,
                         GLsizei width, GLsizei height);

void glCopyTextureSubImage3D(GLuint texture, GLint level, GLint xoffset,
                             GLint yoffset, GLint zoffset, GLint x, GLint y,
                             GLsizei width, GLsizei height);

🌸 PARAMETERS 🌸

  • target — specifies the target to which the texture object is bound for the glCopyTexSubImage3D function. Must be GL_TEXTURE_3D or GL_TEXTURE_2D_ARRAY.
  • texture — specifies the texture object name for the glCopyTextureSubImage3D function. iykyk, it's the texture bestie's name 🫶
  • 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.
  • zoffset — specifies a texel offset in the z direction within the texture array. yes, z is in its main character era 💅
  • x, y — specify the window coordinates of the lower left corner of the rectangular region of pixels to be copied.
  • width — specifies the width of the texture subimage.
  • height — specifies the height of the texture subimage.

🦋 DESCRIPTION 🦋

okay so glCopyTexSubImage3D and glCopyTextureSubImage3D replace a rectangular portion of a three-dimensional or two-dimensional array texture image with pixels from the current GL_READ_BUFFER (rather than from main memory, as is the case for glTexSubImage3D()). it's giving "copy from the screen, not from CPU memory" energy ✨

The screen-aligned pixel rectangle with lower left corner at (x, y) and with width width and height height replaces the portion of the texture array with x indices xoffset through xoffset + width - 1, inclusive, and y indices yoffset through yoffset + height - 1, inclusive, at z index zoffset and at the mipmap level specified by level.

The pixels in the rectangle are processed exactly as if glReadPixels() had been called, but the process stops just before final conversion. At this point, all pixel component values are clamped to the range 0 to 1 and then converted to the texture's internal format for storage in the texel array. (yes bestie, clamped, converted, stored — the whole glow-up 💅)

The destination rectangle in the texture array may not include any texels outside 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. zero-size? valid, but literally does nothing 🙈

If any of the pixels within the specified rectangle of the current GL_READ_BUFFER are outside the read window associated with the current rendering context, then the values obtained for those pixels are undefined. undefined means do not trust those pixel values, no cap 💀

No change is made to the internalformat, width, height, depth, or border parameters of the specified texture array or to texel values outside the specified subregion. it only touches the subregion you asked for, periodt ✨

🎀 NOTES 🎀

glPixelStore() modes affect texture images. that's the whole note, but it matters bestie 🫶

🔥 ERRORS 🔥

  • GL_INVALID_ENUM is generated by glCopyTexSubImage3D if target is not GL_TEXTURE_3D, GL_TEXTURE_2D_ARRAY or GL_TEXTURE_CUBE_MAP_ARRAY.
  • GL_INVALID_OPERATION is generated by glCopyTextureSubImage3D if the effective target is not GL_TEXTURE_3D, GL_TEXTURE_2D_ARRAY, GL_TEXTURE_CUBE_MAP_ARRAY or GL_TEXTURE_CUBE_MAP.
  • GL_INVALID_FRAMEBUFFER_OPERATION is generated if the object bound to GL_READ_FRAMEBUFFER_BINDING is not framebuffer complete.
  • GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage3D() or glTexStorage3D() operation.
  • GL_INVALID_OPERATION is generated by glCopyTextureSubImage3D if texture is not the name of an existing texture object.
  • GL_INVALID_VALUE is generated if level is less than 0.
  • GL_INVALID_VALUE may be generated if level > log 2 max, where max is the returned value of GL_MAX_3D_TEXTURE_SIZE if target is GL_TEXTURE_3D or the returned value of GL_MAX_ARRAY_TEXTURE_LAYERS if target is GL_TEXTURE_2D_ARRAY.
  • GL_INVALID_VALUE is generated if xoffset < 0, xoffset + width > w, yoffset < 0, yoffset + height > h, zoffset < 0, or zoffset + 1 > d, where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, d is the GL_TEXTURE_DEPTH and of the texture image being modified. Note that w, h, and d include twice the border width.
  • GL_INVALID_OPERATION is generated if:
    • the read buffer is GL_NONE, or
    • the value of GL_READ_FRAMEBUFFER_BINDING is non-zero, and:
      • the read buffer selects an attachment that has no image attached, or
      • the effective value of GL_SAMPLE_BUFFERS for the read framebuffer is one.

👑 ASSOCIATED GETS 👑

glGetTexImage()

🌈 VERSION SUPPORT 🌈

the original table's OpenGL Version columns are 2.0, 2.1, 3.0, 3.1, 3.2, 3.3, 4.0, 4.1, 4.2, 4.3, 4.4, and 4.5. the rows are Function / Feature Name:

  • glCopyTexSubImage3D — ✔ in 2.0; ✔ in 2.1; ✔ in 3.0; ✔ in 3.1; ✔ in 3.2; ✔ in 3.3; ✔ in 4.0; ✔ in 4.1; ✔ in 4.2; ✔ in 4.3; ✔ in 4.4; ✔ in 4.5.
  • glCopyTextureSubImage3D — - in 2.0; - in 2.1; - in 3.0; - in 3.1; - in 3.2; - in 3.3; - in 4.0; - in 4.1; - in 4.2; - in 4.3; - in 4.4; ✔ in 4.5.

🧚 SEE ALSO 🧚

glCopyTexImage1D(), glCopyTexImage2D(), glCopyTexSubImage1D(), glCopyTexSubImage2D(), glPixelStore(), glReadBuffer(), glTexImage1D(), glTexImage2D(), glTexImage3D(), glTexParameter(), glTexSubImage1D(), glTexSubImage2D(), glTexSubImage3D()

Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2012-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

Copyright © 2014 Khronos Group

okay bye bestie 💋 this page is from [FIXME: source], dated 08/09/2021, and it's the GLCOPYTEXSUBIMAGE3D(3G) page. mwah 🫶

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