GLREADBUFFER(3G)

🌈 glReadBuffer — select a color buffer source for pixels 🌈

okay so bestie, this is the 3G manual page for glReadBuffer, and it's literally the glow-up for picking which color buffer future pixel commands read from. no cap, every flag and caveat is below 💖

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🌸 NAME 🌸

glReadBuffer — select a color buffer source for pixels ✨

🧚 C SPECIFICATION 🧚

void glReadBuffer( GLenum mode )

🎀 PARAMETERS 🎀

• mode — specifies a color buffer. The accepted values are GL_FRONT_LEFT, GL_FRONT_RIGHT, GL_BACK_LEFT, GL_BACK_RIGHT, GL_FRONT, GL_BACK, GL_LEFT, GL_RIGHT, and GL_AUXi, where i is between 0 and GL_AUX_BUFFERS -1.

🦋 DESCRIPTION 🦋

okay so glReadBuffer specifies a color buffer as the source for subsequent glReadPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, and glCopyPixels commands. It's giving “choose your source buffer, main character energy” 💅

mode accepts one of twelve or more predefined values. (GL_AUX0 through GL_AUX3 are always defined.) In a fully configured system, GL_FRONT, GL_LEFT, and GL_FRONT_LEFT all name the front left buffer, GL_FRONT_RIGHT and GL_RIGHT name the front right buffer, and GL_BACK_LEFT and GL_BACK name the back left buffer. Slay, but make sure it actually exists 👑

Nonstereo double-buffered configurations have only a front left and a back left buffer. Single-buffered configurations have a front left and a front right buffer if stereo, and only a front left buffer if nonstereo. It is an error to specify a nonexistent buffer to glReadBuffer. So like, do not try to read from a buffer that isn't in the group chat 🫶

mode is initially GL_FRONT in single-buffered configurations, and GL_BACK in double-buffered configurations. That's the default vibe check.

💀 ERRORS 💀

• GL_INVALID_ENUM is generated if mode is not one of the twelve (or more) accepted values. Not an accepted value? bestie, no 💀
• GL_INVALID_OPERATION is generated if mode specifies a buffer that does not exist.
• GL_INVALID_OPERATION is generated if glReadBuffer is executed between the execution of glBegin and the corresponding execution of glEnd. Do not do this mid-glBegin/glEnd, fr fr 😭

🔥 ASSOCIATED GETS 🔥

glGet with argument GL_READ_BUFFER — that's the query bestie, iykyk.

🌟 SEE ALSO 🌟

• glCopyPixels(3G)
• glCopyTexImage1D(3G)
• glCopyTexImage2D(3G)
• glCopyTexSubImage1D(3G)
• glCopyTexSubImage2D(3G)
• glCopyTexSubImage3D(3G)
• glDrawBuffer(3G)
• glReadPixels(3G)

cute sign-off time: the footer on this one is just GLREADBUFFER(3G) — no separate source/version/date line was provided — so that's the whole footer vibe. bye bestie 🫶💅