direction_for_rotation(9)

💅 NAME 💅

okay so bestie, welcome to the Kernel API Manual — the main character here is direction_for_rotation, and it is literally about getting the correct reading direction for a given rotation. 💖

✨ SYNOPSIS ✨

enum pixel_read_direction direction_for_rotation (unsigned int rotation
);

🧚 ARGUMENTS 🧚

• rotation — the rotation to analyze, bestie. It corresponds to the field frame_info.rotation. 💫

🌸 DESCRIPTION 🌸

This function uses the rotation setting of a source plane to compute the reading direction in that plane which corresponds to a "left to right writing" in the CRTC. periodt. 💅

For example, if the buffer is reflected on the X axis, the pixel must be read from right to left to be written from left to right on the CRTC. no cap, that is the whole vibe. ✨

🦋 SEE ALSO 🦋

• Kernel file ./drivers/gpu/drm/vkms/vkms_composer.c
• pre_mul_alpha_blend(9)
• clamp_line_coordinates(9)
• blend_line(9)
• blend(9)
• vkms_composer_worker(9)

mwah 💋 this cutie is from the ./drivers/gpu/drm/vkms source/version, dated October 2026, and the page is direction_for_rotation(9) — bye bestie, go slay some rotation logic 🫶