SDL_SetSurfaceAlphaMod(3)

📦
version 3.4.18 · 9 versions
, in fedora 43, fedora 44

✨ SDL_SetSurfaceAlphaMod(3) ✨

okay bestie, welcome to the SDL3 FUNCTIONS section of the SDL_SetSurfaceAlphaMod manual page 💖 this one is short, sweet, and honestly iconic for what it does.

🌸 NAME 🌸

SDL_SetSurfaceAlphaMod — set an extra alpha value that gets used in blit operations 🎀

🦋 SYNOPSIS 🦋

#include <SDL3/SDL_surface.h>

bool SDL_SetSurfaceAlphaMod(SDL_Surface *surface, Uint8 alpha);

💅 DESCRIPTION 💅

so here's the tea: when this surface gets blitted, the blit operation takes the source alpha value and modulates it by this alpha value, using this exact formula:

srcA = srcA * (alpha / 255)

that's it. that's the whole vibe. no cap 🌈

🍓 FUNCTION PARAMETERS 🍓

  • surface — the SDL_Surface structure you wanna update 💜
  • alpha — the alpha value that gets multiplied into blit operations ✨

💀 RETURN VALUE 💀

Returns true on success or false on failure 🫶 and if it fails, bestie, call SDL_GetError() for more info. go get that lore.

🧚 THREAD SAFETY 🧚

good news: you can call this function on different threads — as long as you're using different surfaces. main character multitasking energy 👑

⭐ AVAILABILITY ⭐

this function has been available since SDL 3.2.0. ancient by now, but still slaying.

👑 SEE ALSO 👑

Simple Directmedia Layer · SDL 3.4.18 · SDL_SetSurfaceAlphaMod(3) — okay that's the whole page, mwah 💋 go modulate some alpha, you've got this, ily, bye 🦋💖

📦 where this page comes from