gamelib/src/Image.cake

;; Image
;; Interface for loading images of various formats
;; Currently, stb_image.h does all the heavy lifting
(export-and-evaluate
 (comptime-cond
  ('STBImageDefinedInRaylib
   (add-c-search-directory-module "Dependencies"))
 (true
  (add-c-search-directory-module "Dependencies/stb"))))
(import "STB.cake") ;; Download STB if necessary

;; If another dependency includes stb_image (it's quite popular), then we don't need to add the
;; implementations here (and cause multiple definitions)
(comptime-cond
 ('STBImageDefinedInRaylib)
 (true
  (c-preprocessor-define STB_IMAGE_IMPLEMENTATION)))
(c-preprocessor-define STBI_FAILURE_USERMSG)
;; This is an annoying hack: Raylib uses a different version of stb, so if we import Raylib.cake
;; and Image.cake (must be in that order!), we need to use Raylib's version, because I don't want
;; to modify raylib.
(comptime-cond
 ('STBImageDefinedInRaylib
  ;; I don't want to expose raylib/src/external because it breaks other modules in GameLib
  (c-import &with-decls "raylib/src/external/stb_image.h"
            &with-defs "raylib/src/external/stb_image.h"))
 (true
  (c-import &with-decls "stb_image.h"
            &with-defs "stb_image.h")))

(comptime-cond
 ('auto-test
  (defun-nodecl test--stb-image (&return int)
    (var image-to-load (* (const char)) "assets/town.jpg")
    (var width int 0)
    (var height int 0)
    (var num-pixel-components int 0)
    (var num-desired-channels int 3)
    (var pixel-data (* (unsigned char))
      (stbi_load image-to-load (addr width) (addr height) (addr num-pixel-components)
                 num-desired-channels))
    (unless pixel-data
      (fprintf stderr "error: failed to load %s with message: %s\n" image-to-load
               (stbi_failure_reason))
      (return 1))

    (fprintf stderr "size of %s: %dx%d\n" image-to-load width height)
    (fprintf stderr "num components in %s: %d\n" image-to-load num-pixel-components)
    (fprintf stderr "first three pixels:\n")
    (each-in-range 3 i
      (var rgb-components ([] 3 (unsigned char)) (array 0))
      (memcpy rgb-components (addr (at (* i 3) pixel-data))
              (sizeof rgb-components))
      (fprintf stderr "[%d] %d %d %d\n"
               i
               (at 0 rgb-components)
               (at 1 rgb-components)
               (at 2 rgb-components)))

    (stbi_image_free pixel-data)
    (return 0))))