Removed stb_image.h from SDL

This adds quite a bit of code size to SDL for a niche use-case. This is easily handled in the application instead.

src/SDL_internal.h

@@ -191,11 +191,6 @@
 #define SDL_VIDEO_RENDER_SW 1
 #endif
 
-/* STB image conversion */
-#if !defined(SDL_HAVE_STB) && !defined(SDL_LEAN_AND_MEAN)
-#define SDL_HAVE_STB 1
-#endif
-
 /* YUV formats
    - handling of YUV surfaces
    - blitting and conversion functions */

src/render/SDL_render.c

@@ -1282,14 +1282,7 @@ static SDL_PixelFormat GetClosestSupportedFormat(SDL_Renderer *renderer, SDL_Pix
 {
     int i;
 
-    if (format == SDL_PIXELFORMAT_MJPG) {
-        // We'll decode to SDL_PIXELFORMAT_RGBA32
-        for (i = 0; i < renderer->num_texture_formats; ++i) {
-            if (renderer->texture_formats[i] == SDL_PIXELFORMAT_RGBA32) {
-                return renderer->texture_formats[i];
-            }
-        }
-    } else if (SDL_ISPIXELFORMAT_FOURCC(format)) {
+    if (SDL_ISPIXELFORMAT_FOURCC(format)) {
         // Look for an exact match
         for (i = 0; i < renderer->num_texture_formats; ++i) {
             if (renderer->texture_formats[i] == format) {
@@ -1451,9 +1444,7 @@ SDL_Texture *SDL_CreateTextureWithProperties(SDL_Renderer *renderer, SDL_Propert
         texture->next = texture->native;
         renderer->textures = texture;
 
-        if (texture->format == SDL_PIXELFORMAT_MJPG) {
-            // We have a custom decode + upload path for this
-        } else if (SDL_ISPIXELFORMAT_FOURCC(texture->format)) {
+        if (SDL_ISPIXELFORMAT_FOURCC(texture->format)) {
 #ifdef SDL_HAVE_YUV
             texture->yuv = SDL_SW_CreateYUVTexture(texture->format, texture->colorspace, w, h);
 #else

src/video/SDL_stb.c

@@ -1,92 +0,0 @@
-/*
-  Simple DirectMedia Layer
-  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
-
-  This software is provided 'as-is', without any express or implied
-  warranty.  In no event will the authors be held liable for any damages
-  arising from the use of this software.
-
-  Permission is granted to anyone to use this software for any purpose,
-  including commercial applications, and to alter it and redistribute it
-  freely, subject to the following restrictions:
-
-  1. The origin of this software must not be misrepresented; you must not
-     claim that you wrote the original software. If you use this software
-     in a product, an acknowledgment in the product documentation would be
-     appreciated but is not required.
-  2. Altered source versions must be plainly marked as such, and must not be
-     misrepresented as being the original software.
-  3. This notice may not be removed or altered from any source distribution.
-*/
-#include "SDL_internal.h"
-
-#include "SDL_stb_c.h"
-
-
-// We currently only support JPEG, but we could add other image formats if we wanted
-#ifdef SDL_HAVE_STB
-#define malloc SDL_malloc
-#define realloc SDL_realloc
-#define free SDL_free
-#undef memcpy
-#define memcpy SDL_memcpy
-#undef memset
-#define memset SDL_memset
-#undef strcmp
-#define strcmp SDL_strcmp
-#undef strncmp
-#define strncmp SDL_strncmp
-#define strtol SDL_strtol
-
-#define abs SDL_abs
-#define pow SDL_pow
-#define ldexp SDL_scalbn
-
-#define STB_INTERNAL_SDL
-#define STB_IMAGE_STATIC
-#define STBI_FAILURE_USERMSG
-#if defined(__ARM_NEON)
-#define STBI_NEON
-#endif
-#define STBI_ONLY_JPEG
-#define STBI_NO_GIF
-#define STBI_NO_PNG
-#define STBI_NO_HDR
-#define STBI_NO_LINEAR
-#define STBI_NO_ZLIB
-#define STBI_NO_STDIO
-#define STBI_ASSERT SDL_assert
-#define STB_IMAGE_IMPLEMENTATION
-#include "stb_image.h"
-#endif
-
-bool SDL_ConvertPixels_STB(int width, int height,
-                           SDL_PixelFormat src_format, SDL_Colorspace src_colorspace, SDL_PropertiesID src_properties, const void *src, int src_pitch,
-                           SDL_PixelFormat dst_format, SDL_Colorspace dst_colorspace, SDL_PropertiesID dst_properties, void *dst, int dst_pitch)
-{
-#ifdef SDL_HAVE_STB
-    if (src_colorspace != dst_colorspace) {
-        return SDL_SetError("SDL_ConvertPixels_STB: colorspace conversion not supported");
-    }
-
-    if (src_format == dst_format) {
-        if (src == dst) {
-            // Nothing to do
-            return true;
-        }
-    }
-
-    int w = 0, h = 0, format = 0;
-    stbi_uc *pixels = stbi_load_from_memory((const stbi_uc *)src, src_pitch, &w, &h, &format, 4);
-    if (!pixels) {
-        return SDL_SetError("Couldn't decode image: %s", stbi_failure_reason());
-    }
-
-    bool result = SDL_ConvertPixelsAndColorspace(w, h, SDL_PIXELFORMAT_RGBA32, src_colorspace, src_properties, pixels, width * 4, dst_format, dst_colorspace, dst_properties, dst, dst_pitch);
-    stbi_image_free(pixels);
-
-    return result;
-#else
-    return SDL_SetError("SDL not built with STB image support");
-#endif
-}

src/video/SDL_stb_c.h

@@ -1,31 +0,0 @@
-/*
-  Simple DirectMedia Layer
-  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
-
-  This software is provided 'as-is', without any express or implied
-  warranty.  In no event will the authors be held liable for any damages
-  arising from the use of this software.
-
-  Permission is granted to anyone to use this software for any purpose,
-  including commercial applications, and to alter it and redistribute it
-  freely, subject to the following restrictions:
-
-  1. The origin of this software must not be misrepresented; you must not
-     claim that you wrote the original software. If you use this software
-     in a product, an acknowledgment in the product documentation would be
-     appreciated but is not required.
-  2. Altered source versions must be plainly marked as such, and must not be
-     misrepresented as being the original software.
-  3. This notice may not be removed or altered from any source distribution.
-*/
-
-#ifndef SDL_stb_c_h_
-#define SDL_stb_c_h_
-
-#include "SDL_internal.h"
-
-// Image conversion functions
-
-extern bool SDL_ConvertPixels_STB(int width, int height, SDL_PixelFormat src_format, SDL_Colorspace src_colorspace, SDL_PropertiesID src_properties, const void *src, int src_pitch, SDL_PixelFormat dst_format, SDL_Colorspace dst_colorspace, SDL_PropertiesID dst_properties, void *dst, int dst_pitch);
-
-#endif // SDL_stb_c_h_

src/video/SDL_surface.c

@@ -24,7 +24,6 @@
 #include "SDL_video_c.h"
 #include "SDL_RLEaccel_c.h"
 #include "SDL_pixels_c.h"
-#include "SDL_stb_c.h"
 #include "SDL_yuv_c.h"
 #include "../render/SDL_sysrender.h"
 
@@ -2278,10 +2277,6 @@ bool SDL_ConvertPixelsAndColorspace(int width, int height,
         dst_colorspace = SDL_GetDefaultColorspaceForFormat(dst_format);
     }
 
-    if (src_format == SDL_PIXELFORMAT_MJPG) {
-        return SDL_ConvertPixels_STB(width, height, src_format, src_colorspace, src_properties, src, src_pitch, dst_format, dst_colorspace, dst_properties, dst, dst_pitch);
-    }
-
 #ifdef SDL_HAVE_YUV
     if (SDL_ISPIXELFORMAT_FOURCC(src_format) && SDL_ISPIXELFORMAT_FOURCC(dst_format)) {
         return SDL_ConvertPixels_YUV_to_YUV(width, height, src_format, src_colorspace, src_properties, src, src_pitch, dst_format, dst_colorspace, dst_properties, dst, dst_pitch);