use stb_image.h instead of SDL2_image

CMakeLists.txt

@@ -4,7 +4,6 @@ project(townengine LANGUAGES C)
 
 # SDL dependencies
 find_package(SDL2 REQUIRED GLOBAL)
-find_package(SDL2_image REQUIRED GLOBAL)
 
 # CMake actually has no default configuration and it's toolchain file dependent, set debug if not specified
 if(NOT CMAKE_BUILD_TYPE)
@@ -164,6 +163,7 @@ function(give_options target)
                 -Wconversion -Wno-sign-conversion
                 -Werror=vla
                 -Wno-missing-field-initializers
+                -Wunused-result
                 $<$<STREQUAL:${CMAKE_C_COMPILER_ID},Gnu>:-Wcast-align=strict>)
 
         target_compile_options(${target} PRIVATE
@@ -194,7 +194,6 @@ endfunction()
 function(link_deps target)
         target_link_libraries(${target} PUBLIC
                                         SDL2::SDL2
-                                        SDL2_image::SDL2_image
                                         physfs-static
                                         xms)
 endfunction()

townengine/textures/textures.c

@@ -4,12 +4,14 @@
 #include "townengine/context.h"
 
 #include <SDL2/SDL.h>
-#include <SDL2/SDL_image.h>
 #include <physfs.h>
 #include <physfsrwops.h>
 #include <stb_ds.h>
 #include <stb_rect_pack.h>
 
+#define STB_IMAGE_IMPLEMENTATION
+#include <stb_image.h>
+
 #include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -18,18 +20,62 @@
 static SDL_Surface *image_to_surface(const char *path) {
     SDL_RWops *handle = PHYSFSRWOPS_openRead(path);
     if (handle == NULL)
-        goto fail;
-    
-    SDL_Surface *result = IMG_Load_RW(handle, true);
-    if (result == NULL)
-        goto fail;
+        goto ERR_CANNOT_OPEN_FILE;
 
-    SDL_SetSurfaceBlendMode(result, SDL_BLENDMODE_NONE);
-    SDL_SetSurfaceRLE(result, true);
+    /* TODO: try using callbacks so that less memory is used */
+    Sint64 file_size = handle->size(handle);
+    SDL_assert_always(file_size != -1);
+    void *file_mem = malloc(file_size);
+    size_t read = handle->read(handle, file_mem, 1, file_size);
+    SDL_assert_always(read == (size_t)file_size);
+    SDL_FreeRW(handle);
 
-    return result;
+    if (!file_mem)
+        goto ERR_CANNOT_ALLOCATE_MEM;
 
-fail:
+    int width, height, channels;
+    void *image_mem = stbi_load_from_memory(file_mem, (int)file_size, &width, &height, &channels, 4);
+    if (!image_mem)
+        goto ERR_CANNOT_READ_IMAGE;
+
+    free(file_mem);
+
+    Uint32 rmask, gmask, bmask, amask;
+
+    #if SDL_BYTEORDER == SDL_BIG_ENDIAN
+        rmask = 0xff000000;
+        gmask = 0x00ff0000;
+        bmask = 0x0000ff00;
+        amask = 0x000000ff;
+    #else
+        rmask = 0x000000ff;
+        gmask = 0x0000ff00;
+        bmask = 0x00ff0000;
+        amask = 0xff000000;
+    #endif
+
+    SDL_Surface* surface = SDL_CreateRGBSurfaceFrom(image_mem, width, height,
+                                                    channels * 8,
+                                                    width * channels,
+                                                    rmask, gmask, bmask, amask);
+    if (surface == NULL)
+        goto ERR_CANNOT_CREATE_SURFACE;
+
+    SDL_SetSurfaceBlendMode(surface, SDL_BLENDMODE_NONE);
+    SDL_SetSurfaceRLE(surface, true);
+
+    return surface;
+
+ERR_CANNOT_CREATE_SURFACE:
+    stbi_image_free(image_mem);
+
+ERR_CANNOT_READ_IMAGE:
+    free(file_mem);
+
+ERR_CANNOT_ALLOCATE_MEM:
+    SDL_FreeRW(handle);
+
+ERR_CANNOT_OPEN_FILE:
     CRY(path, "Failed to load image. Aborting...");
     die_abruptly();
 }
@@ -276,7 +322,9 @@ void textures_dump_atlases(struct texture_cache *cache) {
             return;
         }
 
-        IMG_SavePNG_RW(cache->atlas_surfaces[i], handle, true);
+        /* TODO: */
+        // IMG_SavePNG_RW(cache->atlas_surfaces[i], handle, true);
+        CRY("Unimplemented", "textures_dump_atlases dumping is not there, sorry");
         log_info("Dumped atlas %s", buf);
     }
 }

townengine/twn_loop.c

@@ -283,12 +283,6 @@ static bool initialize(void) {
 
     }
 
-    /* images */
-    if (IMG_Init(IMG_INIT_PNG) == 0) {
-        CRY_SDL("SDL_image initialization failed.");
-        goto fail;
-    }
-
     /* filesystem time */
     /* TODO: ANDROID: see the warning in physicsfs PHYSFS_init docs/header */
     if (!PHYSFS_init(ctx.argv[0]) ||
@@ -375,7 +369,6 @@ static void clean_up(void) {
     textures_cache_deinit(&ctx.texture_cache);
 
     PHYSFS_deinit();
-    IMG_Quit();
     SDL_Quit();
 }