Added scaling and ready to start with sdl_image

src/main.zig

@@ -1,5 +1,6 @@
 const c = @cImport({
     @cInclude("SDL2/SDL.h");
+    @cInclude("SDL2/SDL_image.h");
 });
 
 const std = @import("std");
@@ -10,7 +11,6 @@ const log = c.SDL_Log;
 
 var window: *c.struct_SDL_Window = undefined;
 var screen_surface: *c.struct_SDL_Surface = undefined;
-var zig_image: *c.struct_SDL_Surface = undefined;
 const Offset = struct {
     x: i32,
     y: i32,
@@ -21,8 +21,10 @@ pub fn main() !void {
     try init();
     defer close();
 
-    try loadMedia();
-    var src_rect: c.struct_SDL_Rect = c.SDL_Rect{ .x = 10, .y = 10, .w = 400, .h = 140 };
+    const zig_image = try loadSurface("assets/stretch.bmp");
+    defer c.SDL_FreeSurface(zig_image);
+
+    var src_rect: c.struct_SDL_Rect = c.SDL_Rect{ .x = 0, .y = 0, .w = SCREEN_WIDTH / 2, .h = SCREEN_HEIGHT / 2 };
 
     var quit = false;
     while (!quit) {
@@ -41,10 +43,10 @@ pub fn main() !void {
                             img_pos.y = img_pos.y + 5;
                         },
                         c.SDLK_LEFT => {
-                            img_pos.x = img_pos.x + 5;
+                            img_pos.x = img_pos.x - 5;
                         },
                         c.SDLK_RIGHT => {
-                            img_pos.x = img_pos.x - 5;
+                            img_pos.x = img_pos.x + 5;
                         },
                         else => {},
                     }
@@ -54,8 +56,8 @@ pub fn main() !void {
             }
         }
         _ = c.SDL_FillRect(screen_surface, null, c.SDL_MapRGB(screen_surface.format, 0xff, 0xff, 0xff));
-        var dest_rect = c.SDL_Rect{ .x = src_rect.x + img_pos.x, .y = src_rect.y + img_pos.y, .w = src_rect.w, .h = src_rect.h };
-        _ = c.SDL_BlitSurface(zig_image, &src_rect, screen_surface, &dest_rect);
+        var dest_rect = c.SDL_Rect{ .x = src_rect.x + img_pos.x, .y = src_rect.y + img_pos.y, .w = SCREEN_WIDTH, .h = SCREEN_HEIGHT };
+        _ = c.SDL_BlitScaled(zig_image, &src_rect, screen_surface, &dest_rect);
 
         _ = c.SDL_UpdateWindowSurface(window);
         c.SDL_Delay(17);
@@ -77,22 +79,33 @@ fn init() !void {
     }
     window = opt_window.?;
 
-    // get surface and fill with white
     screen_surface = c.SDL_GetWindowSurface(window);
-}
 
-fn loadMedia() !void {
-    const image: [*c]c.struct_SDL_Surface = c.SDL_LoadBMP("src/zig.bmp");
-    if (image == null) {
-        log("Unable to load media: %s\n", c.SDL_GetError());
-        return error.SDLLoadError;
-    } else {
-        zig_image = image;
+    const img_flags = c.IMG_INIT_PNG;
+    if (c.IMG_Init(img_flags) != img_flags) {
+        log("Unable to initialize SDL Image: %s\n", c.IMG_GetError());
+        return error.SDLInitializationFailed;
     }
 }
 
+fn loadSurface(path: [*c]const u8) !*c.struct_SDL_Surface {
+    // TODO check file exists
+    const loaded_surface: [*c]c.struct_SDL_Surface = c.SDL_LoadBMP(path);
+    if (loaded_surface == null) {
+        log("Unable to load media at path %s: %s\n", path, c.SDL_GetError());
+        return error.SDLLoadError;
+    }
+    defer c.SDL_FreeSurface(loaded_surface);
+    // Converting 24bit bmp to 32bit to match display
+    const optimized_surface = c.SDL_ConvertSurface(loaded_surface, screen_surface.format, 0);
+    if (optimized_surface == null) {
+        log("Unable to optimize media at path %s: %s\n", path, c.SDL_GetError());
+        return error.SDLLoadError;
+    }
+    return optimized_surface;
+}
+
 fn close() void {
-    c.SDL_FreeSurface(zig_image);
     c.SDL_DestroyWindow(window);
     c.SDL_Quit();
 }