-improved WASM compilation scripts

-added external bindbc.sdl import for WASM
-working on demos (WIP, working simple demo with ECS and SDL2)
-small change in ecs.std

demos/simple/source/app.d

@@ -0,0 +1,216 @@
+module source.app;
+
+import ecs.std;
+import ecs.core;
+import ecs.manager;
+import ecs.attributes;
+import ecs.entity;
+
+import bindbc.sdl;
+
+import utils.utils;
+import utils.texture;
+
+import ecs_utils.math.vector;
+
+version (WebAssembly)
+{
+    extern (C) void _start()
+    {
+    }
+}
+
+SDL_Renderer *renderer;
+SDL_Window* window;
+Texture texture;
+EntityManager* manager;
+
+struct CLocation
+{
+    mixin ECS.Component;
+
+    alias location this;
+
+    vec2 location;
+}
+
+struct CTexture
+{
+    mixin ECS.Component;
+
+    Texture tex;
+}
+
+struct DrawSystem
+{
+    mixin ECS.System;
+
+    struct EntitiesData
+    {
+        uint length;
+        @readonly CTexture[] textures;
+        @readonly CLocation[] locations;
+    }
+
+    void onUpdate(EntitiesData data)
+    {
+        foreach(i; 0..data.length)
+        {
+            draw(renderer, data.textures[i].tex, data.locations[i], vec2(32,32), vec4(0,0,1,1));
+        }
+    }
+}
+
+struct MoveSystem
+{
+    mixin ECS.System;
+
+    struct EntitiesData
+    {
+        uint length;
+        CLocation[] locations;
+    }
+
+    void onUpdate(EntitiesData data)
+    {
+        foreach(i; 0..data.length)
+        {
+            data.locations[i].location.y = data.locations[i].location.y + 1; 
+            if(data.locations[i].location.y > 400)data.locations[i].location.y = 0;
+        }
+    }
+}
+
+extern (C) int main(int argc, char** argv)
+{
+    fps = 0;
+    time = 0;
+
+    if (SDL_Init(SDL_INIT_VIDEO) < 0)
+    {
+        printf("SDL could not initialize! SDL_Error: %s", SDL_GetError());
+        return -1;
+    }
+
+    SDL_version sdl_version;
+    SDL_GetVersion(&sdl_version);
+    printf("SDL version: %u.%u.%u\n",cast(uint)sdl_version.major,cast(uint)sdl_version.minor,cast(uint)sdl_version.patch);
+    
+    SDL_Window* window = SDL_CreateWindow("Simple", SDL_WINDOWPOS_CENTERED,
+                SDL_WINDOWPOS_CENTERED, 600, 400, SDL_WINDOW_SHOWN);
+    //SDL_CreateWindowAndRenderer(600, 400, SDL_RENDERER_ACCELERATED, &window, &renderer);
+    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
+    SDL_SetRenderDrawColor(renderer, 1, 255, 255, 255);
+
+    texture.create();
+    texture.load(renderer, "assets/textures/buckler.png");
+
+    EntityManager.initialize(8);
+    manager = EntityManager.instance;
+
+    manager.beginRegister();
+
+    manager.registerComponent!CLocation;
+    manager.registerComponent!CTexture;
+
+    manager.registerSystem!MoveSystem(64);
+    manager.registerSystem!DrawSystem(64);
+
+    manager.endRegister();
+
+    ushort[2] components = [CLocation.component_id, CTexture.component_id];
+    EntityTemplate* tmpl = manager.allocateTemplate(components);
+    CTexture* tex_comp = tmpl.getComponent!CTexture;
+    tex_comp.tex = texture;
+    CLocation* loc_comp = tmpl.getComponent!CLocation;
+   // loc_comp.location = vec2(64,64);
+
+    foreach(i; 0..10)
+        foreach(j; 0..10)
+        {
+            loc_comp.location = vec2(i*32+64,j*32+64);
+            manager.addEntity(tmpl);
+        }
+    
+
+    manager.freeTemplate(tmpl);
+
+    /*image = IMG_Load("assets/owl.png");
+    tex = SDL_CreateTextureFromSurface(renderer, image);*/
+
+    version(WebAssembly)
+    {
+        emscripten_set_main_loop_arg(&loop, null, -1, 1);
+    }
+    
+    bool arg = true;
+    while(arg == true)
+    {
+        loop(&arg);
+    }
+
+    if (window !is null) {
+		SDL_DestroyWindow(window);
+	}
+
+    end();
+
+    return 0;
+}
+
+long time;
+uint fps;
+
+extern(C) void loop(void *arg = null)
+{
+    static float fps_time = 0;
+    float delta_time = cast(float)(Time.getUSecTime() - time);
+    if(delta_time > 1000_000)delta_time = 1000;
+    time = Time.getUSecTime();
+
+    if(fps_time < 0)fps_time = 0;
+
+    fps++;
+    fps_time += delta_time;
+    if(fps_time > 1000_000)
+    {
+        
+        printf("FPS: %u\n",fps);
+        fps = 0;
+        fps_time -= 1000_000;
+    }
+
+    SDL_Event event;
+    while (SDL_PollEvent(&event)) 
+    {
+        if (event.type == SDL_QUIT) {
+            version(WebAssembly)emscripten_cancel_main_loop();
+            *cast(bool*)arg = false;
+            //return false;
+        }
+
+        if (event.type == SDL_KEYDOWN) {
+            version(WebAssembly)emscripten_cancel_main_loop();
+            *cast(bool*)arg = false;
+            //return false;
+        }
+    }
+
+    SDL_RenderClear(renderer);
+
+    manager.begin();
+    manager.update();
+    manager.end();
+
+    draw(renderer,texture,vec2(32,32),vec2(32,32),vec4(0,0,1,1));
+    //SDL_RenderCopy(ctx->renderer, ctx->owl_tex, NULL, &ctx->dest);
+    SDL_RenderPresent(renderer);
+
+    //return true;
+}
+
+void end()
+{
+    EntityManager.destroy();
+    SDL_Quit();
+}