1 files changed, 100 insertions, 0 deletions
diff --git a/platform.c b/platform.c
new file mode 100644
index 0000000..7ba6d53
--- /dev/null
+++ b/platform.c
@@ -0,0 +1,100 @@
+#include <SDL2/SDL.h>
+
+#define WINDOW_W 1280
+#define WINDOW_H 720
+
+SDL_Renderer *context = 0;
+SDL_Texture *background = 0;
+SDL_Texture *foreground = 0;
+SDL_Texture *terrain = 0;
+SDL_Texture *mask_texture = 0;
+
+double GetCurrentTimestamp() {
+	return (double) SDL_GetTicks64() / 1000.0;
+}
+
+SDL_Texture *createTiledTexture(SDL_Renderer *context, const char *filename, int width, int height) {
+	SDL_Surface *texture_surface = SDL_LoadBMP(filename);
+	SDL_Texture *texture_tile = SDL_CreateTextureFromSurface(context, texture_surface);
+	int tile_w = texture_surface->w;
+	int tile_h = texture_surface->h;
+	SDL_FreeSurface(texture_surface);
+
+	SDL_Texture *texture = SDL_CreateTexture(context,
+			SDL_PIXELFORMAT_RGBA8888,
+			SDL_TEXTUREACCESS_TARGET,
+			width, height);
+	SDL_SetRenderTarget(context, texture);
+	for (int y = 0; y < height; y += tile_h) {
+		for (int x = 0; x < width; x += tile_w) {
+			SDL_Rect tile_rect = { x, y, tile_w, tile_h };
+			SDL_RenderCopy(context, texture_tile, 0, &tile_rect);
+		}
+	}
+	SDL_DestroyTexture(texture_tile);
+	SDL_SetRenderTarget(context, 0);
+	return texture;
+}
+
+void PlatformMain(void (*GameMain)(void)) {
+	SDL_Init(SDL_INIT_VIDEO);
+
+	SDL_Window *window = SDL_CreateWindow("Cannons",
+			SDL_WINDOWPOS_UNDEFINED,
+			SDL_WINDOWPOS_UNDEFINED,
+			WINDOW_W,
+			WINDOW_H,
+			0);
+
+	context = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
+
+	background = createTiledTexture(context, "background.bmp", WINDOW_W, WINDOW_H);
+
+	foreground = createTiledTexture(context, "foreground.bmp", WINDOW_W, WINDOW_H);
+	SDL_SetTextureBlendMode(foreground, SDL_BLENDMODE_MOD);
+
+	terrain = SDL_CreateTexture(context,
+			SDL_PIXELFORMAT_RGBA8888,
+			SDL_TEXTUREACCESS_TARGET,
+			WINDOW_W, WINDOW_H);
+	SDL_SetTextureBlendMode(terrain, SDL_BLENDMODE_BLEND);
+
+	mask_texture = SDL_CreateTexture(context,
+			SDL_PIXELFORMAT_RGBA8888,
+			SDL_TEXTUREACCESS_STREAMING,
+			WINDOW_W, WINDOW_H);
+
+	GameMain();
+
+	SDL_DestroyRenderer(context);
+	SDL_DestroyWindow(window);
+	SDL_Quit();
+}
+
+void RenderScene(float *mask, int player_x, int player_y) {
+	void *pixels;
+	int pitch;
+	SDL_LockTexture(mask_texture, 0, &pixels, &pitch);
+	Uint32 *p = (Uint32 *) pixels;
+	for (int j = 0; j < WINDOW_H; j++) {
+		for (int i = 0; i < WINDOW_W; i++) {
+			p[i + j * WINDOW_W] = mask[i + (WINDOW_H - j) * WINDOW_W] ? 0xffffffff : 0x00000000;
+		}
+	}
+	SDL_UnlockTexture(mask_texture);
+
+	SDL_SetRenderDrawColor(context, 40, 40, 40, 255);
+	SDL_RenderClear(context);
+	SDL_RenderCopy(context, background, 0, 0);
+	SDL_SetRenderTarget(context, terrain);
+	SDL_SetRenderDrawColor(context, 0, 0, 0, 0);
+	SDL_RenderClear(context);
+	SDL_RenderCopy(context, mask_texture, 0, 0);
+	SDL_RenderCopy(context, foreground, 0, 0);
+	SDL_SetRenderTarget(context, 0);
+	SDL_RenderCopy(context, terrain, 0, 0);
+	SDL_SetRenderDrawColor(context, 255, 0, 0, 255);
+	SDL_Rect player_rect = {player_x - 5, WINDOW_H - player_y - 10, 10, 10 };
+	SDL_RenderFillRect(context, &player_rect);
+	SDL_RenderPresent(context);
+}