Implement basic map drawing from tileset

CMakeLists.txt

@@ -36,6 +36,7 @@ add_custom_target(lint
 
 find_package(LibXml2 REQUIRED)
 find_package(SDL2 REQUIRED CONFIG REQUIRED COMPONENTS SDL2 SDL2main)
+find_package(SDL2_image REQUIRED)
 
 add_subdirectory(engine)
 add_subdirectory(app)

app/CMakeLists.txt

@@ -4,5 +4,9 @@ add_executable(game
 set_default_target_options(game)
 target_include_directories(game PUBLIC include)
 
-target_link_libraries(game
+target_link_libraries(game PRIVATE
-  PRIVATE LibXml2::LibXml2 SDL2::SDL2 SDL2::SDL2main)
+  LibXml2::LibXml2
+  SDL2::SDL2
+  SDL2::SDL2main
+  SDL2_image::SDL2_image
+)

app/main.c

@@ -4,14 +4,15 @@
  */
 
 #include <SDL2/SDL.h>
+#include <SDL2/SDL_image.h>
 #include <assert.h>
 #include <ctype.h>
 #include <libxml/parser.h>
 #include <string.h>
 
 #define TILESIZE 32
-#define WINWIDTH 30
+#define VIEWWIDTH 30
-#define WINHEIGHT 20
+#define VIEWHEIGHT 20
 
 #define MAX_PATH_LEN 128
 
@@ -21,9 +22,13 @@
 #define MAPSHIFTX 48
 #define MAPSHIFTY 48
 
+#define TSASSET "/tileset.png"
+#define TSCOLS 56
+
 static SDL_Window *window;
 static SDL_Renderer *renderer;
 static unsigned map[MAPWIDTH][MAPHEIGHT];
+static SDL_Texture *tstex;
 
 int main(int argc, char *argv[])
 {
@@ -39,7 +44,7 @@ int main(int argc, char *argv[])
 	assert(0 == err);
 	window = SDL_CreateWindow(
 	    "2D Game", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
-	    TILESIZE * WINWIDTH, TILESIZE * WINHEIGHT, 0);
+	    TILESIZE * VIEWWIDTH, TILESIZE * VIEWHEIGHT, 0);
 	assert(NULL != window);
 	renderer = SDL_CreateRenderer(window, -1, 0);
 	assert(NULL != renderer);
@@ -115,8 +120,40 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	SDL_Event event;
+	// Load tileset
+	assert(strlen(argv[1]) + strlen(TSASSET) < MAX_PATH_LEN);
+	strcpy(path, argv[1]);
+	strcat(path, TSASSET);
+	tstex = IMG_LoadTexture(renderer, path);
+	assert(NULL != tstex);
+
+	// Render map -- no motion yet so just needs to be done once
+	int offx = 0, offy = 0;
 	SDL_RenderClear(renderer);
+	for (int y = 0; y < VIEWHEIGHT; ++y) {
+		for (int x = 0; x < VIEWWIDTH; ++x) {
+			const unsigned tileid
+			    = map[x + offx + MAPSHIFTX][y + offy + MAPSHIFTY];
+			if (0 == tileid)
+				continue;
+			const SDL_Rect src = {
+				.x = TILESIZE * ((tileid - 1) % TSCOLS),
+				.y = TILESIZE * ((tileid - 1) / TSCOLS),
+				.w = TILESIZE,
+				.h = TILESIZE,
+			};
+			const SDL_Rect dest = {
+				.x = TILESIZE * x,
+				.y = TILESIZE * y,
+				.w = TILESIZE,
+				.h = TILESIZE,
+			};
+			SDL_RenderCopy(renderer, tstex, &src, &dest);
+		}
+	}
+	SDL_RenderPresent(renderer);
+
+	SDL_Event event;
 	while (1) {
 		SDL_PollEvent(&event);
 		switch (event.type) {