2 files changed, 182 insertions, 0 deletions

diff --git a/demos/checkerboard/CMakeLists.txt b/demos/checkerboard/CMakeLists.txt
new file mode 100644
index 0000000..d1691c6
--- /dev/null
+++ b/demos/checkerboard/CMakeLists.txt
@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.0)
+
+project(checkerboard)
+
+set(CMAKE_C_STANDARD 17)
+set(CMAKE_C_STANDARD_REQUIRED On)
+set(CMAKE_C_EXTENSIONS Off)
+
+add_executable(checkerboard
+  checkerboard.c)
+
+target_link_libraries(checkerboard PRIVATE
+  gfx-app
+  isogfx-backend)
+
+target_compile_options(checkerboard PRIVATE -Wall -Wextra -Wpedantic)
diff --git a/demos/checkerboard/checkerboard.c b/demos/checkerboard/checkerboard.c
new file mode 100644
index 0000000..dbc817c
--- /dev/null
+++ b/demos/checkerboard/checkerboard.c
@@ -0,0 +1,166 @@
+#include <isogfx/backend.h>
+#include <isogfx/isogfx.h>
+
+#include <gfx/app.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+static const int WINDOW_WIDTH  = 1408;
+static const int WINDOW_HEIGHT = 960;
+static const int MAX_FPS       = 60;
+
+// Virtual screen dimensions.
+static const int SCREEN_WIDTH  = 704;
+static const int SCREEN_HEIGHT = 480;
+
+static const int TILE_WIDTH   = 32;
+static const int TILE_HEIGHT  = TILE_WIDTH / 2;
+static const int WORLD_WIDTH  = 20;
+static const int WORLD_HEIGHT = 20;
+
+static const TileDesc tile_set[] = {
+    {.type   = TileFromColour,
+     .width  = TILE_WIDTH,
+     .height = TILE_HEIGHT,
+     .colour = (Pixel){.r = 0x38, .g = 0x3b, .b = 0x46, .a = 0xff}},
+    {.type   = TileFromColour,
+     .width  = TILE_WIDTH,
+     .height = TILE_HEIGHT,
+     .colour = (Pixel){.r = 0xA5, .g = 0xb3, .b = 0xc0, .a = 0xff}},
+    {.type   = TileFromColour,
+     .width  = TILE_WIDTH,
+     .height = TILE_HEIGHT,
+     .colour = (Pixel){.r = 0xdc, .g = 0x76, .b = 0x84, .a = 0xff}},
+};
+
+typedef enum Colour {
+  Black,
+  White,
+  Red,
+} Colour;
+
+typedef struct GfxAppState {
+  IsoBackend* backend;
+  IsoGfx*     iso;
+  Tile        red;
+  int         xpick;
+  int         ypick;
+} GfxAppState;
+
+static void make_checkerboard(IsoGfx* iso, Tile black, Tile white) {
+  assert(iso);
+  for (int y = 0; y < isogfx_world_height(iso); ++y) {
+    for (int x = 0; x < isogfx_world_width(iso); ++x) {
+      const int  odd_col = x & 1;
+      const int  odd_row = y & 1;
+      const Tile value   = (odd_row ^ odd_col) == 0 ? black : white;
+      isogfx_set_tile(iso, x, y, value);
+    }
+  }
+}
+
+static bool init(GfxAppState* state, int argc, const char** argv) {
+  assert(state);
+
+  (void)argc;
+  (void)argv;
+
+  if (!(state->iso = isogfx_new(&(IsoGfxDesc){
+            .screen_width = SCREEN_WIDTH, .screen_height = SCREEN_HEIGHT}))) {
+    return false;
+  }
+  IsoGfx* iso = state->iso;
+
+  isogfx_resize(iso, SCREEN_WIDTH, SCREEN_HEIGHT);
+
+  if (!isogfx_make_world(
+          iso, &(WorldDesc){
+                   .tile_width   = TILE_WIDTH,
+                   .tile_height  = TILE_HEIGHT,
+                   .world_width  = WORLD_WIDTH,
+                   .world_height = WORLD_HEIGHT})) {
+    return false;
+  }
+
+  const Tile black = isogfx_make_tile(iso, &tile_set[Black]);
+  const Tile white = isogfx_make_tile(iso, &tile_set[White]);
+  state->red       = isogfx_make_tile(iso, &tile_set[Red]);
+  make_checkerboard(iso, black, white);
+
+  if (!(state->backend = IsoBackendInit(iso))) {
+    return false;
+  }
+
+  return true;
+}
+
+static void shutdown(GfxAppState* state) {
+  assert(state);
+
+  IsoBackendShutdown(&state->backend);
+  isogfx_del(&state->iso);
+}
+
+static void update(GfxAppState* state, double t, double dt) {
+  assert(state);
+  (void)dt;
+
+  IsoGfx* iso = state->iso;
+
+  isogfx_update(iso, t);
+
+  // Get mouse position in window coordinates.
+  double mouse_x, mouse_y;
+  gfx_app_get_mouse_position(&mouse_x, &mouse_y);
+
+  // Map from window coordinates to virtual screen coordinates.
+  IsoBackendGetMousePosition(
+      state->backend, mouse_x, mouse_y, &mouse_x, &mouse_y);
+
+  isogfx_pick_tile(iso, mouse_x, mouse_y, &state->xpick, &state->ypick);
+
+  printf("Picked tile: (%d, %d)\n", state->xpick, state->ypick);
+}
+
+static void render(GfxAppState* state) {
+  assert(state);
+
+  IsoGfx* iso = state->iso;
+
+  isogfx_render(iso);
+
+  if ((state->xpick != -1) && (state->ypick != -1)) {
+    isogfx_draw_tile(iso, state->xpick, state->ypick, state->red);
+  }
+
+  IsoBackendRender(state->backend, iso);
+}
+
+static void resize(GfxAppState* state, int width, int height) {
+  assert(state);
+
+  IsoBackendResizeWindow(state->backend, state->iso, width, height);
+}
+
+int main(int argc, const char** argv) {
+  GfxAppState state = {0};
+  gfx_app_run(
+      &(GfxAppDesc){
+          .argc              = argc,
+          .argv              = argv,
+          .width             = WINDOW_WIDTH,
+          .height            = WINDOW_HEIGHT,
+          .max_fps           = MAX_FPS,
+          .update_delta_time = MAX_FPS > 0 ? 1.0 / (double)MAX_FPS : 0.0,
+          .title             = "Isometric Renderer",
+          .app_state         = &state},
+      &(GfxAppCallbacks){
+          .init     = init,
+          .update   = update,
+          .render   = render,
+          .resize   = resize,
+          .shutdown = shutdown});
+  return 0;
+}