Initial commit

3 files changed, 195 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..bfb6190
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,2 @@
+main: src/all.c src/all.h
+	gcc -Wall -Wextra -Wpedantic -DSDL $$(pkg-config --libs sdl3) -o main src/all.c
diff --git a/src/all.c b/src/all.c
new file mode 100644
index 0000000..f14a3d2
--- /dev/null
+++ b/src/all.c
@@ -0,0 +1,180 @@
+#include "all.h"
+
+#define MEM_SIZE (1<<16)
+
+typedef struct {
+	char *start;
+	char *end;
+} Arena;
+
+#define new(a, c, t) ((t *) alloc(a, c, sizeof(t), _Alignof(t)))
+#define affirm(c) while (!(c)) *(volatile int *)0 = 0
+
+static void *alloc(Arena *a, ptrdiff_t count, ptrdiff_t size, ptrdiff_t align) {
+	ptrdiff_t pad = -(size_t) a->start & (align - 1);
+	affirm(count < (a->end - a->start - pad) / size);
+	char *r = a->start + pad;
+	a->start += pad + size * count;
+	for (ptrdiff_t i = 0; i < count * size; i++) {
+		r[i] = 0;
+	}
+
+	return r;
+}
+
+typedef struct {
+	int width, height;
+} UI;
+
+typedef struct {
+	int x, y;
+} State;
+
+enum {
+	INPUT_NONE,
+	INPUT_UP,
+	INPUT_DOWN,
+	INPUT_LEFT,
+	INPUT_RIGHT,
+};
+
+typedef struct {
+	State state;
+	UI ui;
+	int input;
+} Game;
+
+static DrawList *render(State state, UI *ui, Arena *a) {
+	(void) ui;
+
+	DrawList *drawList = new(a, 1, DrawList);
+	drawList->len = 1;
+	drawList->els[0] = (DrawElement) {
+		.rect = (SDL_Rect) {
+			.x = state.x,
+			.y = state.y,
+			.w = 100,
+			.h = 100,
+		},
+		.color = (SDL_Color) {
+			.r = 255,
+			.g = 0,
+			.b = 0,
+			.a = 255,
+		},
+	};
+
+	return drawList;
+}
+
+static void update(Game *game, Arena a) {
+	switch (game->input) {
+		case INPUT_UP:
+			game->state.y -= 20;
+			break;
+		case INPUT_DOWN:
+			game->state.y += 20;
+			break;
+		case INPUT_LEFT:
+			game->state.x -= 20;
+			break;
+		case INPUT_RIGHT:
+			game->state.x += 20;
+			break;
+		default:
+			break;
+	}
+}
+
+#if SDL
+
+int main(int argc, char **argv) {
+	(void) argc;
+	(void) argv;
+
+	char *mem = SDL_malloc(MEM_SIZE);
+	Arena a = {
+		.start = mem,
+		.end = mem + MEM_SIZE,
+	};
+
+	Game *game = new(&a, 1, Game);
+	game->state = (State) {
+		.x = 100,
+		.y = 100,
+	};
+	game->ui = (UI) {
+		.width = 640,
+		.height = 480,
+	};
+
+	SDL_Init(SDL_INIT_VIDEO);
+	SDL_Window *w = SDL_CreateWindow(
+		"LDJam 57",
+		game->ui.width,
+		game->ui.height,
+		0
+	);
+	SDL_PropertiesID renderProps = SDL_CreateProperties();
+	SDL_SetPointerProperty(renderProps, SDL_PROP_RENDERER_CREATE_WINDOW_POINTER, w);
+	SDL_SetNumberProperty(renderProps, SDL_PROP_RENDERER_CREATE_PRESENT_VSYNC_NUMBER, 1);
+	SDL_Renderer *r = SDL_CreateRendererWithProperties(renderProps);
+	SDL_DestroyProperties(renderProps);
+	
+	for (;;) {
+		game->input = INPUT_NONE;
+		SDL_Event e = {0};
+		while (SDL_PollEvent(&e)) {
+			switch (e.type) {
+				case SDL_EVENT_QUIT:
+					return 0;
+				case SDL_EVENT_KEY_DOWN:
+					switch (e.key.key) {
+						case 'w':
+							game->input = INPUT_UP;
+							break;
+						case 'a':
+							game->input = INPUT_LEFT;
+							break;
+						case 's':
+							game->input = INPUT_DOWN;
+							break;
+						case 'd':
+							game->input = INPUT_RIGHT;
+							break;
+					}
+					break;
+			}
+		}
+
+		Arena scratch = a;
+		DrawList *drawList = render(game->state, &game->ui, &scratch);
+		SDL_SetRenderDrawColor(r, 0, 0, 0, 255);
+		SDL_RenderFillRect(r, NULL);
+		for (int i = 0; i < drawList->len; i++) {
+			SDL_SetRenderDrawColor(
+				r,
+				drawList->els[i].color.r,
+				drawList->els[i].color.g,
+				drawList->els[i].color.b,
+				drawList->els[i].color.a
+			);
+			SDL_FRect rect = {
+				.x = (float) drawList->els[i].rect.x,
+				.y = (float) drawList->els[i].rect.y,
+				.w = (float) drawList->els[i].rect.w,
+				.h = (float) drawList->els[i].rect.h
+			};
+			SDL_RenderFillRect(r, &rect);
+		}
+
+		update(game, a);
+
+		SDL_RenderPresent(r);
+	}
+
+	return 0;
+}
+
+#elif WASM
+#endif
diff --git a/src/all.h b/src/all.h
new file mode 100644
index 0000000..19cc6e5
--- /dev/null
+++ b/src/all.h
@@ -0,0 +1,13 @@
+#include <SDL3/SDL.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct {
+	SDL_Rect rect;
+	SDL_Color color;
+} DrawElement;
+
+typedef struct {
+	int len;
+	DrawElement els[256];
+} DrawList;