refactor file structure

src/engine/engine.c

@@ -1,4 +1,6 @@
-#include "engine.h"
+#include <dangerzone/engine.h>
+
+#include "internal/engine_internal.h"
 
 engine_internal_state_t *internal_state = NULL;
 game_state_t *game_state = NULL;

src/engine/engine_init.c

@@ -1,8 +1,7 @@
-#include "engine.h"
-#include "error.h"
-#include <SDL3/SDL_render.h>
-#include <SDL3/SDL_video.h>
-#include <stdint.h>
+#include <dangerzone/engine.h>
+
+#include "internal/engine_internal.h"
+#include "internal/util/error.h"
 
 bool
 engine_sdl_init_state(

src/engine/render/misc.c

@@ -0,0 +1,48 @@
+#include <dangerzone/engine.h>
+#include <dangerzone/render/misc.h>
+#include <dangerzone/render/rect.h>
+
+#include "internal/util/error.h"
+#include <stdint.h>
+
+// alter a pixel at an imaginary x & y coordinates
+void 
+put_pixel(
+	unsigned int x, 
+	unsigned int y, 
+	uint32_t color
+) {
+	uint16_t w = game_state->width;
+	uint16_t h = game_state->height;
+
+	if (x < 0 || x >= w || y < 0 || y >= h) {
+		eprintf(
+			"CRITICAL: attempted buffer overflow in put_pixel\n"
+			"at x = %d, y = %d", x, y
+		);
+	} else {
+		game_state->framebuffer[game_state->width * y + x]
+			= color;
+
+	    mark_dirty_rect(x, y, 1, 1);
+	}
+}
+
+// fill the entire framebuffer with a given color
+void
+clear_framebuffer(
+	uint32_t color
+) {
+    for (size_t i = 0;
+         i < (size_t)game_state->width * game_state->height;
+         ++i) {
+        game_state->framebuffer[i] = color;
+    }
+
+    mark_dirty_rect(
+        0,
+        0,
+        game_state->width,
+        game_state->height
+    );
+}

src/engine/render/rect.c

@@ -1,30 +1,9 @@
-#include "engine.h"
-#include "error.h"
+#include <dangerzone/engine.h>
+#include <dangerzone/render/misc.h>
+#include <dangerzone/render/rect.h>
+
 #include <stdint.h>
 
-// alter a pixel at an imaginary x & y coordinates
-void 
-put_pixel(
-	unsigned int x, 
-	unsigned int y, 
-	uint32_t color
-) {
-	uint16_t w = game_state->width;
-	uint16_t h = game_state->height;
-
-	if (x < 0 || x >= w || y < 0 || y >= h) {
-		eprintf(
-			"CRITICAL: attempted buffer overflow in put_pixel\n"
-			"at x = %d, y = %d", x, y
-		);
-	} else {
-		game_state->framebuffer[game_state->width * y + x]
-			= color;
-
-	    mark_dirty_rect(x, y, 1, 1);
-	}
-}
-
 /**
  * draws a rectangle with its left-top corner at (x,y) with
  * a width of 'w' and height of 'h' filled with color 'color'
@@ -45,25 +24,6 @@ put_rect(
 	mark_dirty_rect(x, y, w, h);
 }
 
-// fill the entire framebuffer with a given color
-void
-clear_framebuffer(
-	uint32_t color
-) {
-    for (size_t i = 0;
-         i < (size_t)game_state->width * game_state->height;
-         ++i) {
-        game_state->framebuffer[i] = color;
-    }
-
-    mark_dirty_rect(
-        0,
-        0,
-        game_state->width,
-        game_state->height
-    );
-}
-
 void
 clear_rect(int x, int y, int w, int h, uint32_t color)
 {

src/engine/render/text.c

@@ -1,7 +1,10 @@
 // rendering characters in the framebuffer
 
-#include "engine.h"
-#include <stdint.h>
+#include <dangerzone/engine.h>
+#include <dangerzone/render/rect.h>
+#include <dangerzone/render/text.h>
+
+#include "internal/engine_internal.h"
 
 /*
  * each character has 8 rows

src/examples/window.c

@@ -1,4 +1,6 @@
-#include "engine.h"
+#include <dangerzone/engine.h>
+#include <dangerzone/render/misc.h>
+#include <dangerzone/render/text.h>
 
 // polling events every frame
 void

src/internal/engine_internal.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include <SDL3/SDL.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+
+#define WINDOW_NAME_MAX_LENGTH 128
+#define FONT_ROWS 7
+#define FONT_COLS 5
+
+typedef struct {
+	char window_name[WINDOW_NAME_MAX_LENGTH];
+	uint16_t width, height;
+	SDL_Window *window;
+	SDL_Renderer *renderer;
+	SDL_Texture *texture;
+} engine_sdl_state_t;
+
+typedef struct {
+	/**
+	 * this function runs inside of the SDL_PollEvent loop
+	 * useful for user input, quitting the program and so on
+	 */
+	void (*engine_poll_events)(void);
+	/**
+	 * meant as the "area" for manupulating the framebuffer;
+	 * after this is executed, the contents of 
+	 * game_state->framebuffer get drawn
+	 */
+	void (*engine_update_framebuffer)(void);
+	engine_sdl_state_t *sdl_state;
+} engine_internal_state_t;
+
+extern engine_internal_state_t *internal_state;
+
+engine_sdl_state_t*
+engine_sdl_init(
+	uint32_t window_width,
+	uint32_t window_height,
+	const char window_name[]
+);
+
+void 
+engine_sdl_destroy(
+	engine_sdl_state_t *state
+);

src/internal/util/error.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <stdio.h>
+#include <stdbool.h>
+
+#define eprintf(fmt, ...) \
+	fprintf(stderr, "[ERROR] " fmt "\n", ##__VA_ARGS__)
+
+#define RCODE_FAILURE false
+#define RCODE_SUCCESS true