diff --git a/README.md b/README.md
index 7105676..9456e30 100644
--- a/README.md
+++ b/README.md
@@ -12,3 +12,18 @@ function order:
 - static functions(ones that don't take object as parameter)
 - empty line
 - methods(ones that do take object as parameter)
+
+## game skunk advance stuffs
+
+do lots automagic...
+magic main function within the header?
+autocalling update and init function.
+texture loading compile time? parse directory, make a variable for each (player.png -> tex_player), and a loading function that will load all of them.
+
+### game skunk advance specs
+8-bit colour, but user changeable palette(realtime)
+tilesize 16x16
+screensize 304x176 (19x11 tiles)
+multiple tilesets... or singular big tileset? the latter... could be a nice simplification... maybe 65536 tiles, a 4096x4096 pixels texture
+4 tilemaps, 1024x1024 each, tileset offsets?, rotation and other effects
+256 sprites (using tileset)
diff --git a/build.bat b/build.bat
index 3bbe4a1..cbae06f 100644
--- a/build.bat
+++ b/build.bat
@@ -2,5 +2,5 @@
 
 REM cd build && cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_EXPORT_COMPILE_COMMANDS=1 -GNinja .. && ninja && copy compile_commands.json .. && skunkworks.exe
 
-cd build && meson compile && copy compile_commands.json .. && skunktest.exe
+cd build && meson compile && copy compile_commands.json .. && cd .. && build\gsa.exe
 
diff --git a/examples/gsa_simple.c b/examples/gsa_simple.c
new file mode 100644
index 0000000..a8b6c7d
--- /dev/null
+++ b/examples/gsa_simple.c
@@ -0,0 +1,16 @@
+#include <gsa.h>
+
+void init() {
+	sprites[0].tile = 2;
+	sprites[0].x = 10;
+	sprites[0].y = 10;
+
+	sprites[1].tile = 3;
+	sprites[1].x = 10;
+	sprites[1].y = 100;
+}
+
+void tick() {
+	sprites[0].x += 1;
+	sprites[1].x += 2;
+}
diff --git a/gfx.png b/gfx.png
new file mode 100644
index 0000000..0491d1a
Binary files /dev/null and b/gfx.png differ
diff --git a/include/color8.h b/include/color8.h
new file mode 100644
index 0000000..3cda90c
--- /dev/null
+++ b/include/color8.h
@@ -0,0 +1,8 @@
+#ifndef GUARD_025B7F5FAD7E029F9A2F84062CDA4F53
+#define GUARD_025B7F5FAD7E029F9A2F84062CDA4F53
+
+#include "types.h"
+
+typedef u8 sw_color8;
+
+#endif /* GUARD_025B7F5FAD7E029F9A2F84062CDA4F53 */
diff --git a/include/gsa.h b/include/gsa.h
new file mode 100644
index 0000000..6a03cd9
--- /dev/null
+++ b/include/gsa.h
@@ -0,0 +1,56 @@
+/************************************************************************/
+/*   ________                        ___________                 __     */
+/*  /  _____/_____    _____   ____  /   _____/  | ____ __  ____ |  | __ */
+/* /   \  ___\__  \  /     \_/ __ \ \_____  \|  |/ /  |  \/    \|  |/ / */
+/* \    \_\  \/ __ \|  Y Y  \  ___/ /        \    <|  |  /   |  \    <  */
+/*  \______  (____  /__|_|  /\___  >_______  /__|_ \____/|___|  /__|_ \ */
+/*         \/     \/      \/     \/        \/     \/          \/     \/ */
+/*            _____       .___                                          */
+/*           /  _  \    __| _/__  _______    ____   ____  ____          */
+/*          /  /_\  \  / __ |\  \/ /\__  \  /    \_/ ___\/ __ \         */
+/*         /    |    \/ /_/ | \   /  / __ \|   |  \  \__\  ___/         */
+/*         \____|__  /\____ |  \_/  (____  /___|  /\___  >___  >        */
+/*                 \/      \/            \/     \/     \/    \/         */
+/************************************************************************/
+
+#ifndef GUARD_73FF49EF137A66E6AAD3A8A1BCF2F2DE
+#define GUARD_73FF49EF137A66E6AAD3A8A1BCF2F2DE
+
+#include "image8.h"
+#ifndef GSA_NOMAIN
+#include "embed_gfx.h"
+#endif
+
+#include "skunkworks.h"
+#include "vec2i.h"
+#include "window.h"
+
+struct gsa_sprite {
+	u16 tile;
+	i32 x, y;
+};
+
+#define MAX_SPRITES 256
+
+extern struct gsa_sprite sprites[MAX_SPRITES];
+extern struct sw_image8 *_gfx;
+
+int gsa_main(int argc, char *argv[]);
+
+/* to be implemented in game */
+
+void init();
+void tick();
+
+#ifndef GSA_NOMAIN
+int main(int argc, char *argv[]) {
+	_gfx = sw_image8_load_png_data(___gfx_png, ___gfx_png_len);
+	gsa_main(argc, argv);
+
+	return 0;
+}
+#endif
+
+void _gsa_tick();
+
+#endif /* GUARD_73FF49EF137A66E6AAD3A8A1BCF2F2DE */
diff --git a/include/image8.h b/include/image8.h
new file mode 100644
index 0000000..3956d3c
--- /dev/null
+++ b/include/image8.h
@@ -0,0 +1,20 @@
+#ifndef GUARD_6AEC99B12E1F76DC4E50DC199E93CDB5
+#define GUARD_6AEC99B12E1F76DC4E50DC199E93CDB5
+
+#include "color8.h"
+#include "vec2i.h"
+
+struct sw_image8 {
+	struct sw_vec2i size;
+	sw_color8 *_data;
+};
+
+struct sw_image8 *sw_image8_create(struct sw_vec2i size);
+void sw_image8_destroy(struct sw_image8 *image);
+
+struct sw_image8 *sw_image8_load_png(char *path);
+struct sw_image8 *sw_image8_load_png_data(u8 *data, u32 data_len);
+
+sw_color8 sw_image8_get(struct sw_image8 *image, struct sw_vec2i pos);
+
+#endif /* GUARD_6AEC99B12E1F76DC4E50DC199E93CDB5 */
diff --git a/include/shader.h b/include/shader.h
new file mode 100644
index 0000000..e48b7a9
--- /dev/null
+++ b/include/shader.h
@@ -0,0 +1,24 @@
+#ifndef GUARD_2AF8C38E79755453C7B276BABE0DA7AE
+#define GUARD_2AF8C38E79755453C7B276BABE0DA7AE
+
+#include "types.h"
+
+struct sw_shader {
+	i32 _shader;
+};
+
+struct sw_shaderprogram {
+	i32 _program;
+};
+
+#define SW_SHADER_VERTEX 1
+#define SW_SHADER_FRAGMENT 2
+
+struct sw_shader sw_shader_create(char const *source, i32 type);
+
+struct sw_shaderprogram
+sw_shaderprogram_create(char const *vertex, char const *fragment);
+
+void sw_shaderprogram_use(struct sw_shaderprogram program);
+
+#endif /* GUARD_2AF8C38E79755453C7B276BABE0DA7AE */
diff --git a/include/skunkworks.h b/include/skunkworks.h
index a32bb5d..31c687d 100644
--- a/include/skunkworks.h
+++ b/include/skunkworks.h
@@ -5,6 +5,7 @@
 #include "error.h"
 #include "file.h"
 #include "image32.h"
+#include "image8.h"
 #include "types.h"
 #include "vec2i.h"
 #include "window.h"
diff --git a/include/types.h b/include/types.h
index e1b0d7d..487df85 100644
--- a/include/types.h
+++ b/include/types.h
@@ -11,5 +11,9 @@ typedef signed long long i64;
 typedef unsigned long long u64;
 typedef float f32;
 typedef double f64;
+typedef i8 bool;
+
+#define true 1
+#define false 0
 
 #endif /* GUARD_649E63003BEAE79ECA2B813C4E131C9A */
diff --git a/include/window.h b/include/window.h
index a09213e..33f5532 100644
--- a/include/window.h
+++ b/include/window.h
@@ -13,6 +13,6 @@ struct sw_window {
 
 struct sw_window *sw_window_create(struct sw_vec2i size, char *title);
 
-void sw_window_run(struct sw_window *window);
+void sw_window_run(struct sw_window *window, void (*callback)());
 
 #endif /* GUARD_F247452E0BF1EC9CD9131C2A6FD281CA */
diff --git a/meson.build b/meson.build
index 6b062c3..250da70 100644
--- a/meson.build
+++ b/meson.build
@@ -43,18 +43,29 @@ skunk_sources = [
 	'src/color32.c',
 	'src/error.c',
 	'src/file.c',
+	'src/gsa.c',
 	'src/image32.c',
+	'src/image8.c',
+	'src/shader.c',
 	'src/skunkworks.c',
-	'src/test.c',
 	'src/vec2i.c',
 	'src/window.c'
 ]
 
+xxd = find_program('xxd')
+embed_gfx = custom_target('embed-gfx', input: ['gfx.png'], output: ['embed_gfx.h'],
+		  command: [xxd, '-i', '@INPUT@', '@OUTPUT@'])
+
 add_project_arguments('-D_CRT_SECURE_NO_WARNINGS', language : 'c')
+add_project_arguments('-Wall', language : 'c')
+add_project_arguments('-Wextra', language : 'c')
+add_project_arguments('-Werror', language : 'c')
 
 
 if host_machine.system() == 'emscripten'
    executable('skunktest', skunk_sources, include_directories: 'include', dependencies: deps, link_args: ['-lglfw', '-lGL', '-s', 'USE_GLFW=3'], name_suffix: 'html')
 else
-	executable('skunktest', skunk_sources, include_directories: 'include', dependencies: deps)
+	lib = static_library('skunkworks', skunk_sources, include_directories: 'include', dependencies: deps)
+	executable('skunktest', 'src/test.c', link_with: lib, include_directories: 'include', dependencies: deps)
+	executable('gsa', 'examples/gsa_simple.c', embed_gfx, link_with: lib, include_directories: 'include', dependencies: deps)
 endif
\ No newline at end of file
diff --git a/src/gsa.c b/src/gsa.c
new file mode 100644
index 0000000..fa93b0d
--- /dev/null
+++ b/src/gsa.c
@@ -0,0 +1,185 @@
+#include "error.h"
+#include "gl.h"
+#include "image8.h"
+#include "shader.h"
+#include <gl/gl.h>
+#define GSA_NOMAIN
+#include "gsa.h"
+
+struct gsa_sprite sprites[256];
+
+struct sw_image8 *_gfx;
+struct sw_window *_win;
+
+static char *vert_source = "#version 450\n\
+in vec2 pos;\
+in vec2 tex_coord;\
+layout(location = 0) out vec2 out_tex_coord;\
+void main() {\
+gl_Position = vec4((pos / vec2(152, -88)) - vec2(1, -1), 0.f, 1.f);\
+out_tex_coord = tex_coord;\
+}\
+";
+
+static char *frag_source = "#version 450\n\
+layout(location = 0) in vec2 tex_coord;\
+uniform sampler2D tex;\
+out vec4 color;\
+void main(){\
+float r = texture(tex, tex_coord).r;\
+if(r > 0)\
+color = vec4(0.9, 0.2, 0.1, 1.0);\
+}\
+";
+
+static struct sw_shaderprogram program;
+
+static u32 vbo, vao;
+
+#define MAX_RENDER_VERTS 60
+
+struct render_vert {
+	f32 x, y, tx, ty;
+};
+
+static i32 next_render_vert;
+static struct render_vert render_verts[MAX_RENDER_VERTS * 4];
+
+int gsa_main(int argc, char *argv[]) {
+	(void)argc;
+	(void)argv;
+	u32 tex;
+	struct sw_image8 *img;
+
+	sw_log("Initialising GameSkunkAdvance v0.0");
+
+	_win = sw_window_create(sw_vec2i(304, 176), "Game Skunk Advance v0.0");
+	program = sw_shaderprogram_create(vert_source, frag_source);
+	sw_shaderprogram_use(program);
+
+	img = sw_image8_load_png("gfx.png");
+	glGenTextures(1, &tex);
+	glBindTexture(GL_TEXTURE_2D, tex);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+	glTexImage2D(
+	    GL_TEXTURE_2D,
+	    0,
+	    GL_RED,
+	    4096,
+	    4096,
+	    0,
+	    GL_RED,
+	    GL_UNSIGNED_BYTE,
+	    img->_data
+	);
+	sw_image8_destroy(img);
+
+	glGenBuffers(1, &vao);
+	glBindVertexArray(vao);
+
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glVertexAttribPointer(
+	    glGetAttribLocation(program._program, "pos"),
+	    2,
+	    GL_FLOAT,
+	    GL_FALSE,
+	    sizeof(struct render_vert),
+	    0
+	);
+	glVertexAttribPointer(
+	    glGetAttribLocation(program._program, "tex_coord"),
+	    2,
+	    GL_FLOAT,
+	    GL_FALSE,
+	    sizeof(struct render_vert),
+	    (void *)(2 * sizeof(float))
+	);
+	glEnableVertexAttribArray(glGetAttribLocation(program._program, "pos"));
+	glEnableVertexAttribArray(glGetAttribLocation(program._program, "tex_coord")
+	);
+
+	init();
+	sw_window_run(_win, _gsa_tick);
+
+	return 0;
+}
+
+static void rect(f32 x, f32 y, f32 w, f32 h, i16 tile) {
+	f32 tx, ty, ts;
+
+	tx = ((tile % 256) * 16.f) / 4096.f;
+	ty = ((tile / 256) * 16.f) / 4096.f;
+	ts = 1.f / 256.f;
+
+	if(next_render_vert >= MAX_RENDER_VERTS) {
+		sw_error(
+		    "trying to draw more than the current max of %i vertices in a "
+		    "frame",
+		    MAX_RENDER_VERTS
+		);
+	}
+
+	sw_log("tx %f | ty %f | ts %f", tx, ty, ts);
+
+	render_verts[next_render_vert].x = x;
+	render_verts[next_render_vert].y = y;
+	render_verts[next_render_vert].tx = tx;
+	render_verts[next_render_vert].ty = ty;
+	++next_render_vert;
+
+	render_verts[next_render_vert].x = x + w;
+	render_verts[next_render_vert].y = y;
+	render_verts[next_render_vert].tx = tx + ts;
+	render_verts[next_render_vert].ty = ty;
+	++next_render_vert;
+
+	render_verts[next_render_vert].x = x;
+	render_verts[next_render_vert].y = y + h;
+	render_verts[next_render_vert].tx = tx;
+	render_verts[next_render_vert].ty = ty + ts;
+	++next_render_vert;
+
+	render_verts[next_render_vert].x = x + w;
+	render_verts[next_render_vert].y = y;
+	render_verts[next_render_vert].tx = tx + ts;
+	render_verts[next_render_vert].ty = ty;
+	++next_render_vert;
+
+	render_verts[next_render_vert].x = x;
+	render_verts[next_render_vert].y = y + h;
+	render_verts[next_render_vert].tx = tx;
+	render_verts[next_render_vert].ty = ty + ts;
+	++next_render_vert;
+
+	render_verts[next_render_vert].x = x + w;
+	render_verts[next_render_vert].y = y + h;
+	render_verts[next_render_vert].tx = tx + ts;
+	render_verts[next_render_vert].ty = ty + ts;
+	++next_render_vert;
+}
+
+void _gsa_tick() {
+	i32 i;
+
+	tick();
+
+	next_render_vert = 0;
+	/* glBegin(GL_TRIANGLES); */
+	for(i = 0; i < MAX_SPRITES; ++i) {
+		if(sprites[i].tile > 0) {
+			rect(sprites[i].x, sprites[i].y, 16, 16, sprites[i].tile);
+		}
+	}
+
+	glBindVertexArray(vao);
+	glBufferData(
+	    GL_ARRAY_BUFFER,
+	    sizeof(struct render_vert) * (next_render_vert),
+	    render_verts,
+	    GL_DYNAMIC_DRAW
+	);
+	glDrawArrays(GL_TRIANGLES, 0, next_render_vert);
+	/* glEnd(); */
+}
diff --git a/src/image32.c b/src/image32.c
index 7a6ba33..47af531 100644
--- a/src/image32.c
+++ b/src/image32.c
@@ -43,7 +43,7 @@ struct sw_image32 *sw_image32_load_png_data(u8 *data, u32 data_len) {
 	u32 width, height;
 	u8 color_type, bit_depth;
 	u8 **row_pointers;
-	i32 i;
+	u32 i;
 
 	buf = malloc(sizeof(struct sw_filebuffer));
 	buf->_data = data;
diff --git a/src/image8.c b/src/image8.c
new file mode 100644
index 0000000..804be36
--- /dev/null
+++ b/src/image8.c
@@ -0,0 +1,111 @@
+#include "image8.h"
+
+#include <stdlib.h>
+
+#include "error.h"
+#include "file.h"
+#include "png.h"
+#include "vec2i.h"
+
+void png_read_fn(png_structp png, png_bytep out, png_size_t count);
+
+struct sw_image8 *sw_image8_create(struct sw_vec2i size) {
+	struct sw_image8 *image;
+
+	image = malloc(sizeof(struct sw_image8));
+	image->_data = malloc(sizeof(sw_color8) * size.x * size.y);
+	image->size = size;
+
+	return image;
+}
+
+void sw_image8_destroy(struct sw_image8 *image) {
+	free(image->_data);
+	free(image);
+}
+
+struct sw_image8 *sw_image8_load_png(char *path) {
+	u32 size;
+	u8 *data;
+	struct sw_image8 *image;
+
+	data = sw_file_load(path, &size);
+	image = sw_image8_load_png_data(data, size);
+	free(data);
+	return image;
+}
+
+struct sw_image8 *sw_image8_load_png_data(u8 *data, u32 data_len) {
+	struct sw_image8 *img;
+	struct sw_filebuffer *buf;
+	png_structp png;
+	png_infop info;
+	u32 width, height;
+	u8 color_type, bit_depth;
+	u8 **row_pointers;
+	u32 i;
+
+	buf = malloc(sizeof(struct sw_filebuffer));
+	buf->_data = data;
+	buf->pos = 0;
+	buf->size = data_len;
+
+	if(png_sig_cmp(data, 0, 8)) {
+		sw_error("File isn't recognised as a PNG file");
+	}
+
+	/* TODO: add error handles? <_< */
+	png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
+	info = png_create_info_struct(png);
+	png_set_read_fn(png, buf, png_read_fn);
+	png_read_info(png, info);
+
+	width = png_get_image_width(png, info);
+	height = png_get_image_height(png, info);
+	color_type = png_get_color_type(png, info);
+	bit_depth = png_get_bit_depth(png, info);
+
+	sw_log(
+	    "loading image of size %ux%u, color_type %u, bit_depth %u",
+	    width,
+	    height,
+	    color_type,
+	    bit_depth
+	);
+
+	if(color_type != PNG_COLOR_TYPE_PALETTE) {
+		sw_error("image8 can only load palette files");
+	}
+
+	if(bit_depth != 8) {
+		sw_error("image32 can currently only load 8 bit files");
+	}
+
+	img = sw_image8_create(sw_vec2i(width, height));
+
+	row_pointers = malloc(sizeof(u8 *) * height);
+	for(i = 0; i < height; ++i) {
+		row_pointers[i] = (u8 *)(img->_data + width * i);
+	}
+	png_read_image(png, row_pointers);
+
+	free(row_pointers);
+	free(buf);
+
+	/* TODO: cleanup of png structs? */
+
+	return img;
+}
+
+sw_color8 sw_image8_get(struct sw_image8 *image, struct sw_vec2i pos) {
+	return image->_data[pos.x + pos.y * image->size.x];
+}
+
+/* private */
+
+void png_read_fn(png_structp png, png_bytep out, png_size_t count) {
+	struct sw_filebuffer *buf;
+
+	buf = png_get_io_ptr(png);
+	sw_filebuffer_read(buf, out, count);
+}
diff --git a/src/shader.c b/src/shader.c
new file mode 100644
index 0000000..487778f
--- /dev/null
+++ b/src/shader.c
@@ -0,0 +1,60 @@
+#include "shader.h"
+
+#include <string.h>
+
+#include "error.h"
+#include "gl.h"
+
+struct sw_shader sw_shader_create(char const *source, i32 type) {
+	struct sw_shader shader;
+	i32 gltype;
+	i32 length;
+	i32 ret;
+
+	switch(type) {
+	case SW_SHADER_VERTEX:
+		gltype = GL_VERTEX_SHADER;
+		break;
+	case SW_SHADER_FRAGMENT:
+		gltype = GL_FRAGMENT_SHADER;
+		break;
+	default:
+		gltype = 0;
+		sw_error("unknown shader type");
+	}
+
+	shader._shader = glCreateShader(gltype);
+	length = strlen(source);
+	glShaderSource(shader._shader, 1, &source, &length);
+	glCompileShader(shader._shader);
+
+	glGetShaderiv(shader._shader, GL_COMPILE_STATUS, &ret);
+	if(!ret) {
+		char str[256];
+		i32 len;
+
+		glGetShaderInfoLog(shader._shader, 256, &len, str);
+		sw_error("Shader Compile Error: %s", str);
+	}
+
+	return shader;
+}
+
+struct sw_shaderprogram
+sw_shaderprogram_create(char const *vertex, char const *fragment) {
+	struct sw_shaderprogram program;
+	struct sw_shader v, f;
+
+	v = sw_shader_create(vertex, SW_SHADER_VERTEX);
+	f = sw_shader_create(fragment, SW_SHADER_FRAGMENT);
+	program._program = glCreateProgram();
+	glAttachShader(program._program, v._shader);
+	glAttachShader(program._program, f._shader);
+	glLinkProgram(program._program);
+
+	return program;
+}
+
+void sw_shaderprogram_use(struct sw_shaderprogram program) {
+	glUseProgram(program._program);
+}
diff --git a/src/skunkworks.h b/src/skunkworks.h
index ead3db9..06433c3 100644
--- a/src/skunkworks.h
+++ b/src/skunkworks.h
@@ -1,3 +1,12 @@
+/***************************************************************************/
+/*   ___________                 __                         __             */
+/*  /   _____/  | ____ __  ____ |  | ____  _  _____________|  | __  ______ */
+/*  \_____  \|  |/ /  |  \/    \|  |/ /\ \/ \/ /  _ \_  __ \  |/ / /  ___/ */
+/*  /        \    <|  |  /   |  \    <  \     (  <_> )  | \/    <  \___ \  */
+/* /_______  /__|_ \____/|___|  /__|_ \  \/\_/ \____/|__|  |__|_ \/____  > */
+/*         \/     \/          \/     \/                         \/     \/  */
+/***************************************************************************/
+
 #ifndef GUARD_BAEE408B8F416CA55711305ABAF9CE6C
 #define GUARD_BAEE408B8F416CA55711305ABAF9CE6C
 
diff --git a/src/test.c b/src/test.c
index d65a6e6..2936610 100644
--- a/src/test.c
+++ b/src/test.c
@@ -14,13 +14,17 @@ void tick();
 int main(int argc, char *argv[]) {
 	struct sw_image32 *img;
 
-	sw_init();
-	printf("hello world\n");
-	win = sw_window_create(sw_vec2i(640, 480), "Skunkworks");
+	(void)argc;
+	(void)argv;
 
+	sw_init();
+	win = sw_window_create(sw_vec2i(640, 480), "Skunkworks");
 	img = sw_image32_load_png("d:/art/pfp.png");
 	sw_debug("%08X", sw_image32_get(img, sw_vec2i(10, 10)));
+	sw_window_run(win, tick);
 
-	sw_window_run(win);
 	return 0;
 }
+
+void tick() {
+}
diff --git a/src/window.c b/src/window.c
index 555e5ba..1db09b1 100644
--- a/src/window.c
+++ b/src/window.c
@@ -4,8 +4,9 @@
 
 #include "gl.h"
 
-void tick();
-struct sw_window *tick_window;
+void _tick();
+struct sw_window *_tick_window;
+void (*_tick_fn)();
 
 struct sw_window *sw_window_create(struct sw_vec2i size, char *title) {
 	struct sw_window *win;
@@ -29,21 +30,23 @@ struct sw_window *sw_window_create(struct sw_vec2i size, char *title) {
 	return win;
 }
 
-void sw_window_run(struct sw_window *window) {
-	tick_window = window;
+void sw_window_run(struct sw_window *window, void (*callback)()) {
+	_tick_window = window;
+	_tick_fn = callback;
 #ifdef __EMSCRIPTEN__
-	emscripten_set_main_loop(tick, 60, 1);
+	emscripten_set_main_loop(_tick, 60, 1);
 #else
 	while(!glfwWindowShouldClose(window->_window)) {
-		tick();
+		_tick();
 	}
 #endif
 }
 
 /* private functions */
 
-void tick() {
-	glClear(GL_COLOR_BUFFER_BIT);
-	glfwSwapBuffers(tick_window->_window);
+void _tick() {
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	_tick_fn();
+	glfwSwapBuffers(_tick_window->_window);
 	glfwPollEvents();
 }