diff --git a/res/block_.png b/res/block_.png
new file mode 100644
index 00000000..d4941919
Binary files /dev/null and b/res/block_.png differ
diff --git a/res/block_white.png b/res/block_white.png
new file mode 100644
index 00000000..cfb6a408
Binary files /dev/null and b/res/block_white.png differ
diff --git a/res/main.glslv b/res/main.glslv
index f2b67588..1e1cb98a 100644
--- a/res/main.glslv
+++ b/res/main.glslv
@@ -7,15 +7,16 @@ layout (location = 2) in vec4 v_light;
 out vec4 a_color;
 out vec2 a_texCoord;
 
-uniform mat4 model;
-uniform mat4 projview;
+uniform mat4 u_model;
+uniform mat4 u_projview;
+uniform vec3 u_skyLightColor;
+uniform float u_gamma;
 
 void main(){
-	vec4 position = projview * model * vec4(v_position, 1.0);
-	a_color = vec4(v_light.r,v_light.g,v_light.b,1.0f);
+	vec4 position = u_projview * u_model * vec4(v_position, 1.0);
+	a_color = vec4(pow(v_light.rgb, vec3(u_gamma)),1.0f);
 	a_texCoord = v_texCoord;
-	a_color.rgb += v_light.a;
+	a_color.rgb += u_skyLightColor * v_light.a*0.5;
 	a_color.rgb *= 1.0-position.z*0.0025;
-	//a_color.rgb = pow(a_color.rgb, vec3(1.0/0.7));
 	gl_Position = position;
 }
diff --git a/src/files/WorldFiles.cpp b/src/files/WorldFiles.cpp
index d4a8c7e3..6df02573 100644
--- a/src/files/WorldFiles.cpp
+++ b/src/files/WorldFiles.cpp
@@ -14,6 +14,8 @@ union {
 #include <fstream>
 #include <iostream>
 
+unsigned long WorldFiles::totalCompressed = 0;
+
 int bytes2Int(const unsigned char* src, unsigned int offset){
 	return (src[offset] << 24) | (src[offset+1] << 16) | (src[offset+2] << 8) | (src[offset+3]);
 }
@@ -26,11 +28,13 @@ void int2Bytes(int value, char* dest, unsigned int offset){
 }
 
 WorldFiles::WorldFiles(const char* directory, size_t mainBufferCapacity) : directory(directory){
-	mainBuffer = new char[mainBufferCapacity];
+	mainBufferIn = new char[CHUNK_VOL*2];
+	mainBufferOut = new char[mainBufferCapacity];
 }
 
 WorldFiles::~WorldFiles(){
-	delete[] mainBuffer;
+	delete[] mainBufferIn;
+	delete[] mainBufferOut;
 	std::unordered_map<long, char**>::iterator it;
 	for (it = regions.begin(); it != regions.end(); it++){
 	    char** region = it->second;
@@ -66,9 +70,11 @@ void WorldFiles::put(const char* chunkData, int x, int y){
 	if (targetChunk == nullptr){
 		targetChunk = new char[CHUNK_VOL];
 		region[localY * REGION_SIZE + localX] = targetChunk;
+		totalCompressed += CHUNK_VOL;
 	}
 	for (unsigned int i = 0; i < CHUNK_VOL; i++)
 		targetChunk[i] = chunkData[i];
+
 }
 
 std::string WorldFiles::getRegionFile(int x, int y) {
@@ -123,19 +129,19 @@ bool WorldFiles::readChunk(int x, int y, char* out){
 	input.read((char*)(&offset), 4);
 	// Ordering bytes from big-endian to machine order (any, just reading)
 	offset = bytes2Int((const unsigned char*)(&offset), 0);
+	assert (offset < 1000000);
 	if (offset == 0){
 		input.close();
 		return false;
 	}
-
 	input.seekg(offset);
 	input.read((char*)(&offset), 4);
 	size_t compressedSize = bytes2Int((const unsigned char*)(&offset), 0);
 
-	input.read(mainBuffer, compressedSize);
+	input.read(mainBufferIn, compressedSize);
 	input.close();
 
-	decompressRLE(mainBuffer, compressedSize, out, CHUNK_VOL);
+	decompressRLE(mainBufferIn, compressedSize, out, CHUNK_VOL);
 
 	return true;
 }
@@ -150,8 +156,8 @@ void WorldFiles::write(){
 		int y;
 		longToCoords(x,y, it->first);
 
-		unsigned int size = writeRegion(mainBuffer, x,y, it->second);
-		write_binary_file(getRegionFile(x,y), mainBuffer, size);
+		unsigned int size = writeRegion(mainBufferOut, x,y, it->second);
+		write_binary_file(getRegionFile(x,y), mainBufferOut, size);
 	}
 }
 
@@ -165,8 +171,11 @@ unsigned int WorldFiles::writeRegion(char* out, int x, int y, char** region){
 		char* chunk = region[i];
 		if (chunk == nullptr){
 			chunk = new char[CHUNK_VOL];
+			assert((((i % REGION_SIZE) + x * REGION_SIZE) >> REGION_SIZE_BIT) == x);
+			assert((((i / REGION_SIZE) + y * REGION_SIZE) >> REGION_SIZE_BIT) == y);
 			if (readChunk((i % REGION_SIZE) + x * REGION_SIZE, (i / REGION_SIZE) + y * REGION_SIZE, chunk)){
 				region[i] = chunk;
+				totalCompressed += CHUNK_VOL;
 			} else {
 				delete[] chunk;
 				chunk = nullptr;
diff --git a/src/files/WorldFiles.h b/src/files/WorldFiles.h
index bc816adf..7cde5a42 100644
--- a/src/files/WorldFiles.h
+++ b/src/files/WorldFiles.h
@@ -15,9 +15,11 @@
  * */
 class WorldFiles {
 public:
+	static unsigned long totalCompressed;
 	std::unordered_map<long, char**> regions;
 	std::string directory;
-	char* mainBuffer;
+	char* mainBufferIn;
+	char* mainBufferOut;
 
 	WorldFiles(const char* directory, size_t mainBufferCapacity);
 	~WorldFiles();
diff --git a/src/graphics/Shader.cpp b/src/graphics/Shader.cpp
index 34108c55..fbfc17bd 100644
--- a/src/graphics/Shader.cpp
+++ b/src/graphics/Shader.cpp
@@ -26,6 +26,27 @@ void Shader::uniformMatrix(std::string name, glm::mat4 matrix){
 	glUniformMatrix4fv(transformLoc, 1, GL_FALSE, glm::value_ptr(matrix));
 }
 
+void Shader::uniform1i(std::string name, int x){
+	GLuint transformLoc = glGetUniformLocation(id, name.c_str());
+	glUniform1i(transformLoc, x);
+}
+
+void Shader::uniform1f(std::string name, float x){
+	GLuint transformLoc = glGetUniformLocation(id, name.c_str());
+	glUniform1f(transformLoc, x);
+}
+
+void Shader::uniform2f(std::string name, float x, float y){
+	GLuint transformLoc = glGetUniformLocation(id, name.c_str());
+	glUniform2f(transformLoc, x, y);
+}
+
+void Shader::uniform3f(std::string name, float x, float y, float z){
+	GLuint transformLoc = glGetUniformLocation(id, name.c_str());
+	glUniform3f(transformLoc, x,y,z);
+}
+
+
 
 Shader* load_shader(std::string vertexFile, std::string fragmentFile) {
 	// Reading Files
diff --git a/src/graphics/Shader.h b/src/graphics/Shader.h
index baed340d..9507d348 100644
--- a/src/graphics/Shader.h
+++ b/src/graphics/Shader.h
@@ -13,6 +13,10 @@ public:
 
 	void use();
 	void uniformMatrix(std::string name, glm::mat4 matrix);
+	void uniform1i(std::string name, int x);
+	void uniform1f(std::string name, float x);
+	void uniform2f(std::string name, float x, float y);
+	void uniform3f(std::string name, float x, float y, float z);
 };
 
 extern Shader* load_shader(std::string vertexFile, std::string fragmentFile);
diff --git a/src/lighting/LightSolver.cpp b/src/lighting/LightSolver.cpp
index 1ec493a8..c101539c 100644
--- a/src/lighting/LightSolver.cpp
+++ b/src/lighting/LightSolver.cpp
@@ -1,3 +1,4 @@
+#include <assert.h>
 #include "LightSolver.h"
 #include "Lightmap.h"
 #include "../voxels/Chunks.h"
@@ -24,6 +25,7 @@ void LightSolver::add(int x, int y, int z, int emission) {
 }
 
 void LightSolver::add(int x, int y, int z) {
+	assert (chunks != nullptr);
 	add(x,y,z, chunks->getLight(x,y,z, channel));
 }
 
diff --git a/src/loaders/png_loading.cpp b/src/loaders/png_loading.cpp
index 9d69322b..c101632c 100644
--- a/src/loaders/png_loading.cpp
+++ b/src/loaders/png_loading.cpp
@@ -1,17 +1,15 @@
-/*
- * png_loading.cpp
- *
- *  Created on: Feb 10, 2020
- *      Author: MihailRis
- */
-
 #include "png_loading.h"
 
 #include <iostream>
 #include <GL/glew.h>
-#include <png.h>
 #include "../graphics/Texture.h"
 
+// comment line below for use spng instead of libpng
+#define LIBPNG
+
+#ifdef LIBPNG
+#include <png.h>
+
 int _png_load(const char* file, int* width, int* height){
     FILE *f;
     int is_png, bit_depth, color_type, row_bytes;
@@ -113,6 +111,116 @@ int _png_load(const char* file, int* width, int* height){
     fclose( f );
     return texture;
 }
+#else
+#include <spng.h>
+#include <stdio.h>
+#include <inttypes.h>
+
+int _png_load(const char* file, int* pwidth, int* pheight){
+	int r = 0;
+	FILE *png;
+	char *pngbuf = nullptr;
+	spng_ctx *ctx = nullptr;
+	unsigned char *out = nullptr;
+
+	png = fopen(file, "rb");
+	if (png == nullptr){
+		std::cerr << "could not to open file " << file << std::endl;
+		return 0;
+	}
+
+	fseek(png, 0, SEEK_END);
+	long siz_pngbuf = ftell(png);
+	rewind(png);
+	if(siz_pngbuf < 1) {
+		std::cerr << "could not to read file " << file << std::endl;
+		return 0;
+	}
+	pngbuf = new char[siz_pngbuf];
+	if(fread(pngbuf, siz_pngbuf, 1, png) != 1){
+		std::cerr << "fread() failed" << std::endl;
+		return 0;
+	}
+	ctx = spng_ctx_new(0);
+	if (ctx == nullptr){
+		std::cerr << "spng_ctx_new() failed" << std::endl;
+		return 0;
+	}
+	r = spng_set_crc_action(ctx, SPNG_CRC_USE, SPNG_CRC_USE);
+	if (r){
+		std::cerr << "spng_set_crc_action() error: " << spng_strerror(r) << std::endl;
+		return 0;
+	}
+	r = spng_set_png_buffer(ctx, pngbuf, siz_pngbuf);
+	if (r){
+		std::cerr << "spng_set_png_buffer() error: " << spng_strerror(r) << std::endl;
+		return 0;
+	}
+
+	spng_ihdr ihdr;
+	r = spng_get_ihdr(ctx, &ihdr);
+	if (r){
+		std::cerr << "spng_get_ihdr() error: " << spng_strerror(r) << std::endl;
+		return 0;
+	}
+
+	char *clr_type_str;
+	if(ihdr.color_type == SPNG_COLOR_TYPE_GRAYSCALE)
+		clr_type_str = "grayscale";
+	else if(ihdr.color_type == SPNG_COLOR_TYPE_TRUECOLOR)
+		clr_type_str = "truecolor";
+	else if(ihdr.color_type == SPNG_COLOR_TYPE_INDEXED)
+		clr_type_str = "indexed color";
+	else if(ihdr.color_type == SPNG_COLOR_TYPE_GRAYSCALE_ALPHA)
+		clr_type_str = "grayscale with alpha";
+	else
+		clr_type_str = "truecolor with alpha";
+
+	size_t out_size;
+	r = spng_decoded_image_size(ctx, SPNG_FMT_RGBA8, &out_size);
+	if (r){
+		std::cerr << "spng_decoded_image_size() error: " << spng_strerror(r) << std::endl;
+		return 0;
+	}
+	out = new unsigned char[out_size];
+	r = spng_decode_image(ctx, out, out_size, SPNG_FMT_RGBA8, 0);
+	if (r){
+		std::cerr << "spng_decode_image() error: " << spng_strerror(r) << std::endl;
+		return 0;
+	}
+
+	unsigned char* flipped = new unsigned char[out_size];
+
+	for (size_t i = 0; i < ihdr.height; i+=1){
+		size_t rowsize = ihdr.width*4;
+		for (size_t j = 0; j < rowsize; j++){
+			flipped[(ihdr.height-i-1)*rowsize+j] = out[i*rowsize+j];
+		}
+	}
+	delete[] out;
+
+    unsigned int texture;
+    int alpha = GL_RGBA;
+
+    glGenTextures(1, &texture);
+    glBindTexture(GL_TEXTURE_2D, texture);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, ihdr.width, ihdr.height, 0,
+        alpha, GL_UNSIGNED_BYTE, (GLvoid *) flipped);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glBindTexture(GL_TEXTURE_2D, 0);
+
+    pwidth[0] = ihdr.width;
+    pheight[0] = ihdr.height;
+
+	spng_ctx_free(ctx);
+	delete[] pngbuf;
+
+    return texture;
+}
+
+#endif
 
 Texture* load_texture(std::string filename){
 	int width, height;
diff --git a/src/loaders/png_loading.h b/src/loaders/png_loading.h
index a8f502df..e4dc3847 100644
--- a/src/loaders/png_loading.h
+++ b/src/loaders/png_loading.h
@@ -1,10 +1,3 @@
-/*
- * png_loading.h
- *
- *  Created on: Feb 10, 2020
- *      Author: MihailRis
- */
-
 #ifndef LOADERS_PNG_LOADING_H_
 #define LOADERS_PNG_LOADING_H_
 
diff --git a/src/physics/Hitbox.cpp b/src/physics/Hitbox.cpp
new file mode 100644
index 00000000..ea9d1a8e
--- /dev/null
+++ b/src/physics/Hitbox.cpp
@@ -0,0 +1,4 @@
+#include "Hitbox.h"
+
+Hitbox::Hitbox(vec3 position, vec3 halfsize) : position(position), halfsize(halfsize), velocity(0.0f,0.0f,0.0f) {
+}
diff --git a/src/physics/Hitbox.h b/src/physics/Hitbox.h
new file mode 100644
index 00000000..2e86ee4b
--- /dev/null
+++ b/src/physics/Hitbox.h
@@ -0,0 +1,20 @@
+#ifndef PHYSICS_HITBOX_H_
+#define PHYSICS_HITBOX_H_
+
+#include <glm/glm.hpp>
+#include <glm/ext.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+
+using namespace glm;
+
+class Hitbox {
+public:
+	vec3 position;
+	vec3 halfsize;
+	vec3 velocity;
+	bool grounded = false;
+
+	Hitbox(vec3 position, vec3 halfsize);
+};
+
+#endif /* PHYSICS_HITBOX_H_ */
diff --git a/src/physics/PhysicsSolver.cpp b/src/physics/PhysicsSolver.cpp
new file mode 100644
index 00000000..240a3aa5
--- /dev/null
+++ b/src/physics/PhysicsSolver.cpp
@@ -0,0 +1,148 @@
+#include "PhysicsSolver.h"
+#include "Hitbox.h"
+#include "../voxels/Chunks.h"
+
+#include <iostream>
+
+#define E 0.01
+
+PhysicsSolver::PhysicsSolver(vec3 gravity) : gravity(gravity) {
+}
+
+void PhysicsSolver::step(Chunks* chunks, Hitbox* hitbox, float delta, unsigned substeps, bool shifting) {
+	for (unsigned i = 0; i < substeps; i++){
+		float dt = delta / (float)substeps;
+		vec3& pos = hitbox->position;
+		vec3& half = hitbox->halfsize;
+		vec3& vel = hitbox->velocity;
+		vel.x += gravity.x*dt;
+		vel.y += gravity.y*dt;
+		vel.z += gravity.z*dt;
+
+		float px = pos.x;
+		float pz = pos.z;
+
+		if (vel.x < 0.0){
+			for (int y = floor(pos.y-half.y+E); y <= floor(pos.y+half.y-E); y++){
+				for (int z = floor(pos.z-half.z+E); z <= floor(pos.z+half.z-E); z++){
+					int x = floor(pos.x-half.x-E);
+					if (chunks->isObstacle(x,y,z)){
+						vel.x *= 0.0;
+						pos.x = x + 1 + half.x + E;
+						break;
+					}
+				}
+			}
+		}
+		if (vel.x > 0.0){
+			for (int y = floor(pos.y-half.y+E); y <= floor(pos.y+half.y-E); y++){
+				for (int z = floor(pos.z-half.z+E); z <= floor(pos.z+half.z-E); z++){
+					int x = floor(pos.x+half.x+E);
+					if (chunks->isObstacle(x,y,z)){
+						vel.x *= 0.0;
+						pos.x = x - half.x - E;
+						break;
+					}
+				}
+			}
+		}
+
+		if (vel.z < 0.0){
+			for (int y = floor(pos.y-half.y+E); y <= floor(pos.y+half.y-E); y++){
+				for (int x = floor(pos.x-half.x+E); x <= floor(pos.x+half.x-E); x++){
+					int z = floor(pos.z-half.z-E);
+					if (chunks->isObstacle(x,y,z)){
+						vel.z *= 0.0;
+						pos.z = z + 1 + half.z + E;
+						break;
+					}
+				}
+			}
+		}
+
+		if (vel.z > 0.0){
+			for (int y = floor(pos.y-half.y+E); y <= floor(pos.y+half.y-E); y++){
+				for (int x = floor(pos.x-half.x+E); x <= floor(pos.x+half.x-E); x++){
+					int z = floor(pos.z+half.z+E);
+					if (chunks->isObstacle(x,y,z)){
+						vel.z *= 0.0;
+						pos.z = z - half.z - E;
+						break;
+					}
+				}
+			}
+		}
+
+		hitbox->grounded = false;
+		if (vel.y < 0.0){
+			for (int x = floor(pos.x-half.x+E); x <= floor(pos.x+half.x-E); x++){
+				for (int z = floor(pos.z-half.z+E); z <= floor(pos.z+half.z-E); z++){
+					int y = floor(pos.y-half.y-E);
+					if (chunks->isObstacle(x,y,z)){
+						vel.y *= 0.0;
+						pos.y = y + 1 + half.y;
+						int f = 18.0;
+						vel.x *= max(0.0, 1.0 - dt * f);
+						vel.z *= max(0.0, 1.0 - dt * f);
+						hitbox->grounded = true;
+						break;
+					}
+				}
+			}
+		}
+		if (vel.y > 0.0){
+			for (int x = floor(pos.x-half.x+E); x <= floor(pos.x+half.x-E); x++){
+				for (int z = floor(pos.z-half.z+E); z <= floor(pos.z+half.z-E); z++){
+					int y = floor(pos.y+half.y+E);
+					if (chunks->isObstacle(x,y,z)){
+						vel.y *= 0.0;
+						pos.y = y - half.y - E;
+						break;
+					}
+				}
+			}
+		}
+
+		pos.x += vel.x * dt;
+		pos.y += vel.y * dt;
+		pos.z += vel.z * dt;
+
+		if (shifting && hitbox->grounded){
+			int y = floor(pos.y-half.y-E);
+
+			hitbox->grounded = false;
+			for (int x = floor(px-half.x+E); x <= floor(px+half.x-E); x++){
+				for (int z = floor(pos.z-half.z+E); z <= floor(pos.z+half.z-E); z++){
+					if (chunks->isObstacle(x,y,z)){
+						hitbox->grounded = true;
+						break;
+					}
+				}
+			}
+			if (!hitbox->grounded)
+				pos.z = pz;
+			hitbox->grounded = false;
+
+			for (int x = floor(pos.x-half.x+E); x <= floor(pos.x+half.x-E); x++){
+				for (int z = floor(pz-half.z+E); z <= floor(pz+half.z-E); z++){
+					if (chunks->isObstacle(x,y,z)){
+						hitbox->grounded = true;
+						break;
+					}
+				}
+			}
+			if (!hitbox->grounded)
+				pos.x = px;
+
+			hitbox->grounded = true;
+		}
+	}
+}
+
+bool PhysicsSolver::isBlockInside(int x, int y, int z, Hitbox* hitbox) {
+	vec3& pos = hitbox->position;
+	vec3& half = hitbox->halfsize;
+	return x >= floor(pos.x-half.x) && x <= floor(pos.x+half.x) &&
+			z >= floor(pos.z-half.z) && z <= floor(pos.z+half.z) &&
+			y >= floor(pos.y-half.y) && y <= floor(pos.y+half.y);
+}
diff --git a/src/physics/PhysicsSolver.h b/src/physics/PhysicsSolver.h
new file mode 100644
index 00000000..467d78d7
--- /dev/null
+++ b/src/physics/PhysicsSolver.h
@@ -0,0 +1,21 @@
+#ifndef PHYSICS_PHYSICSSOLVER_H_
+#define PHYSICS_PHYSICSSOLVER_H_
+
+#include <glm/glm.hpp>
+#include <glm/ext.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+
+using namespace glm;
+
+class Hitbox;
+class Chunks;
+
+class PhysicsSolver {
+	vec3 gravity;
+public:
+	PhysicsSolver(vec3 gravity);
+	void step(Chunks* chunks, Hitbox* hitbox, float delta, unsigned substeps, bool shifting);
+	bool isBlockInside(int x, int y, int z, Hitbox* hitbox);
+};
+
+#endif /* PHYSICS_PHYSICSSOLVER_H_ */
diff --git a/src/voxel_engine.cpp b/src/voxel_engine.cpp
index a3fe8c45..f8e9a4b0 100644
--- a/src/voxel_engine.cpp
+++ b/src/voxel_engine.cpp
@@ -32,6 +32,8 @@ using namespace glm;
 #include "lighting/LightSolver.h"
 #include "lighting/Lightmap.h"
 #include "lighting/Lighting.h"
+#include "physics/Hitbox.h"
+#include "physics/PhysicsSolver.h"
 
 int WIDTH = 1280;
 int HEIGHT = 720;
@@ -49,90 +51,166 @@ int attrs[] = {
 		2,  0 //null terminator
 };
 
-int main() {
-	Window::initialize(WIDTH, HEIGHT, "Window 2.0");
-	Events::initialize();
+Mesh *crosshair;
+Shader *shader, *linesShader, *crosshairShader;
+Texture *texture;
+LineBatch *lineBatch;
 
-	Shader* shader = load_shader("res/main.glslv", "res/main.glslf");
+Chunks* chunks;
+WorldFiles* wfile;
+
+// All in-game definitions (blocks, items, etc..)
+void setup_definitions() {
+	// AIR
+	Block* block = new Block(0,0);
+	block->drawGroup = 1;
+	block->lightPassing = true;
+	block->obstacle = false;
+	Block::blocks[block->id] = block;
+
+	// STONE
+	block = new Block(1,2);
+	Block::blocks[block->id] = block;
+
+	// GRASS
+	block = new Block(2,4);
+	block->textureFaces[2] = 2;
+	block->textureFaces[3] = 1;
+	Block::blocks[block->id] = block;
+
+	// LAMP
+	block = new Block(3,3);
+	block->emission[0] = 15;
+	block->emission[1] = 14;
+	block->emission[2] = 13;
+	Block::blocks[block->id] = block;
+
+	// GLASS
+	block = new Block(4,5);
+	block->drawGroup = 2;
+	block->lightPassing = true;
+	Block::blocks[block->id] = block;
+
+	// PLANKS
+	block = new Block(5,6);
+	Block::blocks[block->id] = block;
+}
+
+// Shaders, textures, renderers
+int initialize_assets() {
+	shader = load_shader("res/main.glslv", "res/main.glslf");
 	if (shader == nullptr){
 		std::cerr << "failed to load shader" << std::endl;
 		Window::terminate();
 		return 1;
 	}
 
-	Shader* crosshairShader = load_shader("res/crosshair.glslv", "res/crosshair.glslf");
+	crosshairShader = load_shader("res/crosshair.glslv", "res/crosshair.glslf");
 	if (crosshairShader == nullptr){
 		std::cerr << "failed to load crosshair shader" << std::endl;
 		Window::terminate();
 		return 1;
 	}
 
-	Shader* linesShader = load_shader("res/lines.glslv", "res/lines.glslf");
+	linesShader = load_shader("res/lines.glslv", "res/lines.glslf");
 	if (linesShader == nullptr){
 		std::cerr << "failed to load lines shader" << std::endl;
 		Window::terminate();
 		return 1;
 	}
 
-	Texture* texture = load_texture("res/block.png");
+	texture = load_texture("res/block.png");
 	if (texture == nullptr){
 		std::cerr << "failed to load texture" << std::endl;
 		delete shader;
 		Window::terminate();
 		return 1;
 	}
+	return 0;
+}
 
-	{
-		// AIR
-		Block* block = new Block(0,0);
-		block->drawGroup = 1;
-		block->lightPassing = true;
-		Block::blocks[block->id] = block;
+void draw_world(Camera* camera){
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-		// STONE
-		block = new Block(1,2);
-		Block::blocks[block->id] = block;
-
-		// GRASS
-		block = new Block(2,4);
-		block->textureFaces[2] = 2;
-		block->textureFaces[3] = 1;
-		Block::blocks[block->id] = block;
-
-		// LAMP
-		block = new Block(3,3);
-		block->emission[0] = 10;
-		block->emission[1] = 0;
-		block->emission[2] = 0;
-		Block::blocks[block->id] = block;
-
-		// GLASS
-		block = new Block(4,5);
-		block->drawGroup = 2;
-		block->lightPassing = true;
-		Block::blocks[block->id] = block;
-
-		// PLANKS
-		block = new Block(5,6);
-		Block::blocks[block->id] = block;
+	// Draw VAO
+	shader->use();
+	shader->uniformMatrix("u_projview", camera->getProjection()*camera->getView());
+	shader->uniform1f("u_gamma", 1.6f);
+	shader->uniform3f("u_skyLightColor", 0.1*2,0.15*2,0.2*2);
+	texture->bind();
+	mat4 model(1.0f);
+	for (size_t i = 0; i < chunks->volume; i++){
+		Chunk* chunk = chunks->chunks[i];
+		if (chunk == nullptr)
+			continue;
+		Mesh* mesh = chunks->meshes[i];
+		if (mesh == nullptr)
+			continue;
+		model = glm::translate(mat4(1.0f), vec3(chunk->x*CHUNK_W+0.5f, chunk->y*CHUNK_H+0.5f, chunk->z*CHUNK_D+0.5f));
+		shader->uniformMatrix("u_model", model);
+		mesh->draw(GL_TRIANGLES);
 	}
 
-	WorldFiles wfile = WorldFiles("world/", 24*1024*1024);
-	Chunks* chunks = new Chunks(16*4,1,16*4, 0,0,0);
-	VoxelRenderer renderer(1024*1024*8);
-	LineBatch* lineBatch = new LineBatch(4096);
+	crosshairShader->use();
+	crosshair->draw(GL_LINES);
+
+	linesShader->use();
+	linesShader->uniformMatrix("u_projview", camera->getProjection()*camera->getView());
+	glLineWidth(2.0f);
+	lineBatch->render();
+}
+
+// Deleting GL objects like shaders, textures
+void finalize_assets(){
+	delete shader;
+	delete texture;
+	delete crosshair;
+	delete crosshairShader;
+	delete linesShader;
+	delete lineBatch;
+}
+
+// Save all world data to files
+void write_world(){
+	for (unsigned int i = 0; i < chunks->volume; i++){
+		Chunk* chunk = chunks->chunks[i];
+		if (chunk == nullptr)
+			continue;
+		wfile->put((const char*)chunk->voxels, chunk->x, chunk->z);
+	}
+
+	wfile->write();
+}
+
+// Deleting world data from memory
+void close_world(){
+	delete chunks;
+	delete wfile;
+}
+
+int main() {
+	setup_definitions();
+
+	Window::initialize(WIDTH, HEIGHT, "Window 2.0");
+	Events::initialize();
+
+	int result = initialize_assets();
+	if (result){
+		Window::terminate();
+		return result;
+	}
+
+	wfile = new WorldFiles("world/", REGION_VOL * (CHUNK_VOL * 2 + 8));
+	chunks = new Chunks(32,1,32, 0,0,0);
+	VoxelRenderer renderer(1024*1024);
+	lineBatch = new LineBatch(4096);
+	PhysicsSolver physics(vec3(0,-16.0f,0));
 
 	Lighting::initialize(chunks);
 
-	glClearColor(0.0f,0.0f,0.0f,1);
-
-	glEnable(GL_DEPTH_TEST);
-	glEnable(GL_CULL_FACE);
-	glEnable(GL_BLEND);
-	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-
-	Mesh* crosshair = new Mesh(vertices, 4, attrs);
+	crosshair = new Mesh(vertices, 4, attrs);
 	Camera* camera = new Camera(vec3(32,32,32), radians(90.0f));
+	Hitbox* hitbox = new Hitbox(vec3(32,32,32), vec3(0.2f,0.9f,0.2f));
 
 	float lastTime = glfwGetTime();
 	float delta = 0.0f;
@@ -140,13 +218,15 @@ int main() {
 	float camX = 0.0f;
 	float camY = 0.0f;
 
-	float speed = 15;
+	float playerSpeed = 4.0f;
 
 	int choosenBlock = 1;
+	long frame = 0;
 
-	glfwSwapInterval(0);
+	glfwSwapInterval(1);
 
 	while (!Window::isShouldClose()){
+		frame++;
 		float currentTime = glfwGetTime();
 		delta = currentTime - lastTime;
 		lastTime = currentTime;
@@ -164,22 +244,58 @@ int main() {
 			}
 		}
 
-		if (Events::pressed(GLFW_KEY_W)){
-			camera->position += camera->front * delta * speed;
+		// Controls
+		bool sprint = Events::pressed(GLFW_KEY_LEFT_CONTROL);
+		bool shift = Events::pressed(GLFW_KEY_LEFT_SHIFT) && hitbox->grounded && !sprint;
+
+		float speed = playerSpeed;
+		int substeps = (int)(delta * 1000);
+		substeps = (substeps <= 0 ? 1 : (substeps > 100 ? 100 : substeps));
+		physics.step(chunks, hitbox, delta, substeps, shift);
+		camera->position.x = hitbox->position.x;
+		camera->position.y = hitbox->position.y + 0.5f;
+		camera->position.z = hitbox->position.z;
+
+		float dt = min(1.0f, delta * 16);
+		if (shift){
+			speed *= 0.25f;
+			camera->position.y -= 0.2f;
+			camera->zoom = 0.9f * dt + camera->zoom * (1.0f - dt);
+		} else if (sprint){
+			speed *= 1.5f;
+			camera->zoom = 1.1f * dt + camera->zoom * (1.0f - dt);
+		} else {
+			camera->zoom = dt + camera->zoom * (1.0f - dt);
 		}
-		if (Events::pressed(GLFW_KEY_S)){
-			camera->position -= camera->front * delta * speed;
-		}
-		if (Events::pressed(GLFW_KEY_D)){
-			camera->position += camera->right * delta * speed;
-		}
-		if (Events::pressed(GLFW_KEY_A)){
-			camera->position -= camera->right * delta * speed;
+		if (Events::pressed(GLFW_KEY_SPACE) && hitbox->grounded){
+			hitbox->velocity.y = 6.0f;
 		}
 
-		chunks->setCenter(camera->position.x,0,camera->position.z);
+		vec3 dir(0,0,0);
+		if (Events::pressed(GLFW_KEY_W)){
+			dir.x += camera->dir.x;
+			dir.z += camera->dir.z;
+		}
+		if (Events::pressed(GLFW_KEY_S)){
+			dir.x -= camera->dir.x;
+			dir.z -= camera->dir.z;
+		}
+		if (Events::pressed(GLFW_KEY_D)){
+			dir.x += camera->right.x;
+			dir.z += camera->right.z;
+		}
+		if (Events::pressed(GLFW_KEY_A)){
+			dir.x -= camera->right.x;
+			dir.z -= camera->right.z;
+		}
+		if (length(dir) > 0.0f)
+			dir = normalize(dir);
+		hitbox->velocity.x = dir.x * speed;
+		hitbox->velocity.z = dir.z * speed;
+
+		chunks->setCenter(wfile, camera->position.x,0,camera->position.z);
 		chunks->_buildMeshes(&renderer);
-		chunks->loadVisible(&wfile);
+		chunks->loadVisible(wfile);
 
 		if (Events::_cursor_locked){
 			camY += -Events::deltaY / Window::height * 2;
@@ -215,62 +331,24 @@ int main() {
 					int x = (int)(iend.x)+(int)(norm.x);
 					int y = (int)(iend.y)+(int)(norm.y);
 					int z = (int)(iend.z)+(int)(norm.z);
-					chunks->set(x, y, z, choosenBlock);
-					Lighting::onBlockSet(x,y,z, choosenBlock);
+					if (!physics.isBlockInside(x,y,z, hitbox)){
+						chunks->set(x, y, z, choosenBlock);
+						Lighting::onBlockSet(x,y,z, choosenBlock);
+					}
 				}
 			}
 		}
-
-		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
-		// Draw VAO
-		shader->use();
-		shader->uniformMatrix("projview", camera->getProjection()*camera->getView());
-		texture->bind();
-		mat4 model(1.0f);
-		for (size_t i = 0; i < chunks->volume; i++){
-			Chunk* chunk = chunks->chunks[i];
-			if (chunk == nullptr)
-				continue;
-			Mesh* mesh = chunks->meshes[i];
-			if (mesh == nullptr)
-				continue;
-			model = glm::translate(mat4(1.0f), vec3(chunk->x*CHUNK_W+0.5f, chunk->y*CHUNK_H+0.5f, chunk->z*CHUNK_D+0.5f));
-			shader->uniformMatrix("model", model);
-			mesh->draw(GL_TRIANGLES);
-		}
-
-		crosshairShader->use();
-		crosshair->draw(GL_LINES);
-
-		linesShader->use();
-		linesShader->uniformMatrix("projview", camera->getProjection()*camera->getView());
-		glLineWidth(2.0f);
-		lineBatch->render();
+		draw_world(camera);
 
 		Window::swapBuffers();
 		Events::pullEvents();
 	}
 
+	write_world();
+	close_world();
+
 	Lighting::finalize();
-
-	for (unsigned int i = 0; i < chunks->volume; i++){
-		Chunk* chunk = chunks->chunks[i];
-		if (chunk == nullptr)
-			continue;
-		wfile.put((const char*)chunk->voxels, chunk->x, chunk->z);
-	}
-
-	wfile.write();
-
-	delete shader;
-	delete texture;
-	delete chunks;
-	delete crosshair;
-	delete crosshairShader;
-	delete linesShader;
-	delete lineBatch;
-
+	finalize_assets();
 	Window::terminate();
 	return 0;
 }
diff --git a/src/voxels/Block.h b/src/voxels/Block.h
index ce4ec452..09d4108f 100644
--- a/src/voxels/Block.h
+++ b/src/voxels/Block.h
@@ -11,6 +11,7 @@ public:
 	unsigned char emission[3];
 	unsigned char drawGroup = 0;
 	bool lightPassing = false;
+	bool obstacle = true;
 
 	Block(unsigned int id, int texture);
 };
diff --git a/src/voxels/Chunk.h b/src/voxels/Chunk.h
index 8cb3815c..68467e66 100644
--- a/src/voxels/Chunk.h
+++ b/src/voxels/Chunk.h
@@ -2,7 +2,7 @@
 #define VOXELS_CHUNK_H_
 
 #define CHUNK_W 16
-#define CHUNK_H 128
+#define CHUNK_H 64
 #define CHUNK_D 16
 #define CHUNK_VOL (CHUNK_W * CHUNK_H * CHUNK_D)
 
diff --git a/src/voxels/Chunks.cpp b/src/voxels/Chunks.cpp
index e0ccbc8d..b6eea117 100644
--- a/src/voxels/Chunks.cpp
+++ b/src/voxels/Chunks.cpp
@@ -1,6 +1,7 @@
 #include "Chunks.h"
 #include "Chunk.h"
 #include "voxel.h"
+#include "Block.h"
 #include "WorldGenerator.h"
 #include "../lighting/Lightmap.h"
 #include "../files/WorldFiles.h"
@@ -129,6 +130,13 @@ voxel* Chunks::get(int x, int y, int z){
 	return &chunk->voxels[(ly * CHUNK_D + lz) * CHUNK_W + lx];
 }
 
+bool Chunks::isObstacle(int x, int y, int z){
+	voxel* v = get(x,y,z);
+	if (v == nullptr)
+		return true; // void - is obstacle
+	return Block::blocks[v->id]->obstacle;
+}
+
 unsigned char Chunks::getLight(int x, int y, int z, int channel){
 	x -= ox * CHUNK_W;
 	y -= oy * CHUNK_H;
@@ -292,7 +300,7 @@ voxel* Chunks::rayCast(vec3 a, vec3 dir, float maxDist, vec3& end, vec3& norm, v
 	return nullptr;
 }
 
-void Chunks::setCenter(int x, int y, int z) {
+void Chunks::setCenter(WorldFiles* worldFiles, int x, int y, int z) {
 	int cx = x / CHUNK_W;
 	int cy = y / CHUNK_H;
 	int cz = z / CHUNK_D;
@@ -306,7 +314,7 @@ void Chunks::setCenter(int x, int y, int z) {
 	cy -= h/2;
 	cz -= d/2;
 	if (cx != 0 || cy != 0 || cz != 0)
-		translate(cx,cy,cz);
+		translate(worldFiles, cx,cy,cz);
 }
 
 bool Chunks::loadVisible(WorldFiles* worldFiles){
@@ -349,7 +357,7 @@ bool Chunks::loadVisible(WorldFiles* worldFiles){
 	return true;
 }
 
-void Chunks::translate(int dx, int dy, int dz){
+void Chunks::translate(WorldFiles* worldFiles, int dx, int dy, int dz){
 	for (unsigned int i = 0; i < volume; i++){
 		chunksSecond[i] = nullptr;
 		meshesSecond[i] = nullptr;
@@ -365,6 +373,7 @@ void Chunks::translate(int dx, int dy, int dz){
 					continue;
 				Mesh* mesh = meshes[(y * d + z) * w + x];
 				if (nx < 0 || ny < 0 || nz < 0 || nx >= w || ny >= h || nz >= d){
+					worldFiles->put((const char*)chunk->voxels, chunk->x, chunk->z);
 					delete chunk;
 					delete mesh;
 					continue;
diff --git a/src/voxels/Chunks.h b/src/voxels/Chunks.h
index b70e4baf..2c5641b8 100644
--- a/src/voxels/Chunks.h
+++ b/src/voxels/Chunks.h
@@ -33,8 +33,10 @@ public:
 	void set(int x, int y, int z, int id);
 	voxel* rayCast(vec3 start, vec3 dir, float maxLength, vec3& end, vec3& norm, vec3& iend);
 
-	void setCenter(int x, int y, int z);
-	void translate(int x, int y, int z);
+	bool isObstacle(int x, int y, int z);
+
+	void setCenter(WorldFiles* worldFiles, int x, int y, int z);
+	void translate(WorldFiles* worldFiles, int x, int y, int z);
 
 	bool loadVisible(WorldFiles* worldFiles);
 	bool _buildMeshes(VoxelRenderer* renderer);
diff --git a/src/window/Camera.cpp b/src/window/Camera.cpp
index 05bc0361..4dfcc2b7 100644
--- a/src/window/Camera.cpp
+++ b/src/window/Camera.cpp
@@ -10,7 +10,7 @@
 
 #include <glm/ext.hpp>
 
-Camera::Camera(vec3 position, float fov) : position(position), fov(fov), rotation(1.0f) {
+Camera::Camera(vec3 position, float fov) : position(position), fov(fov), zoom(1.0f), rotation(1.0f) {
 	updateVectors();
 }
 
@@ -18,6 +18,13 @@ void Camera::updateVectors(){
 	front = vec3(rotation * vec4(0,0,-1,1));
 	right = vec3(rotation * vec4(1,0,0,1));
 	up = vec3(rotation * vec4(0,1,0,1));
+	dir = vec3(rotation * vec4(0,0,-1,1));
+	dir.y = 0;
+	float len = length(dir);
+	if (len > 0.0f){
+		dir.x /= len;
+		dir.z /= len;
+	}
 }
 
 void Camera::rotate(float x, float y, float z){
@@ -30,7 +37,7 @@ void Camera::rotate(float x, float y, float z){
 
 mat4 Camera::getProjection(){
 	float aspect = (float)Window::width / (float)Window::height;
-	return glm::perspective(fov, aspect, 0.1f, 1500.0f);
+	return glm::perspective(fov*zoom, aspect, 0.05f, 1500.0f);
 }
 
 mat4 Camera::getView(){
diff --git a/src/window/Camera.h b/src/window/Camera.h
index c42a0a93..91648adb 100644
--- a/src/window/Camera.h
+++ b/src/window/Camera.h
@@ -17,9 +17,11 @@ public:
 	vec3 front;
 	vec3 up;
 	vec3 right;
+	vec3 dir;
 
 	vec3 position;
 	float fov;
+	float zoom;
 	mat4 rotation;
 	Camera(vec3 position, float fov);
 
diff --git a/src/window/Window.cpp b/src/window/Window.cpp
index c3cf644f..ef6d48d8 100644
--- a/src/window/Window.cpp
+++ b/src/window/Window.cpp
@@ -30,6 +30,12 @@ int Window::initialize(int width, int height, const char* title){
 	}
 	glViewport(0,0, width, height);
 
+	glClearColor(0.0f,0.0f,0.0f,1);
+	glEnable(GL_DEPTH_TEST);
+	glEnable(GL_CULL_FACE);
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
 	Window::width = width;
 	Window::height = height;
 	return 0;