From 6d56ff2bb18d9b08e61da6bf9b6d1f8ed0a59d2e Mon Sep 17 00:00:00 2001
From: Shariq Shah <bluerriq@gmail.com>
Date: Sat, 11 Jul 2015 17:54:34 +0500
Subject: [PATCH] Ported Shader and Geometry code from Project Abstraction.
 Minor additions to array and string utils

---
 src/array.c        |   6 +-
 src/array.h        |  10 +-
 src/game.c         |  39 +++---
 src/geometry.c     | 254 +++++++++++++++++++++++++++++++++++++
 src/geometry.h     |  10 ++
 src/input.c        |  11 +-
 src/input.h        |   3 +-
 src/linmath.h      | 104 +++++++--------
 src/log.c          |  10 ++
 src/log.h          |   1 +
 src/renderer.c     |  40 ++++++
 src/renderer.h     |   1 +
 src/shader.c       | 309 +++++++++++++++++++++++++++++++++++++++++++++
 src/shader.h       |  20 +++
 src/string_utils.c |   7 -
 15 files changed, 731 insertions(+), 94 deletions(-)
 create mode 100644 src/geometry.c
 create mode 100644 src/geometry.h
 create mode 100644 src/shader.c
 create mode 100644 src/shader.h

diff --git a/src/array.c b/src/array.c
index 1705556..c01c58e 100644
--- a/src/array.c
+++ b/src/array.c
@@ -7,13 +7,13 @@
 
 static bool array_reallocate(Array* array);
 
-Array* array_new_(size_t object_size)
+Array* array_new_(size_t object_size, int capacity)
 {
 	Array* newArray = malloc(sizeof(Array));
 
 	newArray->object_size = object_size;
 	newArray->length = 0;
-	newArray->capacity = ARRAY_MIN_CAPACITY;
+	newArray->capacity = capacity == 0 ? ARRAY_MIN_CAPACITY : capacity;
 	newArray->data = malloc(newArray->object_size * newArray->capacity);
 
 	return newArray;
@@ -60,7 +60,7 @@ void* array_add(Array* array)
 
 void array_reset(Array* array, unsigned int length)
 {
-	free(array->data);
+	if(array->data) free(array->data);
 	array->length = length;
 	array->capacity = length < ARRAY_MIN_CAPACITY ? ARRAY_MIN_CAPACITY : length;
 	array->data = malloc(array->object_size * array->capacity);
diff --git a/src/array.h b/src/array.h
index cd30f4e..fcbcf93 100644
--- a/src/array.h
+++ b/src/array.h
@@ -12,19 +12,25 @@ typedef struct
 	size_t       object_size;   // size per element
 } Array;
 
-Array* array_new_(size_t object_size);
-#define array_new(type) array_new_(sizeof(type)); // Use this for array creation
+Array* array_new_(size_t object_size, int capacity);
+#define array_new(type) array_new_(sizeof(type), 0); // Use this for array creation
+#define array_new_cap(type, capacity) array_new_(sizeof(type), capacity); // Use this for array with specific capacity
 void array_free(Array* array);
 
 // All the macros with _val return by value while the function returns pointer
 void* array_get(Array* array, unsigned int index);
 #define array_get_val(array, type, index) (*((type*) array_get(array, index)))
+#define array_get_last_val(array, type) array_get_val(array, type, array->length - 1)
+#define array_get_raw(array, type) (type*) array->data
 
 void* array_top(Array* array);
 #define array_top_val(array, type) (*((type*) array_top(array)))
 
 void* array_add(Array* array);
 #define array_add_val(array, type) (*((type*) array_add(array)))
+#define array_push(array, value, type) \
+	type* new_val = array_add(array);  \
+	*new_val      = value;
 
 void array_reset(Array* array, unsigned int length); // Resize to length objects whose data is unspecified
 #define array_clear(array) array_reset(array, 0)
diff --git a/src/game.c b/src/game.c
index 7856b85..2b557b7 100644
--- a/src/game.c
+++ b/src/game.c
@@ -1,10 +1,13 @@
-#include "game.h"
+#include <stdlib.h>
 #include "GLFW/glfw3.h"
+#include "game.h"
 
 #include "window_system.h"
 #include "input.h"
 #include "renderer.h"
 #include "log.h"
+#include "file_io.h"
+#include "shader.h"
 
 void run(void);
 void update(void);
@@ -13,16 +16,22 @@ void render(void);
 void game_init(void)
 {
 	GLFWwindow* window = window_get_active();
+	/* Init systems */
 	input_init(window);
 	renderer_init(window);
-	int keys[2] = {GLFW_KEY_W, GLFW_KEY_UP};
-	int keys2[2] = {GLFW_KEY_S, GLFW_KEY_DOWN};
-	int keys3[1] = {GLFW_KEY_J};
-	int keys4[1] = {GLFW_KEY_K};
+	io_file_initialize("/mnt/Dev/Projects/Symmetry/assets/");/* TODO: Implement proper way of getting binary directory */
+	shader_initialize();
+	
+	int keys[2] = {'W', GLFW_KEY_UP};
+	int keys2[2] = {'S', GLFW_KEY_DOWN};
+	int keys3[1] = {'J'};
+	int keys4[1] = {'K'};
 	input_map_create("MoveUp", keys, 2);
 	input_map_create("MoveDown", keys2, 2);
 	input_map_create("Test", keys3, 1);
 	input_map_create("Test2", keys4, 1);
+
+	int shader = shader_create("phong.vert", "phong.frag");	
 	run();
 }
 
@@ -39,24 +48,6 @@ void run(void)
 
 void update(void)
 {
-	if(input_map_state_get("MoveUp", GLFW_RELEASE))
-		log_message("MoveUp pressed!");
-
-	if(input_map_state_get("MoveDown", GLFW_RELEASE))
-		log_message("MoveDown pressed!");
-
-	if(input_map_state_get("Test", GLFW_RELEASE))
-		log_message("Test released");
-
-	if(input_map_state_get("Test2", GLFW_RELEASE))
-	{
-		input_map_name_set("Test2", "NewTest");
-		log_message("Test2 released!");
-	}
-
-	if(input_map_state_get("NewTest", GLFW_RELEASE))
-		log_message("NewTest released");
-
 	input_update();
 }
 
@@ -69,4 +60,6 @@ void game_cleanup(void)
 {
 	input_cleanup();
 	renderer_cleanup();
+	io_file_cleanup();
+	shader_cleanup();
 }
diff --git a/src/geometry.c b/src/geometry.c
new file mode 100644
index 0000000..f2874b3
--- /dev/null
+++ b/src/geometry.c
@@ -0,0 +1,254 @@
+#include "geometry.h"
+#include "array.h"
+#include "num_types.h"
+#include "linmath.h"
+#include "string_utils.h"
+#include "file_io.h"
+#include "log.h"
+#include "renderer.h"
+
+#include "GL/glew.h"
+#include "GLFW/glfw3.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+typedef struct 
+{
+	char*  filename;
+	bool   draw_indexed;
+	Array* vertices;
+	Array* vertex_colors;
+	Array* normals;
+	Array* uvs;
+	Array* indices;
+	uint   vao;
+	uint   vertex_vbo;
+	uint   uv_vbo;
+	uint   normal_vbo;
+	uint   color_vbo;
+	uint   index_vbo;
+	uint   ref_count;
+	/* BoundingBox               boundingBox; */
+	/* BoundingSphere            boundingSphere; */
+} Geometry;
+
+/* Data */
+static Array* geometry_list;
+static Array* empty_indices;
+
+/* Function definitions */
+bool load_from_file(Geometry* geometry, const char* filename);
+void create_vao(Geometry* geometry);
+
+void geom_initialize(void)
+{
+	geometry_list = array_new(Geometry);
+	empty_indices = array_new(int);
+}
+
+int geom_find(const char* filename)
+{
+	int index = -1;
+	for(int i = 0; i < (int)geometry_list->length; i++)
+	{
+		Geometry* geometry = array_get(geometry_list, i);
+		if(strcmp(geometry->filename, filename) == 0)
+		{
+			index = i;
+			break;
+		}
+	}
+	return index;
+}
+
+int geom_create(const char* name)
+{
+	// check if exists
+	int index = geom_find(name);
+	if(index == -1)
+	{
+		/* add new geometry object or overwrite existing one */
+		Geometry* new_geo = NULL;
+		int index = -1;
+		if(empty_indices->length != 0)
+		{
+			index = array_get_last_val(empty_indices, int);
+			array_pop(empty_indices);
+			new_geo = array_get(geometry_list, index);
+		}
+		else
+		{
+			new_geo = array_add(geometry_list);
+			index = geometry_list->length - 1;
+		}
+		assert(new_geo);
+		
+		
+		if(load_from_file(new_geo, name))
+		{
+			create_vao(new_geo);
+			//generateBoundingBox(index);
+		}
+		else
+		{
+			/* TODO: Some error here, find it and fix it */
+			array_pop(geometry_list);
+			index = -1;
+		}
+	}
+	else
+	{
+		Geometry* raw_geom_array = array_get_raw(geometry_list, Geometry);
+		raw_geom_array[index].ref_count++;
+	}
+	return index;
+}
+
+void geom_remove(int index)
+{
+	if(index >= 0 && index < (int)geometry_list->length)
+	{
+		Geometry* geometry = array_get(geometry_list, index);
+		array_free(geometry->indices);
+		array_free(geometry->vertices);
+		array_free(geometry->uvs);
+		array_free(geometry->normals);
+		array_free(geometry->vertex_colors);
+		free(geometry->filename);
+		array_push(empty_indices, index, int);
+	}
+}
+
+void geom_cleanup(void)
+{
+	for(uint i = 0; i < geometry_list->length; i++)
+		geom_remove(i);
+	
+	array_free(geometry_list);
+	array_free(empty_indices);
+}
+
+bool load_from_file(Geometry* geometry, const char* filename)
+{
+	assert(filename);
+	bool success = true;
+	char* full_path = str_new("models/");
+	full_path = str_concat(full_path, filename);
+			
+	FILE* file = io_file_open(full_path, "rb");
+	free(full_path);
+	if(file)
+	{				
+		const uint32 INDEX_SIZE = sizeof(uint32);
+		const uint32 VEC3_SIZE  = sizeof(vec3);
+		const uint32 VEC2_SIZE  = sizeof(vec2);
+		uint32 header[4];
+		size_t bytes_read = 0;
+		if((bytes_read = fread(header, INDEX_SIZE, 4, file)) <= 0)
+		{
+			log_error("geometry:load_from_file", "Read failed");
+			success = false;
+		}
+		else
+		{
+			uint32 indices_count  = header[0];
+			uint32 vertices_count = header[1];
+			uint32 normals_count  = header[2];
+			uint32 uvs_count      = header[3];
+			// Indices
+			geometry->indices = array_new_cap(uint, indices_count);
+			fread(geometry->indices->data, INDEX_SIZE, indices_count, file);
+			// Vertices
+			geometry->vertices = array_new_cap(uint, vertices_count);
+			fread(geometry->vertices->data, VEC3_SIZE, vertices_count, file);
+			// Normals
+			geometry->normals = array_new_cap(uint, normals_count);
+			fread(&geometry->normals->data, VEC3_SIZE, normals_count, file);
+			// Uvs
+			geometry->uvs = array_new_cap(uint, uvs_count);
+			fread(&geometry->uvs->data, VEC2_SIZE, uvs_count, file);
+		}
+		fclose(file);
+		geometry->filename = str_new(filename);
+		geometry->draw_indexed = true;
+		geometry->ref_count++;
+	}
+	else
+	{
+		success = false;
+	}
+		
+	return success;
+}
+
+void create_vao(Geometry* geometry)
+{
+	// TODO : Add support for different model formats and interleaving VBO
+	assert(geometry);
+	glGenVertexArrays(1, &geometry->vao);
+	glBindVertexArray(geometry->vao);
+
+	glGenBuffers(1, &geometry->vertex_vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, geometry->vertex_vbo);
+	glBufferData(GL_ARRAY_BUFFER,
+				 geometry->vertices->length * sizeof(vec3),
+				 geometry->vertices->data,
+				 GL_STATIC_DRAW);
+	renderer_check_glerror("Geometry::create_vbo::vertex");
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
+
+	if(geometry->normals->length > 0)
+	{
+		glGenBuffers(1, &geometry->normal_vbo);
+		glBindBuffer(GL_ARRAY_BUFFER, geometry->normal_vbo);
+		glBufferData(GL_ARRAY_BUFFER,
+					 geometry->normals->length * sizeof(vec3),
+					 geometry->normals->data,
+					 GL_STATIC_DRAW);
+		renderer_check_glerror("Geometry::create_vbo::normal");
+		glEnableVertexAttribArray(1);
+		glVertexAttribPointer(1, 3, GL_FLOAT, GL_TRUE, 0, 0);
+	}
+
+	if(geometry->uvs->length > 0)
+	{
+		glGenBuffers(1, &geometry->uv_vbo);
+		glBindBuffer(GL_ARRAY_BUFFER, geometry->uv_vbo);
+		glBufferData(GL_ARRAY_BUFFER,
+					 geometry->uvs->length * sizeof(vec2),
+					 geometry->uvs->data,
+					 GL_STATIC_DRAW);
+		renderer_check_glerror("Geometry::create_vbo::uv");
+		glEnableVertexAttribArray(2);
+		glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, 0);
+	}
+
+	if(geometry->vertex_colors->length > 0)
+	{
+		glGenBuffers(1, &geometry->color_vbo);
+		glBindBuffer(GL_ARRAY_BUFFER, geometry->color_vbo);
+		glBufferData(GL_ARRAY_BUFFER,
+					 geometry->vertex_colors->length * sizeof(vec3),
+					 geometry->vertex_colors->data,
+					 GL_STATIC_DRAW);
+		renderer_check_glerror("Geometry::create_vbo::color");
+		glEnableVertexAttribArray(3);
+		glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, 0, 0);
+	}
+
+	if(geometry->indices->length > 0)
+	{
+		glGenBuffers(1, &geometry->index_vbo);
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, geometry->index_vbo);
+		glBufferData(GL_ELEMENT_ARRAY_BUFFER,
+					 geometry->indices->length * sizeof(GLuint),
+					 geometry->indices->data,
+					 GL_STATIC_DRAW);
+		geometry->draw_indexed = true;
+	}
+	glBindVertexArray(0);
+}
diff --git a/src/geometry.h b/src/geometry.h
new file mode 100644
index 0000000..2f91238
--- /dev/null
+++ b/src/geometry.h
@@ -0,0 +1,10 @@
+#ifndef geometry_H
+#define geometry_H
+
+void geom_initialize(void);
+int  geom_ceate(const char* name);
+int  geom_find(const char* filename);
+void geom_remove(int index);
+void geom_cleanup(void);
+
+#endif
diff --git a/src/input.c b/src/input.c
index 08b1d6c..b90bbbb 100644
--- a/src/input.c
+++ b/src/input.c
@@ -22,7 +22,6 @@ void input_init(GLFWwindow* window)
 	glfwSetMouseButtonCallback(window, input_on_mousebutton);
 	glfwSetKeyCallback(window, input_on_key);
 	glfwSetCursorPosCallback(window, input_on_cursor_move);
-	glfwSetInputMode(window, GLFW_STICKY_KEYS, 1);
 
 	input_map_list = array_new(Input_Map);
 }
@@ -42,7 +41,7 @@ static void input_on_cursor_move(GLFWwindow* window, double xpos, double ypos)
 	
 }
 
-void input_get_cursor_pos(double* xpos, double* ypos)
+void input_cursor_pos_get(double* xpos, double* ypos)
 {
 	assert(xpos && ypos);
 	GLFWwindow* window = window_get_active();
@@ -68,7 +67,9 @@ static void input_on_key(GLFWwindow* window, int key, int scancode, int action,
 
 static void input_on_mousebutton(GLFWwindow* window, int button, int action, int mods)
 {
-	
+	/* Probably add 'mouse maps', same as input maps for keyvboard but with buttons
+	   Do we even need that?
+	*/
 }
 
 void input_cursor_mode_set(Cursor_Mode mode)
@@ -98,7 +99,7 @@ bool input_map_state_get(const char* map_name, int state)
 	return state == current_state ? true : false;
 }
 
-bool inputkey_state_get(int key, int state_type)
+bool input_key_state_get(int key, int state_type)
 {
 	GLFWwindow* window = window_get_active();
 	int current_state  = glfwGetKey(window, key);
@@ -137,7 +138,7 @@ void input_update(void)
 	}
 }
 
-bool input_map_remvove(const char* name)
+bool input_map_remove(const char* name)
 {
 	assert(name);
 	bool success = false;
diff --git a/src/input.h b/src/input.h
index 9becdc8..812cdae 100644
--- a/src/input.h
+++ b/src/input.h
@@ -13,7 +13,6 @@ typedef enum
 	
 } Cursor_Mode;
 
-
 typedef struct
 {
 	Array*      keys;
@@ -31,7 +30,7 @@ void input_cursor_mode_set(Cursor_Mode mode);
 void input_update(void);
 bool input_map_state_get(const char* map_name, int state);
 void input_map_create(const char* name, int* keys, size_t num_keys);
-bool input_map_remvove(const char* name);
+bool input_map_remove(const char* name);
 bool input_map_keys_set(const char* name, int* keys, int num_keys);
 bool input_map_name_set(const char* name, const char* new_name);
 
diff --git a/src/linmath.h b/src/linmath.h
index 3216cd8..2a5c833 100644
--- a/src/linmath.h
+++ b/src/linmath.h
@@ -76,9 +76,9 @@ static inline void vec4_reflect(vec4 r, vec4 v, vec4 n)
 		r[i] = v[i] - p*n[i];
 }
 
-typedef vec4 mat4x4[4];
+typedef vec4 mat4[4];
 
-static inline void mat4x4_identity(mat4x4 M)
+static inline void mat4_identity(mat4 M)
 {
 	int i, j;
 	for(i=0; i<4; ++i)
@@ -86,7 +86,7 @@ static inline void mat4x4_identity(mat4x4 M)
 			M[i][j] = i==j ? 1.f : 0.f;
 }
 
-static inline void mat4x4_dup(mat4x4 M, mat4x4 N)
+static inline void mat4_dup(mat4 M, mat4 N)
 {
 	int i, j;
 	for(i=0; i<4; ++i)
@@ -94,21 +94,21 @@ static inline void mat4x4_dup(mat4x4 M, mat4x4 N)
 			M[i][j] = N[i][j];
 }
 
-static inline void mat4x4_row(vec4 r, mat4x4 M, int i)
+static inline void mat4_row(vec4 r, mat4 M, int i)
 {
 	int k;
 	for(k=0; k<4; ++k)
 		r[k] = M[k][i];
 }
 
-static inline void mat4x4_col(vec4 r, mat4x4 M, int i)
+static inline void mat4_col(vec4 r, mat4 M, int i)
 {
 	int k;
 	for(k=0; k<4; ++k)
 		r[k] = M[i][k];
 }
 
-static inline void mat4x4_transpose(mat4x4 M, mat4x4 N)
+static inline void mat4_transpose(mat4 M, mat4 N)
 {
 	int i, j;
 	for(j=0; j<4; ++j)
@@ -116,28 +116,28 @@ static inline void mat4x4_transpose(mat4x4 M, mat4x4 N)
 			M[i][j] = N[j][i];
 }
 
-static inline void mat4x4_add(mat4x4 M, mat4x4 a, mat4x4 b)
+static inline void mat4_add(mat4 M, mat4 a, mat4 b)
 {
 	int i;
 	for(i=0; i<4; ++i)
 		vec4_add(M[i], a[i], b[i]);
 }
 
-static inline void mat4x4_sub(mat4x4 M, mat4x4 a, mat4x4 b)
+static inline void mat4_sub(mat4 M, mat4 a, mat4 b)
 {
 	int i;
 	for(i=0; i<4; ++i)
 		vec4_sub(M[i], a[i], b[i]);
 }
 
-static inline void mat4x4_scale(mat4x4 M, mat4x4 a, float k)
+static inline void mat4_scale(mat4 M, mat4 a, float k)
 {
 	int i;
 	for(i=0; i<4; ++i)
 		vec4_scale(M[i], a[i], k);
 }
 
-static inline void mat4x4_scale_aniso(mat4x4 M, mat4x4 a, float x, float y, float z)
+static inline void mat4_scale_aniso(mat4 M, mat4 a, float x, float y, float z)
 {
 	int i;
 	vec4_scale(M[0], a[0], x);
@@ -148,19 +148,19 @@ static inline void mat4x4_scale_aniso(mat4x4 M, mat4x4 a, float x, float y, floa
 	}
 }
 
-static inline void mat4x4_mul(mat4x4 M, mat4x4 a, mat4x4 b)
+static inline void mat4_mul(mat4 M, mat4 a, mat4 b)
 {
-	mat4x4 temp;
+	mat4 temp;
 	int k, r, c;
 	for(c=0; c<4; ++c) for(r=0; r<4; ++r) {
 			temp[c][r] = 0.f;
 			for(k=0; k<4; ++k)
 				temp[c][r] += a[k][r] * b[c][k];
 		}
-	mat4x4_dup(M, temp);
+	mat4_dup(M, temp);
 }
 
-static inline void mat4x4_mul_vec4(vec4 r, mat4x4 M, vec4 v)
+static inline void mat4_mul_vec4(vec4 r, mat4 M, vec4 v)
 {
 	int i, j;
 	for(j=0; j<4; ++j) {
@@ -170,101 +170,101 @@ static inline void mat4x4_mul_vec4(vec4 r, mat4x4 M, vec4 v)
 	}
 }
 
-static inline void mat4x4_translate(mat4x4 T, float x, float y, float z)
+static inline void mat4_translate(mat4 T, float x, float y, float z)
 {
-	mat4x4_identity(T);
+	mat4_identity(T);
 	T[3][0] = x;
 	T[3][1] = y;
 	T[3][2] = z;
 }
 
-static inline void mat4x4_translate_in_place(mat4x4 M, float x, float y, float z)
+static inline void mat4_translate_in_place(mat4 M, float x, float y, float z)
 {
 	vec4 t = {x, y, z, 0};
 	vec4 r;
 	int i;
 	for (i = 0; i < 4; ++i) {
-		mat4x4_row(r, M, i);
+		mat4_row(r, M, i);
 		M[3][i] += vec4_mul_inner(r, t);
 	}
 }
 
-static inline void mat4x4_from_vec3_mul_outer(mat4x4 M, vec3 a, vec3 b)
+static inline void mat4_from_vec3_mul_outer(mat4 M, vec3 a, vec3 b)
 {
 	int i, j;
 	for(i=0; i<4; ++i) for(j=0; j<4; ++j)
 						   M[i][j] = i<3 && j<3 ? a[i] * b[j] : 0.f;
 }
 
-static inline void mat4x4_rotate(mat4x4 R, mat4x4 M, float x, float y, float z, float angle)
+static inline void mat4_rotate(mat4 R, mat4 M, float x, float y, float z, float angle)
 {
 	float s = sinf(angle);
 	float c = cosf(angle);
 	vec3 u = {x, y, z};
 	if(vec3_len(u) > 1e-4) {
 		vec3_norm(u, u);
-		mat4x4 T;
-		mat4x4_from_vec3_mul_outer(T, u, u);
-		mat4x4 S = {
+		mat4 T;
+		mat4_from_vec3_mul_outer(T, u, u);
+		mat4 S = {
 			{ 0, u[2], -u[1], 0},
 			{-u[2], 0, u[0], 0},
 			{ u[1], -u[0], 0, 0},
 			{ 0, 0, 0, 0}
 		};
-		mat4x4_scale(S, S, s);
-		mat4x4 C;
-		mat4x4_identity(C);
-		mat4x4_sub(C, C, T);
-		mat4x4_scale(C, C, c);
-		mat4x4_add(T, T, C);
-		mat4x4_add(T, T, S);
+		mat4_scale(S, S, s);
+		mat4 C;
+		mat4_identity(C);
+		mat4_sub(C, C, T);
+		mat4_scale(C, C, c);
+		mat4_add(T, T, C);
+		mat4_add(T, T, S);
 		T[3][3] = 1.;
-		mat4x4_mul(R, M, T);
+		mat4_mul(R, M, T);
 	} else {
-		mat4x4_dup(R, M);
+		mat4_dup(R, M);
 	}
 }
 
-static inline void mat4x4_rotate_X(mat4x4 Q, mat4x4 M, float angle)
+static inline void mat4_rotate_X(mat4 Q, mat4 M, float angle)
 {
 	float s = sinf(angle);
 	float c = cosf(angle);
-	mat4x4 R = {
+	mat4 R = {
 		{1.f, 0.f, 0.f, 0.f},
 		{0.f, c, s, 0.f},
 		{0.f, -s, c, 0.f},
 		{0.f, 0.f, 0.f, 1.f}
 	};
-	mat4x4_mul(Q, M, R);
+	mat4_mul(Q, M, R);
 }
 
-static inline void mat4x4_rotate_Y(mat4x4 Q, mat4x4 M, float angle)
+static inline void mat4_rotate_Y(mat4 Q, mat4 M, float angle)
 {
 	float s = sinf(angle);
 	float c = cosf(angle);
-	mat4x4 R = {
+	mat4 R = {
 		{ c, 0.f, s, 0.f},
 		{ 0.f, 1.f, 0.f, 0.f},
 		{ -s, 0.f, c, 0.f},
 		{ 0.f, 0.f, 0.f, 1.f}
 	};
-	mat4x4_mul(Q, M, R);
+	mat4_mul(Q, M, R);
 }
 
-static inline void mat4x4_rotate_Z(mat4x4 Q, mat4x4 M, float angle)
+static inline void mat4_rotate_Z(mat4 Q, mat4 M, float angle)
 {
 	float s = sinf(angle);
 	float c = cosf(angle);
-	mat4x4 R = {
+	mat4 R = {
 		{ c, s, 0.f, 0.f},
 		{ -s, c, 0.f, 0.f},
 		{ 0.f, 0.f, 1.f, 0.f},
 		{ 0.f, 0.f, 0.f, 1.f}
 	};
-	mat4x4_mul(Q, M, R);
+	mat4_mul(Q, M, R);
 }
 
-static inline void mat4x4_invert(mat4x4 T, mat4x4 M)
+static inline void mat4_invert(mat4 T, mat4 M)
 {
 	float s[6];
 	float c[6];
@@ -300,9 +300,9 @@ static inline void mat4x4_invert(mat4x4 T, mat4x4 M)
 	T[3][3] = ( M[2][0] * s[3] - M[2][1] * s[1] + M[2][2] * s[0]) * idet;
 }
 
-static inline void mat4x4_orthonormalize(mat4x4 R, mat4x4 M)
+static inline void mat4_orthonormalize(mat4 R, mat4 M)
 {
-	mat4x4_dup(R, M);
+	mat4_dup(R, M);
 	float s = 1.;
 	vec3 h;
 	vec3_norm(R[2], R[2]);
@@ -320,7 +320,7 @@ static inline void mat4x4_orthonormalize(mat4x4 R, mat4x4 M)
 	vec3_norm(R[0], R[0]);
 }
 
-static inline void mat4x4_frustum(mat4x4 M, float l, float r, float b, float t, float n, float f)
+static inline void mat4_frustum(mat4 M, float l, float r, float b, float t, float n, float f)
 {
 	M[0][0] = 2.f*n/(r-l);
 	M[0][1] = M[0][2] = M[0][3] = 0.f;
@@ -334,7 +334,7 @@ static inline void mat4x4_frustum(mat4x4 M, float l, float r, float b, float t,
 	M[3][0] = M[3][1] = M[3][3] = 0.f;
 }
 
-static inline void mat4x4_ortho(mat4x4 M, float l, float r, float b, float t, float n, float f)
+static inline void mat4_ortho(mat4 M, float l, float r, float b, float t, float n, float f)
 {
 	M[0][0] = 2.f/(r-l);
 	M[0][1] = M[0][2] = M[0][3] = 0.f;
@@ -348,7 +348,7 @@ static inline void mat4x4_ortho(mat4x4 M, float l, float r, float b, float t, fl
 	M[3][3] = 1.f;
 }
 
-static inline void mat4x4_perspective(mat4x4 m, float y_fov, float aspect, float n, float f)
+static inline void mat4_perspective(mat4 m, float y_fov, float aspect, float n, float f)
 {
 /* NOTE: Degrees are an unhandy unit to work with.
  * linmath.h uses radians for everything! */
@@ -371,7 +371,7 @@ static inline void mat4x4_perspective(mat4x4 m, float y_fov, float aspect, float
 	m[3][3] = 0.f;
 }
 
-static inline void mat4x4_look_at(mat4x4 m, vec3 eye, vec3 center, vec3 up)
+static inline void mat4_look_at(mat4 m, vec3 eye, vec3 center, vec3 up)
 {
 /* Adapted from Android's OpenGL Matrix.java. */
 /* See the OpenGL GLUT documentation for gluLookAt for a description */
@@ -402,7 +402,7 @@ static inline void mat4x4_look_at(mat4x4 m, vec3 eye, vec3 center, vec3 up)
 	m[3][1] = 0.f;
 	m[3][2] = 0.f;
 	m[3][3] = 1.f;
-	mat4x4_translate_in_place(m, -eye[0], -eye[1], -eye[2]);
+	mat4_translate_in_place(m, -eye[0], -eye[1], -eye[2]);
 }
 
 typedef float quat[4];
@@ -482,7 +482,7 @@ static inline void quat_mul_vec3(vec3 r, quat q, vec3 v)
 	quat_mul(r, q, r);
 }
 
-static inline void mat4x4_from_quat(mat4x4 M, quat q)
+static inline void mat4_from_quat(mat4 M, quat q)
 {
 	float a = q[3];
 	float b = q[0];
@@ -508,7 +508,7 @@ static inline void mat4x4_from_quat(mat4x4 M, quat q)
 	M[3][3] = 1.f;
 }
 
-static inline void mat4x4o_mul_quat(mat4x4 R, mat4x4 M, quat q)
+static inline void mat4o_mul_quat(mat4 R, mat4 M, quat q)
 {
 /* XXX: The way this is written only works for othogonal matrices. */
 /* TODO: Take care of non-orthogonal case. */
@@ -519,7 +519,7 @@ static inline void mat4x4o_mul_quat(mat4x4 R, mat4x4 M, quat q)
 	R[3][3] = 1.f;
 }
 
-static inline void quat_from_mat4x4(quat q, mat4x4 M)
+static inline void quat_from_mat4(quat q, mat4 M)
 {
 	float r=0.f;
 	int i;
diff --git a/src/log.c b/src/log.c
index 012bb21..9a755f6 100644
--- a/src/log.c
+++ b/src/log.c
@@ -13,6 +13,16 @@ void log_message(const char* message, ...)
 	printf("\n");
 }
 
+void log_warning(const char* message, ...)
+{
+	printf("WRN : ");
+	va_list list;
+	va_start(list, message);
+	vprintf(message, list);
+	va_end(list);
+	printf("\n");
+}
+
 void log_error(const char* context, const char* error, ...)
 {
 	printf("ERR (%s) : ", context);
diff --git a/src/log.h b/src/log.h
index d9f939a..50d55b9 100644
--- a/src/log.h
+++ b/src/log.h
@@ -2,6 +2,7 @@
 #define log_H
 
 void log_message(const char* message, ...);
+void log_warning(const char* message, ...);
 void log_error(const char* context, const char* error, ...);
 
 #endif
diff --git a/src/renderer.c b/src/renderer.c
index 93d7dc0..8b696de 100644
--- a/src/renderer.c
+++ b/src/renderer.c
@@ -1,6 +1,8 @@
 #include "renderer.h"
 #include "GLFW/glfw3.h"
 
+#include "log.h"
+
 void on_framebuffer_size_change(GLFWwindow* window, int width, int height);
 
 void renderer_init(GLFWwindow* window)
@@ -28,3 +30,41 @@ void renderer_set_clearcolor(float red, float green, float blue, float alpha)
 {
 	glClearColor(red, green, blue, alpha);
 }
+
+void renderer_check_glerror(const char* context)
+{
+	GLenum error = glGetError();
+	const char* errorString = "No Error";
+	switch(error)
+	{
+	case GL_INVALID_OPERATION:
+		errorString = "Invalid Operation";
+		break;
+	case GL_NO_ERROR:
+		errorString = "No Error";
+		break;
+	case GL_INVALID_ENUM:
+		errorString = "Invalid ENUM";
+		break;
+	case GL_INVALID_VALUE:
+		errorString = "Invalid Value";
+		break;
+	case GL_INVALID_FRAMEBUFFER_OPERATION:
+		errorString = "Invalid FrameBuffer Operation";
+		break;
+	case GL_OUT_OF_MEMORY:
+		errorString = "Out of Memory";
+		break;
+	case GL_STACK_UNDERFLOW:
+		errorString = "Stack Underflow";
+		break;
+	case GL_STACK_OVERFLOW:
+		errorString = "Stack Overflow";
+		break;
+	}
+
+	if(error != GL_NO_ERROR)
+	{
+		log_error(context, errorString);
+	}
+}
diff --git a/src/renderer.h b/src/renderer.h
index cf47f4c..97c4000 100644
--- a/src/renderer.h
+++ b/src/renderer.h
@@ -7,5 +7,6 @@ void renderer_init(GLFWwindow* window);
 void renderer_draw(void);
 void renderer_cleanup(void);
 void renderer_set_clearcolor(float r, float g, float b, float a);
+void renderer_check_glerror(const char* context);
 
 #endif
diff --git a/src/shader.c b/src/shader.c
new file mode 100644
index 0000000..3363b38
--- /dev/null
+++ b/src/shader.c
@@ -0,0 +1,309 @@
+#include "shader.h"
+#include "file_io.h"
+#include "array.h"
+#include "num_types.h"
+#include "string_utils.h"
+#include "log.h"
+#include "renderer.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "GL/glew.h"
+#include "GLFW/glfw3.h"
+
+typedef struct
+{
+	unsigned int vertex_shader;
+	unsigned int fragment_shader;
+	unsigned int program;
+	
+} Shader_Object;
+
+
+// Constants for locations of attributes inside all shaders
+const int POSITION_LOC = 0;
+const int NORMAL_LOC   = 1;
+const int UV_LOC       = 2;
+const int COLOR_LOC    = 3;
+
+static Array* shader_list;
+static Array* empty_indices;
+
+void debug_print_shader(const char* shaderText)
+{
+	size_t len = strlen(shaderText);
+	int line_count = 1;
+	printf("%d. ", line_count);
+	for(uint i = 0; i < len; i++)
+	{
+		if(shaderText[i] != '\n')
+			printf("%c", shaderText[i]);
+		else
+			printf("\n%d. ", ++line_count);
+	}
+	printf("\n END_DEBUG_PRINT\n\n");
+}
+
+char* run_preprocessor(char* shader_text)
+{
+	char* include_loc = strstr(shader_text, "//include");
+	if(include_loc)
+	{
+		char* line_end = strchr(include_loc, '\n');
+		int line_size  = line_end - include_loc;
+		char* inc_line = malloc((sizeof(char) * line_size) + 1);
+		strncpy(inc_line, include_loc, line_size);
+		inc_line[line_size] = '\0';
+
+		char* filename = strtok(inc_line, " ");
+		while(filename)
+		{
+			filename = strtok(NULL, " ");
+			if(filename)
+			{
+				char* path = str_new("shaders/");
+				path = str_concat(path, filename);
+				char* file = io_file_read(path);
+				char* shader_copy = str_new(shader_text);
+				char* temp = realloc(shader_text, (strlen(shader_text) + strlen(file) + 2));
+				if(temp)
+				{
+					shader_text = temp;
+					strcpy(shader_text, file);
+					strcat(shader_text, shader_copy);
+				}
+				else
+				{
+					log_warning("Realloc failed in Shader::run_preprocessor");
+				}
+
+				free(path);
+				free(shader_copy);
+				free(file);
+			}
+		}
+		free(inc_line);
+	}
+	return shader_text;
+}
+
+void shader_initialize(void)
+{
+	shader_list = array_new(Shader_Object);
+	empty_indices = array_new(int);
+}
+	
+int shader_create(const char* vert_shader_name, const char* frag_shader_name)
+{
+	char* vs_path = str_new("shaders/");
+	vs_path = str_concat(vs_path, vert_shader_name);
+	char* fs_path = str_new("shaders/");
+	fs_path = str_concat(fs_path, frag_shader_name);
+		
+	GLuint vert_shader = glCreateShader(GL_VERTEX_SHADER);
+	GLuint frag_shader = glCreateShader(GL_FRAGMENT_SHADER);
+
+	char* vert_source = io_file_read(vs_path);
+	char* frag_source = io_file_read(fs_path);
+
+	assert(vert_source != NULL);
+	assert(frag_source != NULL);
+
+	vert_source = run_preprocessor(vert_source);		
+	frag_source = run_preprocessor(frag_source);
+		
+	GLint v_size = (GLint)strlen(vert_source);
+	GLint f_size = (GLint)strlen(frag_source);
+		
+	const char* vert_sourcePtr = vert_source;
+	const char* frag_sourcePtr = frag_source;
+		
+	const GLint* vert_size = &v_size;
+	const GLint* frag_size = &f_size;
+		
+	glShaderSource(vert_shader, 1, &vert_sourcePtr, vert_size);
+	glShaderSource(frag_shader, 1, &frag_sourcePtr, frag_size);
+
+	glCompileShader(vert_shader);
+	glCompileShader(frag_shader);
+		
+	GLint is_vert_compiled = 0;
+	GLint is_frag_compiled = 0;
+	glGetShaderiv(vert_shader, GL_COMPILE_STATUS, &is_vert_compiled);
+	glGetShaderiv(frag_shader, GL_COMPILE_STATUS, &is_frag_compiled);
+
+	if(!is_vert_compiled)
+	{
+		GLint log_size = 0;
+		glGetShaderiv(vert_shader, GL_INFO_LOG_LENGTH, &log_size);
+		char* message = (char *)malloc(sizeof(char) * log_size);
+		glGetShaderInfoLog(vert_shader, log_size, NULL, message);
+
+		log_error("shader:create", "COMPILING VS %s : %s", vert_shader_name, message);
+		debug_print_shader(vert_source);
+		free(message);
+	}
+
+	if(!is_frag_compiled)
+	{
+		GLint log_size = 0;
+		glGetShaderiv(frag_shader, GL_INFO_LOG_LENGTH, &log_size);
+		char* message = (char *)malloc(sizeof(char) * log_size);
+		glGetShaderInfoLog(frag_shader, log_size, NULL, message);
+
+		log_error("shader:create", "COMPILING FS %s : %s", frag_shader_name, message);
+		debug_print_shader(frag_source);
+		free(message);
+	}
+
+	free(vert_source);
+	free(frag_source);
+		
+	if(!is_vert_compiled || !is_frag_compiled)
+	{
+		glDeleteShader(vert_shader);
+		glDeleteShader(frag_shader);
+		return -1;
+	}
+
+	GLuint program = glCreateProgram();
+	glAttachShader(program, vert_shader);
+	glAttachShader(program, frag_shader);
+
+	// Bind attribute locations
+	glBindAttribLocation(program, POSITION_LOC, "vPosition");
+	glBindAttribLocation(program, NORMAL_LOC,   "vNormal");
+	glBindAttribLocation(program, UV_LOC,       "vUV");
+	glBindAttribLocation(program, COLOR_LOC,    "vColor");
+	renderer_check_glerror("shader:create");
+	glLinkProgram(program);
+
+	GLint is_linked = 0;
+	glGetProgramiv(program, GL_LINK_STATUS, &is_linked);
+	if(!is_linked)
+	{
+		GLint log_size = 0;
+		glGetProgramiv(program, GL_LINK_STATUS, &log_size);
+		char* message = (char *)malloc(sizeof(char) * log_size);
+		glGetProgramInfoLog(program, log_size, NULL, message);
+		log_error("shader:create", "LINK SHADER : %s", message);
+		free(message);
+
+		glDeleteProgram(program);
+		glDeleteShader(vert_shader);
+		glDeleteShader(frag_shader);
+			
+		return -1;
+	}
+
+	/* add new object or overwrite existing one */
+	Shader_Object* new_object = NULL;
+	int index = -1;
+	if(empty_indices->length != 0)
+	{
+		index = array_get_last_val(empty_indices, int);
+		array_pop(empty_indices);
+		new_object = array_get(shader_list, index);
+	}
+	else
+	{
+		new_object = array_add(shader_list);
+		index = shader_list->length - 1;
+	}
+	assert(new_object);
+	new_object->vertex_shader   = vert_shader;
+	new_object->fragment_shader = frag_shader;
+	new_object->program         = program;
+	
+	log_message("%s, %s compiled into shader program", vert_shader_name, frag_shader_name);
+	free(vs_path);
+	free(fs_path);
+	
+	return index;
+}
+
+void shader_bind(const int shader_index)
+{
+	Shader_Object* shader_object = array_get(shader_list, shader_index);
+	glUseProgram(shader_object->program);
+}
+
+void shader_unbind(void)
+{
+	glUseProgram(0);
+}
+
+int get_uniform_location(const int shader_index, const char* name)
+{
+	Shader_Object shader_object = array_get_val(shader_list, Shader_Object, shader_index);
+	GLint handle = glGetUniformLocation(shader_object.program, name);
+
+	if(handle == -1)
+		log_error("shader:get_uniform_location", "Invalid uniform %s", name);
+
+	return handle;
+}
+
+void set_uniform_int(const int shader_index, const char* name, const int value)
+{
+	GLint location = get_uniform_location(shader_index, name);
+	if(location >= 0)
+		glUniform1i(location, value);
+}
+	
+void set_uniform_float(const int shader_index, const char* name, const float value)
+{
+	GLint location = get_uniform_location(shader_index, name);
+	if(location >= 0)
+		glUniform1f(location, value);
+}
+	
+void set_uniform_vec2(const int shader_index,  const char* name, const vec2 value)
+{
+	GLint location = get_uniform_location(shader_index, name);
+	if(location >= 0)
+		glUniform2fv(location, 1, value);
+}
+	
+void set_uniform_vec3(const int shader_index,  const char* name, const vec3 value)
+{
+	GLint location = get_uniform_location(shader_index, name);
+	if(location >= 0)
+		glUniform3fv(location, 1, value);
+}
+	
+void set_uniform_vec4(const int shader_index,  const char* name, const vec4 value)
+{
+	GLint location = get_uniform_location(shader_index, name);
+	if(location >= 0)
+		glUniform4fv(location, 1, value);
+}
+	
+void setUniformMat4(const int shader_index,  const char* name, const mat4 value)
+{
+	GLint location = get_uniform_location(shader_index, name);
+	if(location >= 0)
+		glUniformMatrix4fv(location, 1, GL_FALSE, *value);
+}
+
+void shader_remove(const int shader_index)
+{
+	Shader_Object* shader_object = array_get(shader_list, shader_index);
+	glDeleteProgram(shader_object->program);
+	glDeleteShader(shader_object->vertex_shader);
+	glDeleteShader(shader_object->fragment_shader);
+	shader_object->fragment_shader = shader_object->vertex_shader = shader_object->program = -1;
+	array_push(empty_indices, shader_index, int);
+}
+	
+void shader_cleanup(void)
+{
+	for(int i = 0; i < (int)shader_list->length; i++)
+		shader_remove(i);
+
+	array_free(shader_list);
+	array_free(empty_indices);
+}
diff --git a/src/shader.h b/src/shader.h
new file mode 100644
index 0000000..3b17cbe
--- /dev/null
+++ b/src/shader.h
@@ -0,0 +1,20 @@
+#ifndef shader_H
+#define shader_H
+
+#include "linmath.h"
+    
+int  shader_create(const char* vert_shader_name, const char* frag_shader_name);
+void shader_initialize(void);
+void shader_bind(const int shader_index);
+void shader_remove(const int shader_index);
+void shader_unbind(void);
+void shader_set_uniform_int(const int shaderIndex, const char* name, const int value);
+void shader_set_uniform_float(const int shaderIndex, const char* name, const float value);
+void shader_set_uniform_vec2(const int shaderIndex,  const char* name, const vec2 value);
+void shader_set_uniform_vec3(const int shaderIndex,  const char* name, const vec3 value);
+void shader_set_uniform_vec4(const int shaderIndex,  const char* name, const vec4 value);
+void shader_set_uniform_mat4(const int shaderIndex,  const char* name, const mat4 value);
+void shader_cleanup(void);
+int  shader_uniform_location_get(const int shader_index, const char* name);
+
+#endif
diff --git a/src/string_utils.c b/src/string_utils.c
index 41ee8ae..128070a 100644
--- a/src/string_utils.c
+++ b/src/string_utils.c
@@ -98,10 +98,3 @@ char* str_replace(char* string, const char* pattern, const char* replacement)
 		return NULL;
 	}
 }
-
-
-
-
-
-
-