diff --git a/include/glkos.h.gch b/include/glkos.h.gch
new file mode 100644
index 0000000..c2e3e27
Binary files /dev/null and b/include/glkos.h.gch differ
diff --git a/samples/depth_funcs_alpha_testing/Makefile b/samples/depth_funcs_alpha_testing/Makefile
new file mode 100644
index 0000000..2c09473
--- /dev/null
+++ b/samples/depth_funcs_alpha_testing/Makefile
@@ -0,0 +1,30 @@
+TARGET = depth_funcs.elf
+OBJS = main.o gl_png.o
+KOS_CFLAGS += -std=c99
+
+all: rm-elf $(TARGET)
+
+include $(KOS_BASE)/Makefile.rules
+
+clean:
+	-rm -f $(TARGET) $(OBJS) romdisk.*
+
+rm-elf:
+	-rm -f $(TARGET) romdisk.*
+
+$(TARGET): $(OBJS) romdisk.o
+	$(KOS_CC) $(KOS_CFLAGS) $(KOS_LDFLAGS) -o $(TARGET) $(KOS_START) \
+		$(OBJS) romdisk.o $(OBJEXTRA) -lm -lkosutils $(KOS_LIBS)
+
+romdisk.img:
+	$(KOS_GENROMFS) -f romdisk.img -d romdisk -v
+
+romdisk.o: romdisk.img
+	$(KOS_BASE)/utils/bin2o/bin2o romdisk.img romdisk romdisk.o
+
+run: $(TARGET)
+	$(KOS_LOADER) $(TARGET)
+
+dist:
+	rm -f $(OBJS) romdisk.o romdisk.img
+	$(KOS_STRIP) $(TARGET)
diff --git a/samples/depth_funcs_alpha_testing/gl_png.c b/samples/depth_funcs_alpha_testing/gl_png.c
new file mode 100644
index 0000000..05dedc4
--- /dev/null
+++ b/samples/depth_funcs_alpha_testing/gl_png.c
@@ -0,0 +1,237 @@
+#include <kos.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <GL/gl.h>
+#include <GL/glkos.h>
+#include <GL/glext.h>
+#include <GL/glu.h>
+
+#include "gl_png.h"
+
+#define CLEANUP(x) { ret = (x); goto cleanup; }
+
+GLfloat global_diffuse[] = {1.0, 1.0, 1.0, 1.0};
+GLfloat global_ambient[] = {1.0, 1.0, 1.0, 1.0};
+
+
+int dtex_to_gl_texture(texture *tex, char* filename) {
+    // Load Texture
+    Image *image;
+
+    // allocate space for texture
+    image = (Image *) malloc(sizeof(Image));
+    if (image == NULL) {
+				printf("No memory for .DTEX file\n");
+				return(0);
+    }
+
+		FILE* file = NULL;
+
+		// make sure the file is there.
+		if ((file = fopen(filename, "rb")) == NULL)
+		{
+			printf("File not found");
+				return 0;
+		}
+
+		struct {
+				char	id[4];	// 'DTEX'
+				GLushort	width;
+				GLushort	height;
+				GLuint		type;
+				GLuint		size;
+		} header;
+
+		fread(&header, sizeof(header), 1, file);
+
+		GLboolean twiddled = (header.type & (1 << 26)) < 1;
+		GLboolean compressed = (header.type & (1 << 30)) > 0;
+		GLboolean mipmapped = (header.type & (1 << 31)) > 0;
+		GLboolean strided = (header.type & (1 << 25)) > 0;
+		GLuint 		format = (header.type >> 27) & 0b111;
+
+		image->data = (char *) malloc (header.size);
+		image->sizeX = header.width;
+		image->sizeY = header.height;
+		image->dataSize = header.size;
+
+		GLuint expected = 2 * header.width * header.height;
+		GLuint ratio = (GLuint) (((GLfloat) expected) / ((GLfloat) header.size));
+
+		fread(image->data, image->dataSize, 1, file);
+		fclose(file);
+
+		if(compressed) {
+				printf("Compressed - ");
+				if(twiddled) {
+					printf("Twiddled - ");
+						switch(format) {
+								case 0: {
+										if(mipmapped) {
+												image->internalFormat = GL_COMPRESSED_ARGB_1555_VQ_MIPMAP_TWID_KOS;
+										} else {
+												image->internalFormat = GL_COMPRESSED_ARGB_1555_VQ_TWID_KOS;
+										}
+								} break;
+								case 1: {
+										if(mipmapped) {
+												image->internalFormat = GL_COMPRESSED_RGB_565_VQ_MIPMAP_TWID_KOS;
+										} else {
+												image->internalFormat = GL_COMPRESSED_RGB_565_VQ_TWID_KOS;
+										}
+								} break;
+								case 2: {
+										if(mipmapped) {
+												image->internalFormat = GL_COMPRESSED_ARGB_4444_VQ_MIPMAP_TWID_KOS;
+										} else {
+												image->internalFormat = GL_COMPRESSED_ARGB_4444_VQ_TWID_KOS;
+										}
+								}
+								break;
+								default:
+										fprintf(stderr, "Invalid texture format");
+										return 0;
+						}
+				} else {
+						switch(format) {
+								case 0: {
+										if(mipmapped) {
+												image->internalFormat = GL_COMPRESSED_ARGB_1555_VQ_MIPMAP_KOS;
+										} else {
+												image->internalFormat = GL_COMPRESSED_ARGB_1555_VQ_KOS;
+										}
+								} break;
+								case 1: {
+										if(mipmapped) {
+												image->internalFormat = GL_COMPRESSED_RGB_565_VQ_MIPMAP_KOS;
+										} else {
+												image->internalFormat = GL_COMPRESSED_RGB_565_VQ_KOS;
+										}
+								} break;
+								case 2: {
+										if(mipmapped) {
+												image->internalFormat = GL_COMPRESSED_ARGB_4444_VQ_MIPMAP_KOS;
+										} else {
+												image->internalFormat = GL_COMPRESSED_ARGB_4444_VQ_KOS;
+										}
+								}
+								break;
+								default:
+										fprintf(stderr, "Invalid texture format");
+										return 0;
+						}
+				}
+		} else {
+			printf("Uncompressed - ");
+			//printf("Color:%u -", format);
+				switch(format) {
+
+						case 0:
+								image->internalFormat = GL_UNSIGNED_SHORT_1_5_5_5_REV_TWID_KOS;
+								//image->internalFormat = GL_UNSIGNED_SHORT_1_5_5_5_REV;
+						break;
+						case 1:
+								image->internalFormat = GL_UNSIGNED_SHORT_5_6_5_REV;
+						break;
+						case 2:
+								image->internalFormat = GL_UNSIGNED_SHORT_4_4_4_4_REV;
+						break;
+			}
+		}
+		printf("\n");
+
+		// Create Texture
+		GLuint texture_id;
+    glGenTextures(1, &texture_id);
+    glBindTexture(GL_TEXTURE_2D, texture_id);   // 2d texture (x and y size)
+
+		GLint newFormat = format;
+		GLint colorType = GL_RGB;
+
+		if (image->internalFormat == GL_UNSIGNED_SHORT_1_5_5_5_REV_TWID_KOS ||
+				image->internalFormat == GL_UNSIGNED_SHORT_4_4_4_4_REV){
+					 newFormat = GL_BGRA;
+					 colorType = GL_RGBA;
+					 printf("Reversing RGBA\n");
+			}
+
+		if (image->internalFormat == GL_UNSIGNED_SHORT_5_6_5_REV){
+					 newFormat = GL_RGB;
+					 colorType = GL_RGB;
+					 printf("Reversing RGB\n");
+			}
+
+		glTexImage2D(GL_TEXTURE_2D, 0,
+			colorType, image->sizeX, image->sizeY, 0,
+			newFormat, image->internalFormat, image->data);
+
+		tex->id = texture_id;
+		tex->w = image->sizeX;
+		tex->h = image->sizeY;
+		tex->u = 0.f;
+		tex->v = 0.f;
+		tex->a = tex->light = 1;
+		tex->color[0] = tex->color[1] = tex->color[2] = 1.0f;
+		tex->uSize = tex->vSize = 1.0f;
+		tex->xScale = tex->yScale = 1.0f;
+		tex->format = image->internalFormat;
+		tex->min_filter = tex->mag_filter = GL_NEAREST;
+		tex->blend_source = GL_SRC_ALPHA;
+		tex->blend_dest = GL_ONE_MINUS_SRC_ALPHA;
+		strcpy(tex->path, filename);
+
+		printf("Texture size: %d x %d\n", image->sizeX, image->sizeY);
+		printf("Texture ratio: %d\n", ratio);
+		printf("Texture size: %d x %d\n", image->sizeX, image->sizeY);
+		printf("Texture %s loaded\n", tex->path);
+
+		return(1);
+};
+
+void draw_textured_quad(texture *tex) {
+	if(glIsTexture(tex->id)) {
+
+		GLfloat vertex_data[] = {
+			/* 2D Coordinate, texture coordinate */
+			0, 1, 0,
+			1, 1, 0,
+			1, 0, 0,
+			0, 0, 0
+		};
+
+		GLfloat uv_data[] = {
+			/* 2D Coordinate, texture coordinate */
+			0, 1,
+			1, 1,
+			1, 0,
+			0, 0
+		};
+
+		GLfloat normal_data[] = {
+			/* 2D Coordinate, texture coordinate */
+			0.0, 0.0, 1.0,
+			0.0, 0.0, 1.0,
+			0.0, 0.0, 1.0,
+			0.0, 0.0, 1.0
+		};
+
+		glEnable(GL_TEXTURE_2D);
+		glBindTexture(GL_TEXTURE_2D, tex->id);
+		glEnableClientState(GL_VERTEX_ARRAY);
+		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+		glEnableClientState(GL_NORMAL_ARRAY);
+
+		glVertexPointer			(3, GL_FLOAT, 0, vertex_data);
+		glTexCoordPointer		(2, GL_FLOAT, 0, uv_data);
+		glNormalPointer			(GL_FLOAT, 0, normal_data);
+
+		glDrawArrays(GL_QUADS, 0, 4);
+
+		glDisableClientState(GL_VERTEX_ARRAY);
+		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+		glDisableClientState(GL_NORMAL_ARRAY);
+		glDisable(GL_TEXTURE_2D);
+	}
+}
diff --git a/samples/depth_funcs_alpha_testing/gl_png.h b/samples/depth_funcs_alpha_testing/gl_png.h
new file mode 100644
index 0000000..21070b7
--- /dev/null
+++ b/samples/depth_funcs_alpha_testing/gl_png.h
@@ -0,0 +1,42 @@
+#ifndef __GL_PNG_H__
+#define __GL_PNG_H__
+
+#include <stdio.h>
+#include <kos.h>
+#include <GL/gl.h>
+
+typedef struct _texture {
+	GLuint 		id;
+	GLenum 		format;
+	GLenum 		min_filter;
+	GLenum 		mag_filter;
+	GLenum		blend_source;
+	GLenum		blend_dest;
+	int 			loaded;
+	uint16_t 	w, h; // width / height of texture image
+	int				size[2];
+	float 		u, v; //uv COORD
+	float 		uSize, vSize; // uvSize
+	float 		xScale, yScale; //render scale
+	float 		a; //alpha
+	float 		light; //alpha
+	float 		color[3];
+	char  		path[32];
+} texture;
+
+/* DTEX Image type - contains height, width, and data */
+typedef struct Image {
+    unsigned long sizeX;
+    unsigned long sizeY;
+    char 					*data;
+    GLenum 				internalFormat;
+    GLboolean 		mipmapped;
+    unsigned int 	dataSize;
+} Image;
+
+
+int 	dtex_to_gl_texture(texture *tex, char* filename);
+void 	draw_textured_quad(texture *tex);
+
+
+#endif
diff --git a/samples/depth_funcs_alpha_testing/gl_png.h.gch b/samples/depth_funcs_alpha_testing/gl_png.h.gch
new file mode 100644
index 0000000..c2e3e27
Binary files /dev/null and b/samples/depth_funcs_alpha_testing/gl_png.h.gch differ
diff --git a/samples/depth_funcs_alpha_testing/main.c b/samples/depth_funcs_alpha_testing/main.c
new file mode 100644
index 0000000..f6bb1eb
--- /dev/null
+++ b/samples/depth_funcs_alpha_testing/main.c
@@ -0,0 +1,110 @@
+#include "gl.h"
+#include "glu.h"
+#include "glkos.h"
+#include  "gl_png.h"
+
+//$KOS_BASE/utils/texconv/texconv  --in disk.png --format ARGB4444 --preview disk_preview.png --out disk.dtex
+
+extern uint8 romdisk[];
+KOS_INIT_ROMDISK(romdisk);
+texture t;
+int 	blendActive = -1;
+/* floats for x rotation, y rotation, z rotation */
+float xrot, yrot, zrot;
+
+/* A general OpenGL initialization function.  Sets all of the initial parameters. */
+void InitGL(int Width, int Height)	        // We call this right after our OpenGL window is created.
+{
+    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);		// This Will Clear The Background Color To Black
+    glClearDepth(1.0);				// Enables Clearing Of The Depth Buffer
+    glShadeModel(GL_SMOOTH);			// Enables Smooth Color Shading
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();				// Reset The Projection Matrix
+    gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height,0.1f,100.0f);	// Calculate The Aspect Ratio Of The Window
+    glEnable(GL_TEXTURE_2D);
+    glMatrixMode(GL_MODELVIEW);
+}
+
+/* The function called when our window is resized (which shouldn't happen, because we're fullscreen) */
+void ReSizeGLScene(int Width, int Height)
+{
+    if (Height == 0)				// Prevent A Divide By Zero If The Window Is Too Small
+        Height = 1;
+
+    glViewport(0, 0, Width, Height);		// Reset The Current Viewport And Perspective Transformation
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+
+    gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height,0.1f,100.0f);
+    glMatrixMode(GL_MODELVIEW);
+}
+
+
+void DrawSquare(float width, float r, float g, float b, float z) {
+    width /= 2;
+
+    glColor3f(r, g, b);
+    glBegin(GL_QUADS);				// start drawing a polygon (4 sided)
+    glVertex3f(-width, width, z);		// Top Left
+    glVertex3f( width, width, z);		// Top Right
+    glVertex3f( width,-width, z);		// Bottom Right
+    glVertex3f(-width,-width, z);		// Bottom Left
+    glEnd();					// done with the polygon
+}
+
+/* The main drawing function. */
+void DrawGLScene()
+{
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	// Clear The Screen And The Depth Buffer
+    glLoadIdentity();				// Reset The View
+
+
+    //First Batch is alpha blending
+    glTranslated(-1 ,0, -5);
+    for (int i = 0; i < 5; i++) {
+      glTranslated(0.5, 0, 0);
+      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+      glEnable(GL_BLEND);
+      draw_textured_quad(&t);
+      glDisable(GL_BLEND);
+    }
+
+
+    //Second batch is depth testing
+    //Changing the translate Z value doesn't change anything?
+    glLoadIdentity();
+    glTranslated(-1 , -1, -5);
+    glDepthFunc(GL_LESS);
+    glEnable(GL_DEPTH_FUNC);
+
+    for (int i = 0; i < 5; i++) {
+      glTranslated(0.5, 0, -0.2);
+      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+      glEnable(GL_BLEND);
+      draw_textured_quad(&t);
+      glDisable(GL_BLEND);
+    }
+
+    glDisable(GL_DEPTH_TEST);
+
+    // swap buffers to display, since we're double buffered.
+    glKosSwapBuffers();
+}
+
+int main(int argc, char **argv)
+{
+    glKosInit();
+    InitGL(640, 480);
+
+    //loads a dtex texture. see the /romdisk folder for more files
+    dtex_to_gl_texture(&t, "/rd/disk_1555.dtex");
+    ReSizeGLScene(640, 480);
+    DrawGLScene();
+    while(1) {
+      DrawGLScene();
+    }
+
+    return 0;
+}
diff --git a/samples/depth_funcs_alpha_testing/romdisk/convertToDtex.sh b/samples/depth_funcs_alpha_testing/romdisk/convertToDtex.sh
new file mode 100755
index 0000000..9443d16
--- /dev/null
+++ b/samples/depth_funcs_alpha_testing/romdisk/convertToDtex.sh
@@ -0,0 +1,17 @@
+#! /bin/sh
+
+FILE=$1
+FILE_FLIP="$1_flip.png"
+FILE_PATH=${FILE%/*}
+
+echo $FILE_PATH
+
+convert $FILE -flip $FILE_FLIP
+
+$KOS_BASE/utils/texconv/texconv --in $FILE_FLIP --format ARGB1555 --preview $FILE_PATH/preview_1555.png --out $FILE_PATH/disk_1555.dtex
+$KOS_BASE/utils/texconv/texconv --in $FILE_FLIP --format RGB565 --preview $FILE_PATH/preview_565.png --out $FILE_PATH/disk_565.dtex
+$KOS_BASE/utils/texconv/texconv --in $FILE_FLIP --format ARGB4444 --preview $FILE_PATH/preview_4444.png --out $FILE_PATH/disk_4444.dtex
+
+rm $FILE_FLIP
+
+#rm $FILE_FLIP
diff --git a/samples/depth_funcs_alpha_testing/romdisk/disk.png b/samples/depth_funcs_alpha_testing/romdisk/disk.png
new file mode 100644
index 0000000..a5d83c1
Binary files /dev/null and b/samples/depth_funcs_alpha_testing/romdisk/disk.png differ
diff --git a/samples/depth_funcs_alpha_testing/romdisk/disk_1555.dtex b/samples/depth_funcs_alpha_testing/romdisk/disk_1555.dtex
new file mode 100644
index 0000000..1502c1d
Binary files /dev/null and b/samples/depth_funcs_alpha_testing/romdisk/disk_1555.dtex differ
diff --git a/samples/depth_funcs_alpha_testing/romdisk/disk_4444.dtex b/samples/depth_funcs_alpha_testing/romdisk/disk_4444.dtex
new file mode 100644
index 0000000..4f7d08a
Binary files /dev/null and b/samples/depth_funcs_alpha_testing/romdisk/disk_4444.dtex differ
diff --git a/samples/depth_funcs_alpha_testing/romdisk/disk_565.dtex b/samples/depth_funcs_alpha_testing/romdisk/disk_565.dtex
new file mode 100644
index 0000000..5357c9d
Binary files /dev/null and b/samples/depth_funcs_alpha_testing/romdisk/disk_565.dtex differ
diff --git a/samples/depth_funcs_alpha_testing/romdisk/preview_1555.png b/samples/depth_funcs_alpha_testing/romdisk/preview_1555.png
new file mode 100644
index 0000000..d5d0c07
Binary files /dev/null and b/samples/depth_funcs_alpha_testing/romdisk/preview_1555.png differ
diff --git a/samples/depth_funcs_alpha_testing/romdisk/preview_4444.png b/samples/depth_funcs_alpha_testing/romdisk/preview_4444.png
new file mode 100644
index 0000000..d328267
Binary files /dev/null and b/samples/depth_funcs_alpha_testing/romdisk/preview_4444.png differ
diff --git a/samples/depth_funcs_alpha_testing/romdisk/preview_565.png b/samples/depth_funcs_alpha_testing/romdisk/preview_565.png
new file mode 100644
index 0000000..48bcc2b
Binary files /dev/null and b/samples/depth_funcs_alpha_testing/romdisk/preview_565.png differ
diff --git a/samples/depth_funcs_alpha_testing/romdisk/spritesheet.dtex b/samples/depth_funcs_alpha_testing/romdisk/spritesheet.dtex
new file mode 100644
index 0000000..b4b0759
Binary files /dev/null and b/samples/depth_funcs_alpha_testing/romdisk/spritesheet.dtex differ