#include <jni.h>
#include <android/log.h>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <sstream>
#include <string>
#include "Common.h"
#include "Matrix.h"
#include "Native.h"
#include "Texture.h"
#include "Timer.h"
#include "Shader.h"

Functions
void	initialize3DTexture ()
	Initializes OpenGL ES texture components. More...

void	initializeAttribArrays ()
	Initializes input vertex data for shaders. More...

void	initializeProgram ()
	Creates program and attaches shaders to it. More...

void	initializeTextureData ()
	Fills 3D texture with images. More...

void	initializeUniformData ()
	Initializes uniform variables in program. More...

void	loadImages ()
	Loads imagesCount images located in resourceDirectory. More...

void	loadUniformTextures (int count)
	Creates and loads count unicolor layers to a 3D texture. More...

void	renderFrame ()
	Renders single frame. More...

void	setBlendEquation (GLboolean isMinBlending)
	Sets current blending equation. More...

void	setNextTextureImage (GLvoid *textureData)
	Fills next empty 3D texture layer with textureData. More...

void	setupGraphics (int width, int height)
	Initializes OpenGL ES context. More...

void	uninit ()
	Releases OpenGL ES objects. More...

JNIEXPORT void JNICALL	Java_com_arm_malideveloper_openglessdk_minMaxBlending_NativeLibrary_init (JNIEnv *, jobject, jint width, jint height)

JNIEXPORT void JNICALL	Java_com_arm_malideveloper_openglessdk_minMaxBlending_NativeLibrary_step (JNIEnv *, jobject)

JNIEXPORT void JNICALL	Java_com_arm_malideveloper_openglessdk_minMaxBlending_NativeLibrary_uninit (JNIEnv *, jobject)

Variables
const string	resourceDirectory = "/data/data/com.arm.malideveloper.openglessdk.minMaxBlending/files/"

const string	imagesFilename = "MRbrain"

const int	imagesCount = 109

Timer	timer

int	windowWidth = 0

int	windowHeight = 0

const GLint	textureWidth = 256

const GLint	textureHeight = 256

const GLint	textureDepth = 128

const GLfloat	minBlendingThreshold = 0.37f

const short	fillerLuminance = 4

GLuint	textureID = 0

GLuint	programID = 0

GLuint	verticesBufferID = 0

GLuint	uvwBufferID = 0

GLuint	vaoID = 0

GLint	isMinBlendingLocation = -1

GLint	rotationVectorLocation = -1

GLint	textureZOffset = 0

GLboolean	isMinBlending = GL_FALSE

const float	resetTimeInterval = 5.0f

const float	squareVertices []

const float	uvwCoordinates []

Detailed Description

The application demonstrates behaviour of blending in GL_MIN and GL_MAX mode. It renders a 3D texture which consists of a series of greyscaled images obtained from magnetic resonance of a human head. The images are placed one after another in Z axis, so when blending is enabled they imitate a 3D model of the head.

Texture coordinates are then rotated, so viewers can see the model from different perspectives and after each 5 seconds, blending equation is changed. Since U/V/W coordinates are taken from interval <0.0, 1.0> and they are clamped to edge, there might occure some distortions for specific angles of rotation. That is why, the application adds a few blank layers behind and in the front of the original images. Now, if rotated coordinates exceed the interval, only the additional edge layers are repeated creating a noiseless background.

Because images contain a lot of black color, regular min blending would result in having black square on the screen. Hence, there is a threshold applied in fragment shader which prevents rendering fragments that are not bright enough. Additionally, for both types of blending, contrast of output luminance had to be modified to see more details.

To use your own input images, it is check their format and adjust values of min blending threshold, luminance of additional edge layers and contrast modifier.

Definition in file Native.cpp.

Function Documentation

void initialize3DTexture ( )

Initializes OpenGL ES texture components.

Definition at line 149 of file Native.cpp.

void initializeAttribArrays ( )

Initializes input vertex data for shaders.

Definition at line 183 of file Native.cpp.

void initializeProgram ( )

Creates program and attaches shaders to it.

Definition at line 220 of file Native.cpp.

void initializeTextureData ( )

Fills 3D texture with images.

Definition at line 250 of file Native.cpp.

void initializeUniformData ( )

Initializes uniform variables in program.

Definition at line 274 of file Native.cpp.

JNIEXPORT void JNICALL Java_com_arm_malideveloper_openglessdk_minMaxBlending_NativeLibrary_init	(	JNIEnv *	,
		jobject	,
		jint	width,
		jint	height
	)

Definition at line 534 of file Native.cpp.

JNIEXPORT void JNICALL Java_com_arm_malideveloper_openglessdk_minMaxBlending_NativeLibrary_step	(	JNIEnv *	,
		jobject
	)

Definition at line 539 of file Native.cpp.

JNIEXPORT void JNICALL Java_com_arm_malideveloper_openglessdk_minMaxBlending_NativeLibrary_uninit	(	JNIEnv *	,
		jobject
	)

Definition at line 544 of file Native.cpp.

void loadImages ( )

Loads imagesCount images located in resourceDirectory.

Definition at line 333 of file Native.cpp.

void loadUniformTextures ( int count )

Creates and loads count unicolor layers to a 3D texture.

Parameters

count Number of layers to be filled.

Definition at line 362 of file Native.cpp.

void renderFrame ( void )

Renders single frame.

Definition at line 385 of file Native.cpp.

void setBlendEquation ( GLboolean isMinBlending )

Sets current blending equation.

Parameters

isMinBlending True, if GL_MIN blending mode should be used.

Definition at line 433 of file Native.cpp.

void setNextTextureImage ( GLvoid * textureData )

Fills next empty 3D texture layer with textureData.

It is called by the functions which prepare texture data either by creating it inside the application or loading it from from a file.

Parameters

textureData Data the 3D texture is filled with.

Definition at line 459 of file Native.cpp.

void setupGraphics	(	int	width,
		int	height
	)

Initializes OpenGL ES context.

Parameters

width	Window resolution: width.
height	Window resolution: height.

Definition at line 486 of file Native.cpp.

void uninit ( )

Releases OpenGL ES objects.

It should be called before leaving the application.

Definition at line 518 of file Native.cpp.

Variable Documentation

const short fillerLuminance = 4

Definition at line 84 of file Native.cpp.

const int imagesCount = 109

Definition at line 65 of file Native.cpp.

const string imagesFilename = "MRbrain"

Definition at line 62 of file Native.cpp.

GLboolean isMinBlending = GL_FALSE

Definition at line 110 of file Native.cpp.

GLint isMinBlendingLocation = -1

Definition at line 101 of file Native.cpp.

const GLfloat minBlendingThreshold = 0.37f

Definition at line 82 of file Native.cpp.

GLuint programID = 0

Definition at line 90 of file Native.cpp.

const float resetTimeInterval = 5.0f

Definition at line 113 of file Native.cpp.

const string resourceDirectory = "/data/data/com.arm.malideveloper.openglessdk.minMaxBlending/files/"

Definition at line 61 of file Native.cpp.

GLint rotationVectorLocation = -1

Definition at line 102 of file Native.cpp.

const float squareVertices[]

Initial value:

=
{
    -1.0f,  1.0f, -1.0f, 1.0f,
     1.0f,  1.0f, -1.0f, 1.0f,
    -1.0f, -1.0f, -1.0f, 1.0f,
    -1.0f, -1.0f, -1.0f, 1.0f,
     1.0f,  1.0f, -1.0f, 1.0f,
     1.0f, -1.0f, -1.0f, 1.0f,
}

Definition at line 127 of file Native.cpp.

const GLint textureDepth = 128

Definition at line 79 of file Native.cpp.

const GLint textureHeight = 256

Definition at line 78 of file Native.cpp.

GLuint textureID = 0

Definition at line 87 of file Native.cpp.

const GLint textureWidth = 256

Definition at line 77 of file Native.cpp.

GLint textureZOffset = 0

Definition at line 107 of file Native.cpp.

Timer timer

Definition at line 68 of file Native.cpp.

GLuint uvwBufferID = 0

Definition at line 95 of file Native.cpp.

const float uvwCoordinates[]

Initial value:

=
{
    0.0f, 0.0f, 1.0f,
    1.0f, 0.0f, 1.0f,
    0.0f, 1.0f, 1.0f,
    0.0f, 1.0f, 1.0f,
    1.0f, 0.0f, 1.0f,
    1.0f, 1.0f, 1.0f,
}

Definition at line 138 of file Native.cpp.

GLuint vaoID = 0

Definition at line 98 of file Native.cpp.

GLuint verticesBufferID = 0

Definition at line 93 of file Native.cpp.

int windowHeight = 0

Definition at line 72 of file Native.cpp.

int windowWidth = 0

Definition at line 71 of file Native.cpp.

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation