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I am trying to change my OpenGL square's color only when it is touched. I looked around online at some good sources to see how I could find the coordinates to change its color, Converting pixel co-ordinates to normalized co-ordinates at draw time in OpenGL 3.0. However, I am still confused about how to get my square's or onTouchEvent inputs coordinates to be translated in OpenGL code(vertexShaderCode). I have tried to directly track my square coordinates in the onTouchEvent activity, but it wrongly tracks the position since I am working with two different coordinate systems(OpenGl, Android Studios).
//THIS IS NOT MY FULL CODE
public boolean onTouchEvent(MotionEvent e) {
// MotionEvent reports input details from the touch screen
// and other input controls. In this case, you are only
// interested in events where the touch position changed.
float x = e.getX();
float y = e.getY();
colorHolder = renderer.getmSquare().getColor();
switch (e.getAction()) {
case MotionEvent.ACTION_DOWN:
//THIS IS MY PROBLEM. I DON'T KNOW A GOOD WAY OF TRACKING THE SQUARE'S POSITION BESIDES
//ADDING VARIBLE TO IT'S MAIN CLASS THEN REFERENCING THEM HERE
if(renderer.mSquareY > (y / getHeight()) && renderer.mSquareX > (x / getWidth()))
renderer.getmSquare().color = tempColor;
case MotionEvent.ACTION_MOVE:
float dx = x - previousX;
float dy = y - previousY;
float tempHeight = y / getHeight();
float tempWidth = x / getWidth();
//THIS IS MY PROBLEM. I DON'T KNOW A GOOD WAY OF TRACKING THE SQUARE'S POSITION BESIDES ADDING VARIBLE TO IT'S MAIN CLASS THEN REFERENCING THEM HERE
if(renderer.mSquareY < (y / getHeight()) && renderer.mSquareX < (x / getWidth()))
renderer.getmSquare().color = tempColor;
renderer.mSquareX = (x / getWidth());
renderer.mSquareY = (y / getHeight());
...
I have three classes that handle creating the square, handles rendering, and the main activity in the corresponding order: Square.java, MyGLRenderer.java, MyGLSurfaceView.java.
public class Square {
private final String vertexShaderCode =
// This matrix member variable provides a hook to manipulate
// the coordinates of the objects that use this vertex shader
"uniform mat4 uMVPMatrix;" +
"attribute vec4 vPosition;" +
"void main() {" +
// The matrix must be included as a modifier of gl_Position.
// Note that the uMVPMatrix factor *must be first* in order
// for the matrix multiplication product to be correct.
" gl_Position = uMVPMatrix * vPosition;" +
"}";
private final String fragmentShaderCode =
"precision mediump float;" +
"uniform vec4 vColor;" +
"void main() {" +
" gl_FragColor = vColor;" +
"}";
private FloatBuffer vertexBuffer;
private ShortBuffer drawListBuffer;
private final int mProgram;
private int mPositionHandle;
private int mColorHandle;
private int mMVPMatrixHandle;
// number of coordinates per vertex in this array
static final int COORDS_PER_VERTEX = 3;
static float squareCoords[] = {
0.5f, 0.5f, 0.0f, // top left
0.5f, -0.5f, 0.0f, // bottom left
-0.5f, -0.5f, 0.0f, // bottom right
-0.5f, 0.5f, 0.0f }; // top right
private short drawOrder[] = { 0, 1, 2, 0, 2, 3 }; // order to draw vertices
private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex
public float[] getColor() {
return color;
}
public void setColor(float[] color) {
this.color = color;
}
float color[] = { 0.2f, 0.709803922f, 0.898039216f, 1.0f };
public Square() {
// initialize vertex byte buffer for shape coordinates
ByteBuffer bb = ByteBuffer.allocateDirect(
// (# of coordinate values * 4 bytes per float)
squareCoords.length * 4);
bb.order(ByteOrder.nativeOrder());
vertexBuffer = bb.asFloatBuffer();
vertexBuffer.put(squareCoords);
vertexBuffer.position(0);
// initialize byte buffer for the draw list
ByteBuffer dlb = ByteBuffer.allocateDirect(
// (# of coordinate values * 2 bytes per short)
drawOrder.length * 2);
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(drawOrder);
drawListBuffer.position(0);
// prepare shaders and OpenGL program
int vertexShader = MyGLRenderer.loadShader(
GLES20.GL_VERTEX_SHADER,
vertexShaderCode);
int fragmentShader = MyGLRenderer.loadShader(
GLES20.GL_FRAGMENT_SHADER,
fragmentShaderCode);
mProgram = GLES20.glCreateProgram(); // create empty OpenGL Program
GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program
GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
GLES20.glLinkProgram(mProgram); // create OpenGL program executables
}
public void draw(float[] mvpMatrix) {
// Add program to OpenGL environment
GLES20.glUseProgram(mProgram);
// get handle to vertex shader's vPosition member
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
// Enable a handle to the triangle vertices
GLES20.glEnableVertexAttribArray(mPositionHandle);
// Prepare the triangle coordinate data
GLES20.glVertexAttribPointer(
mPositionHandle, COORDS_PER_VERTEX,
GLES20.GL_FLOAT, false,
vertexStride, vertexBuffer);
// get handle to fragment shader's vColor member
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
// Set color for drawing the triangle
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
// get handle to shape's transformation matrix
mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
//MyGLRenderer.checkGlError("glGetUniformLocation");
// Apply the projection and view transformation
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0);
//MyGLRenderer.checkGlError("glUniformMatrix4fv");
// Draw the square
GLES20.glDrawElements(
GLES20.GL_TRIANGLES, drawOrder.length,
GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
// Disable vertex array
GLES20.glDisableVertexAttribArray(mPositionHandle);
}
}
public class MyGLRenderer implements GLSurfaceView.Renderer {
private Triangle mTriangle;
public Square getmSquare() {
return mSquare;
}
public void setmSquare(Square mSquare) {
this.mSquare = mSquare;
}
private Square mSquare;
private Circle mCircle;
// vPMatrix is an abbreviation for "Model View Projection Matrix"
private final float[] vPMatrix = new float[16];
private final float[] projectionMatrix = new float[16];
private final float[] viewMatrix = new float[16];
private float[] rotationMatrix = new float[16];
private float[] translationMatrix = new float[16];
private float[] scaleMatrix = new float[16];
public volatile float mAngle;
public float mSquareX = 1.5f;
public float mSquareY = 0.0f;
public float mRadius = 1.0f;
public float getAngle() {
return mAngle;
}
public void setAngle(float angle) {
mAngle = angle;
}
public void onSurfaceCreated(GL10 unused, EGLConfig eglconfig) {
// Set the background frame color
GLES20.glClearColor(0.0f, 0.0f, 1.0f, 1.0f);
// initialize a triangle
mTriangle = new Triangle();
// initialize a square
mSquare = new Square();
// initialize a square
mCircle = new Circle();
}
#Override
public void onDrawFrame(GL10 unused) {
float[] scratch = new float[16];
float[] movementSquare = new float[16];
float[] scaleCircle = new float[16];
float tempscaleFactor = 1.0f * mRadius;
// Redraw background color
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
// Set the camera position (View matrix)
Matrix.setLookAtM(viewMatrix, 0, 0, 0, -3, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
// Calculate the projection and view transformation
Matrix.multiplyMM(vPMatrix, 0, projectionMatrix, 0, viewMatrix, 0);
// Create a rotation transformation for the triangle
//long time = SystemClock.uptimeMillis() % 4000L;
//float angle = 0.090f * ((int) time);
Matrix.setRotateM(rotationMatrix, 0, mAngle, 0, 0, -1.0f);
Matrix.setIdentityM(translationMatrix,0);
Matrix.translateM(translationMatrix, 0, mSquareX, mSquareY,0);
//THIS PROBLEM HERE IS THAT MY CIRCLE TRANSLATE'S ON THE X-AXIS WHEN SCALING. MY GOAL IS TO TRY AND KEEP IT IN PLACE WHILE IT'S BEING SCALED. Y-AXIS HAS NOT ISSUES
Matrix.setIdentityM(scaleMatrix, 0);
Matrix.scaleM(scaleMatrix, 0, mRadius, mRadius, 0);
if(mRadius != 1f)
Matrix.translateM(scaleMatrix, 0, -(1 + (mRadius / 2)),0,0);
// Combine the rotation matrix with the projection and camera view
// Note that the vPMatrix factor *must be first* in order
// for the matrix multiplication product to be correct.
Matrix.multiplyMM(movementSquare, 0, vPMatrix, 0, translationMatrix, 0);
Matrix.multiplyMM(scratch, 0, vPMatrix, 0, rotationMatrix, 0);
Matrix.multiplyMM(scaleCircle, 0, vPMatrix, 0, scaleMatrix, 0);
// Draw shape
mTriangle.draw(scratch);
mSquare.draw(movementSquare);
mCircle.draw(scaleCircle);
}
#Override
public void onSurfaceChanged(GL10 unused, int width, int height) {
GLES20.glViewport(0, 0, width, height);
float ratio = (float) width / height;
// this projection matrix is applied to object coordinates
// in the onDrawFrame() method
Matrix.frustumM(projectionMatrix, 0, -ratio, ratio, -1, 1, 2, 7);
}
public static int loadShader(int type, String shaderCode){
// create a vertex shader type (GLES20.GL_VERTEX_SHADER)
// or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
// add the source code to the shader and compile it
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
}
i been trying to implement a 3D animation in openGL (using JOGL) of a solar system so far i have 5 planets of different sizes but the problem i seem to be having is i cant add a map of the earth texture on a Sphere can anybody help me on how its done?
This is the code i have so far in my Display method:
#Override
public void display(GLAutoDrawable drawable) {
GL2 gl = drawable.getGL().getGL2();
GLU glu = new GLU();
gl.glClear(GL.GL_COLOR_BUFFER_BIT);
//make sure we are in model_view mode
gl.glMatrixMode(GL2.GL_MODELVIEW);
gl.glLoadIdentity();
glu.gluLookAt(10,20,20,0,3,0,0, 20, 0);
//gl.glMatrixMode(GL2.GL_PROJECTION);
//glu.gluPerspective(45,1,1,25);
//render ground plane
gl.glPushMatrix();
gl.glTranslatef(-10.75f, 3.0f, -1.0f);
gl.glColor3f(0.3f, 0.5f, 1f);
GLUquadric earth = glu.gluNewQuadric();
glu.gluQuadricDrawStyle(earth, GLU.GLU_FILL);
glu.gluQuadricNormals(earth, GLU.GLU_FLAT);
glu.gluQuadricOrientation(earth, GLU.GLU_OUTSIDE);
final float radius = 3.378f;
final int slices = 89;
final int stacks = 16;
glu.gluSphere(earth, radius, slices, stacks);
glu.gluDeleteQuadric(earth);
Texture earths;
try {
earths = TextureIO.newTexture(new File("earth.png"), true);
}
catch (IOException e) {
javax.swing.JOptionPane.showMessageDialog(null, e);
}
gl.glPopMatrix();
//gl.glEnd();
gl.glPushMatrix();
gl.glTranslatef(2.75f, 3.0f, -0.0f);
gl.glColor3f(0.3f, 0.5f, 1f);
GLUquadric earth1 = glu.gluNewQuadric();
glu.gluQuadricDrawStyle(earth1, GLU.GLU_FILL);
glu.gluQuadricNormals(earth1, GLU.GLU_FLAT);
glu.gluQuadricOrientation(earth1, GLU.GLU_OUTSIDE);
final float radius1 = 3.378f;
final int slices1 = 90;
final int stacks1 = 63;
glu.gluSphere(earth1, radius1, slices1, stacks1);
glu.gluDeleteQuadric(earth1);
gl.glPopMatrix();
gl.glPushMatrix();
gl.glTranslatef(3.75f, 6.0f, -7.20f);
gl.glColor3f(0.3f, 0.5f, 1f);
GLUquadric earth3 = glu.gluNewQuadric();
glu.gluQuadricDrawStyle(earth3, GLU.GLU_FILL);
glu.gluQuadricNormals(earth3, GLU.GLU_FLAT);
glu.gluQuadricOrientation(earth1, GLU.GLU_OUTSIDE);
final float radius3 = 1.878f;
final int slices3 = 89;
final int stacks3 = 16;
glu.gluSphere(earth3, radius3, slices3, stacks3);
glu.gluDeleteQuadric(earth3);
gl.glPopMatrix();
gl.glPushMatrix();
gl.glTranslatef(12.75f, 2.0f, -7.20f);
gl.glColor3f(0.3f, 0.5f, 1f);
GLUquadric earth4 = glu.gluNewQuadric();
glu.gluQuadricDrawStyle(earth4, GLU.GLU_FILL);
glu.gluQuadricNormals(earth4, GLU.GLU_FLAT);
glu.gluQuadricOrientation(earth4, GLU.GLU_OUTSIDE);
final float radius4 = 1.078f;
final int slices4 = 89;
final int stacks4 = 16;
glu.gluSphere(earth4, radius4, slices4, stacks4);
glu.gluDeleteQuadric(earth4);
gl.glPopMatrix();
gl.glPushMatrix();
gl.glTranslatef(2.75f, -6.0f, -0.0f);
gl.glColor3f(0.3f, 0.5f, 1f);
GLUquadric earth5 = glu.gluNewQuadric();
glu.gluQuadricDrawStyle(earth5, GLU.GLU_FILL);
glu.gluQuadricNormals(earth5, GLU.GLU_FLAT);
glu.gluQuadricOrientation(earth5, GLU.GLU_OUTSIDE);
final float radius5 = 3.778f;
final int slices5 = 90;
final int stacks5 = 63;
glu.gluSphere(earth5, radius5, slices5, stacks5);
glu.gluDeleteQuadric(earth5);
gl.glPopMatrix();
}
create your own sphere mesh
simple 2D loop through 2 angles (spherical coordinate system 2 Cartesian). You can easily add ellipsoid properties (earth is not a sphere) if you want more precision. If not then you can use single sphere mesh for all planets and just scale it before use ...
let a be the longitude and b the latitude so loop a from 0 to 2*PI [rad] and b from -0.5*PI to +0.5*PI [rad] where PI=3.1415... is the Pi (in C++ math.h it is called M_PI). If your math api uses degrees then convert to degrees PI [rad] = 180.0 [deg]
add necessary info per vertex
normals for lighting
// just unit sphere
nx=cos(b)*cos(a);
ny=cos(b)*sin(a);
nz=sin(b);
texture coordinate (assuming rectangle non distorted image)
// just convert a,b to <0,1> range
tx=a/(2.0*PI)
ty=(b/PI)+0.5;
vertex position
// just sphere(rx=ry=rz=r) or ellipsoid (rx=ry=equatorial and rz=polar radius)
// can also use rx*nx,ry*ny,rz*nz instead ...
x=rx*cos(b)*cos(a);
y=ry*cos(b)*sin(a);
z=rz*sin(b);
send all of this to OpenGL
so all above store in some memory space (CPU or GPU) and then send to rendering. You can use legacy glBegin(QUAD_STRIP); ... glEnd(); or displaylist/VBO/VAO. Bind the right texture before each planet/body and do not forget to update ModelView matrix too. This is how mine coordinate systems looks like:
Also have a look at these related Q/As:
realistic n-body solar system
sphere mesh by subdivision
[edit1] C++ example
//---------------------------------------------------------------------------
const int nb=15; // slices
const int na=nb<<1; // points per equator
class planet
{
public:
bool _init; // has been initiated ?
GLfloat x0,y0,z0; // center of planet [GCS]
GLfloat pos[na][nb][3]; // vertex
GLfloat nor[na][nb][3]; // normal
GLfloat txr[na][nb][2]; // texcoord
GLuint txrid; // texture id
GLfloat t; // dayly rotation angle [deg]
planet() { _init=false; txrid=0; x0=0.0; y0=0.0; z0=0.0; t=0.0; }
~planet() { if (_init) glDeleteTextures(1,&txrid); }
void init(GLfloat r,AnsiString texture); // call after OpenGL is already working !!!
void draw();
};
void planet::init(GLfloat r,AnsiString texture)
{
if (!_init) { _init=true; glGenTextures(1,&txrid); }
GLfloat x,y,z,a,b,da,db;
GLfloat tx0,tdx,ty0,tdy;// just correction if CLAMP_TO_EDGE is not available
int ia,ib;
// a,b to texture coordinate system
tx0=0.0;
ty0=0.5;
tdx=0.5/M_PI;
tdy=1.0/M_PI;
// load texture to GPU memory
if (texture!="")
{
Byte q;
unsigned int *pp;
int xs,ys,x,y,adr,*txr;
union { unsigned int c32; Byte db[4]; } c;
Graphics::TBitmap *bmp=new Graphics::TBitmap; // new bmp
bmp->LoadFromFile(texture); // load from file
bmp->HandleType=bmDIB; // allow direct access to pixels
bmp->PixelFormat=pf32bit; // set pixel to 32bit so int is the same size as pixel
xs=bmp->Width; // resolution should be power of 2
ys=bmp->Height;
txr=new int[xs*ys];
for(adr=0,y=0;y<ys;y++)
{
pp=(unsigned int*)bmp->ScanLine[y];
for(x=0;x<xs;x++,adr++)
{
// rgb2bgr and copy bmp -> txr[]
c.c32=pp[x];
q =c.db[2];
c.db[2]=c.db[0];
c.db[0]=q;
txr[adr]=c.c32;
}
}
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D,txrid);
glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, xs, ys, 0, GL_RGBA, GL_UNSIGNED_BYTE, txr);
glDisable(GL_TEXTURE_2D);
delete bmp;
delete[] txr;
// texture coordinates by 1 pixel from each edge (GL_CLAMP_TO_EDGE)
tx0+=1.0/GLfloat(xs);
ty0+=1.0/GLfloat(ys);
tdx*=GLfloat(xs-2)/GLfloat(xs);
tdy*=GLfloat(ys-2)/GLfloat(ys);
}
// correct texture coordinate system (invert x)
tx0=1.0-tx0; tdx=-tdx;
da=(2.0*M_PI)/GLfloat(na-1);
db= M_PI /GLfloat(nb-1);
for (ib=0,b=-0.5*M_PI;ib<nb;ib++,b+=db)
for (ia=0,a= 0.0 ;ia<na;ia++,a+=da)
{
x=cos(b)*cos(a);
y=cos(b)*sin(a);
z=sin(b);
nor[ia][ib][0]=x;
nor[ia][ib][1]=y;
nor[ia][ib][2]=z;
pos[ia][ib][0]=r*x;
pos[ia][ib][1]=r*y;
pos[ia][ib][2]=r*z;
txr[ia][ib][0]=tx0+(a*tdx);
txr[ia][ib][1]=ty0+(b*tdy);
}
}
void planet::draw()
{
if (!_init) return;
int ia,ib0,ib1;
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glTranslatef(x0,y0,z0);
glRotatef(90.0,1.0,0.0,0.0); // rotate planets z axis (North) to OpenGL y axis (Up)
glRotatef(-t,0.0,0.0,1.0); // rotate planets z axis (North) to OpenGL y axis (Up)
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D,txrid);
glColor3f(1.0,1.0,1.0);
for (ib0=0,ib1=1;ib1<nb;ib0=ib1,ib1++)
{
glBegin(GL_QUAD_STRIP);
for (ia=0;ia<na;ia++)
{
glNormal3fv (nor[ia][ib0]);
glTexCoord2fv(txr[ia][ib0]);
glVertex3fv (pos[ia][ib0]);
glNormal3fv (nor[ia][ib1]);
glTexCoord2fv(txr[ia][ib1]);
glVertex3fv (pos[ia][ib1]);
}
glEnd();
}
glDisable(GL_TEXTURE_2D);
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
}
//---------------------------------------------------------------------------
usage:
// variable to store planet (global)
planet earth;
// init after OpenGL initialisation
earth.init(1.0,"earth.bmp");
// position update
earth.x0= 0.0;
earth.y0= 0.0;
earth.z0=-20.0;
// add this to render loop
earth.draw(); // draws the planet
earth.t+=2.5; // just rotate planet by 2.5 deg each frame...
I know its ugly but it does not use any funny stuff just legacy OpenGL and Math.h (cos(),sin(),M_PI) and VCL for bitmap loading. So rewrite to your environment and you will be fine. Do not forget that each planet has its own texture so you need to have one txrid per planet so either have each planet as separate planet variable or rewrite ...
I'm trying to create a 360 video sphere (like the ones for cardboard) on Android. I have done this with a photo by rendering a sphere in OpenGL ES1.0 and than attaching a texture to it. Afterwards I can use the sensor values to rotate the sphere.
However, I can't figure out how to change the picture to a video. I've tried frame by frame rendering using texSubImage2D() but it's SUPER SLOW. My video is probably going to be about 4k density as I need a good quality even when only small portion of it is shown.
I've read some theoretical stuff about how this should be done (i.e. Frame Buffers, External Texture, Synchronization, etc.) but I couldn't find any example for these things, so some code would be EXTREMELY appreciated...
Here is how I render the Sphere, draw it and attach a texture to it (i.e. my Sphere class)...
import rapid.decoder.BitmapDecoder;
public class Sphere {
/** Buffer holding the vertices. */
private final List<FloatBuffer> mVertexBuffer = new ArrayList<FloatBuffer>();
/** The vertices for the sphere. */
private final List<float[]> mVertices = new ArrayList<float[]>();
/** Buffer holding the texture coordinates. */
private final List<FloatBuffer> mTextureBuffer = new ArrayList<FloatBuffer>();
/** Mapping texture coordinates for the vertices. */
private final List<float[]> mTexture = new ArrayList<float[]>();
/** The texture pointer. */
private final int[] mTextures = new int[1];
/** Total number of strips for the given depth. */
private final int mTotalNumStrips;
public Sphere(final int depth, final float radius) {
// Calculate basic values for the sphere.
this.mTotalNumStrips = Maths.power(2, depth - 1) * 5; //last 5 is related to properties of a icosahedron
final int numVerticesPerStrip = Maths.power(2, depth) * 3;
final double altitudeStepAngle = Maths.rad120 / Maths.power(2, depth);
final double azimuthStepAngle = Maths.rad360 / this.mTotalNumStrips;
double x, y, z, h, altitude, azimuth;
Log.e("mTotalNumStrips", ""+mTotalNumStrips);
Log.e("numVerticesPerStrip", ""+numVerticesPerStrip);
for (int stripNum = 0; stripNum < this.mTotalNumStrips; stripNum++) {
// Setup arrays to hold the points for this strip.
final float[] vertices = new float[numVerticesPerStrip * 3]; // x,y,z
final float[] texturePoints = new float[numVerticesPerStrip * 2]; // 2d texture
int vertexPos = 0;
int texturePos = 0;
// Calculate position of the first vertex in this strip.
altitude = Maths.rad90;
azimuth = stripNum * azimuthStepAngle;
// Draw the rest of this strip.
for (int vertexNum = 0; vertexNum < numVerticesPerStrip; vertexNum += 2) {
// First point - Vertex.
y = radius * Math.sin(altitude);
h = radius * Math.cos(altitude);
z = h * Math.sin(azimuth);
x = h * Math.cos(azimuth);
vertices[vertexPos++] = (float) x;
vertices[vertexPos++] = (float) y;
vertices[vertexPos++] = (float) z;
// First point - Texture.
texturePoints[texturePos++] = (float) (1 + azimuth / Maths.rad360);
texturePoints[texturePos++] = (float) (1 - (altitude + Maths.rad90) / Maths.rad180);
// Second point - Vertex.
altitude -= altitudeStepAngle;
azimuth -= azimuthStepAngle / 2.0;
y = radius * Math.sin(altitude);
h = radius * Math.cos(altitude);
z = h * Math.sin(azimuth);
x = h * Math.cos(azimuth);
vertices[vertexPos++] = (float) x;
vertices[vertexPos++] = (float) y;
vertices[vertexPos++] = (float) z;
// Second point - Texture.
texturePoints[texturePos++] = (float) (1 + azimuth / Maths.rad360);
texturePoints[texturePos++] = (float) (1 - (altitude + Maths.rad90) / Maths.rad180);
azimuth += azimuthStepAngle;
}
this.mVertices.add(vertices);
this.mTexture.add(texturePoints);
ByteBuffer byteBuffer = ByteBuffer.allocateDirect(numVerticesPerStrip * 3 * Float.SIZE);
byteBuffer.order(ByteOrder.nativeOrder());
FloatBuffer fb = byteBuffer.asFloatBuffer();
fb.put(this.mVertices.get(stripNum));
fb.position(0);
this.mVertexBuffer.add(fb);
// Setup texture.
byteBuffer = ByteBuffer.allocateDirect(numVerticesPerStrip * 2 * Float.SIZE);
byteBuffer.order(ByteOrder.nativeOrder());
fb = byteBuffer.asFloatBuffer();
fb.put(this.mTexture.get(stripNum));
fb.position(0);
this.mTextureBuffer.add(fb);
}
}
public void loadGLTexture(final GL10 gl, final Context context, final int texture) {
Bitmap bitmap = BitmapDecoder.from(context.getResources(), texture)
.scale(4048, 2024)
.decode();
// Generate one texture pointer, and bind it to the texture array.
gl.glGenTextures(1, this.mTextures, 0);
gl.glBindTexture(GL10.GL_TEXTURE_2D, this.mTextures[0]);
// Create nearest filtered texture.
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
// Use Android GLUtils to specify a two-dimensional texture image from our bitmap.
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
// Tide up.
bitmap.recycle();
}
/**
* The draw method for the square with the GL context.
*
* #param gl Graphics handle.
*/
public void draw(final GL10 gl) {
// bind the previously generated texture.
gl.glBindTexture(GL10.GL_TEXTURE_2D, this.mTextures[0]);
// Point to our buffers.
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
// Set the face rotation, clockwise in this case.
gl.glFrontFace(GL10.GL_CW);
// Point to our vertex buffer.
for (int i = 0; i < this.mTotalNumStrips; i++) {
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, this.mVertexBuffer.get(i));
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, this.mTextureBuffer.get(i));
// Draw the vertices as triangle strip.
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, this.mVertices.get(i).length / 3);
}
// Disable the client state before leaving.
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
}
}
And this is my renderer...
#Override
public void onDrawFrame(final GL10 gl) {
zvector = new float[] {0,0,1,0};
resultvector = new float[] {0,0,1,0};
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glLoadIdentity();
float radiansX = (float) Math.toRadians(gyro_angle[1]);
float radiansY = (float) Math.toRadians(-gyro_angle[0]);
float radiansZ = (float) Math.toRadians(-gyro_angle[2]);
// Finds the Sin and Cosin for the half angle.
float sinX =(float) Math.sin(radiansX * 0.5);
float cosX =(float) Math.cos(radiansX * 0.5);
float sinY =(float) Math.sin(radiansY * 0.5);
float cosY =(float) Math.cos(radiansY * 0.5);
float sinZ =(float) Math.sin(radiansZ * 0.5);
float cosZ =(float) Math.cos(radiansZ * 0.5);
// Formula to construct a new Quaternion based on direction and angle.
quatX[0] = cosX;
quatX[1] = 1 * sinX;
quatX[2] = 0 * sinX;
quatX[3] = 0 * sinX;
quatY[0] = cosY;
quatY[1] = 0 * sinY;
quatY[2] = 1 * sinY;
quatY[3] = 0 * sinY;
quatZ[0] = cosZ;
quatZ[1] = 0 * sinZ;
quatZ[2] = 0 * sinZ;
quatZ[3] = 1 * sinZ;
quat1 = multiplyQuat(quatX, quatY);
quat2 = multiplyQuat(quat1, quatZ);
mMatrix = getMatrixfromQuat(quat1);
gl.glLoadMatrixf(mMatrix, 0);
this.mSphere.draw(gl);
}
#Override
public void onSurfaceChanged(final GL10 gl, final int width, final int height) {
final float aspectRatio = (float) width / (float) (height == 0 ? 1 : height);
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
GLU.gluPerspective(gl, 45.0f, aspectRatio, 0.1f, 100.0f);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
}
#Override
public void onSurfaceCreated(final GL10 gl, final EGLConfig config) {
this.mSphere.loadGLTexture(gl, this.mContext, R.drawable.pic360);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glShadeModel(GL10.GL_SMOOTH);
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
gl.glClearDepthf(1.0f);
gl.glEnable(GL10.GL_DEPTH_TEST);
gl.glDepthFunc(GL10.GL_LEQUAL);
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
}
//CONSTRUCTER
public GlRenderer(final Context context) {
this.mContext = context;
this.mSphere = new Sphere(5, 2);
sensorManager = (SensorManager) this.mContext.getSystemService(this.mContext.SENSOR_SERVICE);
sensorGyroscope = sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
sensorAccelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
sensorMagneticField = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
valuesAccelerometer = new float[3];
valuesMagneticField = new float[3];
matrixR = new float[9];
matrixI = new float[9];
matrixValues = new float[3];
sensorManager.registerListener(this, sensorGyroscope, SensorManager.SENSOR_DELAY_FASTEST);
sensorManager.registerListener(this, sensorAccelerometer, SensorManager.SENSOR_DELAY_FASTEST);
sensorManager.registerListener(this, sensorMagneticField, SensorManager.SENSOR_DELAY_FASTEST);
}
//HERE GOES SOME CURRENTLY IRRELEVANT STUFF ABOUT THE SENSORS AND QUATERNIONS
I had some this type of video texturing problem. First time I used ffmpeg for video decoding but the performance was so poor (just like you- Extracting frame by frame). For improving performance I used android default mediaplayer. You can use surface texture to create an opengl surface (sphere, cylinder, cube etc...) and then set the surface in the media player
Surface surface = new Surface(mSurface);//mSurface is your surface texture
mMediaPlayer.setSurface(surface);
mMediaPlayer.setScreenOnWhilePlaying(true);
This is just a technique. I did this for some commercial enclosed project, so I cant share the code. I hope I'll published a free code in github soon.
I am making a 3D game that has a player with the follow cam. Before I started using real models I used the cube and I rendered it using displaylist and it everything moved fine. However, now that I am importing full 3D models with many more vertices, I looked into VBOs. I have a full structure setup for my VBOs and I can see the model drawn initially but it is drawn at the center of the game world. When I move the player, the model doesn't translate as it should. The model doesn't move its position.
Here is the code that I used initially to draw the player as a rectangle (which works):
public static void drawRectPrism(float centerx, float centery, float centerz, float length, float height, float width, float rx, float ry, float rz)
{
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
{
glTranslatef(centerx, centery, centerz);
glRotatef(rx, 1, 0, 0);
glRotatef(ry, 0, 1, 0);
glRotatef(rz, 0, 0, 1);
glTranslatef(-centerx, -centery, -centerz);
glTranslatef(-length/2f, -height/2f, -width/2f);
glBegin(GL_QUADS);
{
glColor3f(1.0f, 0, 0);
glVertex3f(centerx, centery, centerz);
glVertex3f(centerx + length, centery, centerz);
glVertex3f(centerx + length, centery + height, centerz);
glVertex3f(centerx, centery + height, centerz);
glColor3f(0, 1.0f, 0);
glVertex3f(centerx, centery, centerz + width);
glVertex3f(centerx + length, centery, centerz + width);
glVertex3f(centerx + length, centery + height, centerz + width);
glVertex3f(centerx, centery + height, centerz + width);
glColor3f(0, 0, 1.0f);
glVertex3f(centerx, centery, centerz);
glVertex3f(centerx, centery + height, centerz);
glVertex3f(centerx, centery + height, centerz + width);
glVertex3f(centerx, centery, centerz + width);
glColor3f(0, 1.0f, 1.0f);
glVertex3f(centerx + length, centery, centerz);
glVertex3f(centerx + length, centery + height, centerz);
glVertex3f(centerx + length, centery + height, centerz + width);
glVertex3f(centerx + length, centery, centerz + width);
glColor3f(1.0f, 1.0f, 0);
glVertex3f(centerx, centery, centerz);
glVertex3f(centerx + length, centery, centerz);
glVertex3f(centerx + length, centery, centerz + width);
glVertex3f(centerx, centery, centerz + width);
glColor3f(1.0f, 0, 1.0f);
glVertex3f(centerx, centery + height, centerz);
glVertex3f(centerx + length, centery + height, centerz);
glVertex3f(centerx + length, centery + height, centerz + width);
glVertex3f(centerx, centery + height, centerz + width);
}
glEnd();
}
glPopMatrix();
}
I tried a couple of different ways somewhere better than others and probably implemented terrible programming structure, but I figured it should still work.
First attempt: to adapt the rectangle code to load my vertices and models instead of specific rectangle verticies:
public void translate(float x, float y, float z, float rx, float ry, float rz)
{
File f = new File("graveDigga.obj");
try{
m = OBJLoader.loadModel(f);
}
catch(FileNotFoundException e)
{
e.printStackTrace();
Display.destroy();
System.exit(1);
}
catch(IOException e)
{
e.printStackTrace();
Display.destroy();
System.exit(1);
}
displayListChar = glGenLists(1);
glNewList(displayListChar, GL_COMPILE);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
{
glTranslatef(x, y, z);
glRotatef(rx, 1, 0, 0);
glRotatef(ry, 0, 1, 0);
glRotatef(rz, 0, 0, 1);
//glTranslatef(-x, -y, -z);
//glTranslatef(-length/2f, -height/2f, -width/2f);
glBegin(GL_TRIANGLES);
for(Face face : m.faces)
{
Vector2f t1 = m.textures.get((int) face.textures.x - 1);
glTexCoord2f(t1.x +x ,1-(t1.y +y ));
Vector3f n1 = m.normals.get((int) face.normal.x-1);
glNormal3f(n1.x +x ,n1.y+y,n1.z +z);
Vector3f v1 = m.vertices.get((int) face.vertex.x-1);
glVertex3f(v1.x +x,v1.y+y,v1.z+z);
Vector2f t2 = m.textures.get((int) face.textures.y - 1);
glTexCoord2f(t2.x +x, 1 - (t2.y+y ));
Vector3f n2 = m.normals.get((int) face.normal.y-1);
glNormal3f(n2.x+x,n2.y+y ,n2.z+z);
Vector3f v2 = m.vertices.get((int) face.vertex.y-1);
glVertex3f(v2.x+x,v2.y+y ,v2.z+z);
Vector2f t3 = m.textures.get((int) face.textures.z - 1);
glTexCoord2f(t3.x +x, 1 - (t3.y +y));
Vector3f n3 = m.normals.get((int) face.normal.z-1);
glNormal3f(n3.x+x,n3.y+y,n3.z +z);
Vector3f v3 = m.vertices.get((int) face.vertex.z-1);
glVertex3f(v3.x+x,v3.y+y,v3.z +z);
}
glEnd();
}
glPopMatrix();
//}
//glPopMatrix();
build();
}
I next tried to display model by creating a VBO from this data and call a rander method in my game loop. Before calling render I would run through the code to attempt to translate the position of VBO but nothing was happening.
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
{
//glLoadIdentity();
glTranslatef(x,y,z);
glRotatef(rx, 1, 0, 0);
glRotatef(ry, 0, 1, 0);
glRotatef(rz, 0, 0, 1);
glTranslatef(-x,-y,-z);
glDrawArrays(GL_TRIANGLES, 0, m.faces.size() * 3);
}
I am not sure if I should be using shaders for this or not, but part of me is questioning why it is hard to move a 3D model in world space? Is there a messy way that is easier to implement for a temporary basis?
Considering you're a new person with 1 rep, have an upvote. Nicely written question :).
I am not sure if I should be using shaders for this or not, but part of me is questioning why it is hard to move a 3D model in world space? Is there a messy way that is easier to implement for a temporary basis?
A simple glTranslatef() call should suffice to move an object, and simple glRotatef() call will rotate the object.
For example, using glRotatef(90, 1, 0, 0) returns this result:
Wheras without the line, the grass is not rotated at all:
Same with the ship. Using glRotatef(40, -1, 0, 0) returns this result:
Wheras without the line it just returns flat:
Obviously that is just the pitch. glRotatef(AmountToRotate, PITCH, YAW, ROLL) can roll the ship onto its side, or rotate the ship around.
Enough about rotation.
For rendering the grass, I just use this:
public void render(){
Main.TerrainDemo.shader.start();
glPushMatrix();
glDisable(GL_LIGHTING);
glTranslatef(location.x * TerrainDemo.scale, location.y, location.z * TerrainDemo.scale);
TexturedModel texturedModel = TerrainDemo.texModel;
RawModel model = texturedModel.getRawModel();
GL30.glBindVertexArray(model.getVaoID());
GL20.glEnableVertexAttribArray(0);
GL20.glEnableVertexAttribArray(1);
GL13.glActiveTexture(GL13.GL_TEXTURE0);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, texturedModel.getTexture().getID());
glScalef(10f, 10f, 10f);
glColor4f(0, 0, 0, 0.5f);
glDrawElements(GL_TRIANGLES, model.getVertexCount(), GL11.GL_UNSIGNED_INT, 0);
GL20.glDisableVertexAttribArray(0);
GL20.glDisableVertexAttribArray(1);
GL30.glBindVertexArray(0);
glEnable(GL_LIGHTING);
glPopMatrix();
Main.TerrainDemo.shader.stop();
}
To cut through code which you will probably not recognize/understand, I am basically just saying that glTranslatef(location.x * TerrainDemo.scale, location.y, location.z * TerrainDemo.scale) is the only thing that is setting the location. After translating, I simple set the scale (the size), and then draw it.
Wheras if I remove the glTranslatef() line, all the grass will just render in the same location:
So to answer your question:
use something like this (Psuedocode)
PUSH MATRIX HERE (glPushMatrix) SO TO NOT SAVE THE CURRENT TRANSLATION
USE GLTRANSLATEF ON LOCATION OF CURRENT OBJECT
RENDER/DRAW OBJECT
POP THE MATRIX
Unfortunately, looking through your code I could'nt find the specific issue that is actually causing it not to draw, meaning I cannot just say "Have xxx code and it will work", but I hope that it helped on how to move/rotate an object.
I am using VBOs just like you are for rendering the grass, ship, and trees (though I use a display list for terrain because I am lazy).
My skype is joehot200 if you wish to discuss anything further.
I've spent days searching, trying tutorials, and not actually getting results in this, so here I am.
I'm trying, simply put, to animate a collection of objects (Android Studio) on the screen, in a 2D format, with each independent movements and rotations. However, when I try this, I'm either not getting the object rendered, or its rendering skewed (as if rotated through the vertical Y-axis)
I know the importance of the order in which objects are drawn too (to give correct Z-ordering appearance) however, I'm at a bit of a loss with the matrix manipulation.
Here is what I have so far:
Main Activity - standard stuff
private GLSurfaceView mGLSurfaceView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mGLSurfaceView = new GLSurfaceView(this);
//check if device supports ES 2.0
final ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
final ConfigurationInfo configurationInfo = activityManager.getDeviceConfigurationInfo();
final boolean supportsEs2 = configurationInfo.reqGlEsVersion >= 0x20000;
if (supportsEs2) {
//Get the ES2 compatible context
mGLSurfaceView.setEGLContextClientVersion(2);
//set renderer to my renderer below
mGLSurfaceView.setRenderer(new MyGL20Renderer(this));
} else {
//no support
return;
}
//setContentView(R.layout.activity_main);
setContentView(mGLSurfaceView);
}
GL20Renderer class - Notice I'm now just manually adding 2 objects to my collection to render
public class MyGL20Renderer implements GLSurfaceView.Renderer
{
private final Context mActivityContext;
//Matrix Initializations
private final float[] mMVPMatrix = new float[16];
private final float[] mProjMatrix = new float[16];
private final float[] mVMatrix = new float[16];
private float[] mRotationMatrix = new float[16];
private final float[] mRotateMatrix = new float[16];
private final float[] mMoveMatrix = new float[16];
private final float[] mTempMatrix = new float[16];
private final float[] mModelMatrix = new float[16];
private int numObjects = 2;
private ArrayList<Sprite> spriteList = new ArrayList<Sprite>();
//Declare as volatile because we are updating it from another thread
public volatile float mAngle;
//private Triangle triangle;
//private Sprite sprite;
public MyGL20Renderer(final Context activityContext)
{
mActivityContext = activityContext;
}
public void onSurfaceCreated(GL10 unused, EGLConfig config)
{
//Set the background frame color
GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
//Set the camera position (View Matrix) //mtx, offset, eyex,y,z, centrex,y,z, upx,y,z
Matrix.setLookAtM(mVMatrix, 0,
0, 0, -1.5f, //Eye XYZ - position eye behind the origin
0f, 0f, -5.0f, //Look XYZ - We are looking toward the distance
0f, 1.0f, 0.0f); //Up XYZ - Up vector - where head would be pointing if holding the camera
//Initialize Shapes
//triangle = new Triangle();
//sprite = new Sprite(mActivityContext);
//Sprite newSprite;
float xMax = 2.0f;
float yMax = 2.0f;
//rand = 0->1
float newX = (new Random().nextFloat() * xMax * 2) - xMax; //2.0f; //-2 -> +2
float newY = (new Random().nextFloat() * yMax * 2) - yMax; //-3 -> +3
float newZ = 0f;
//for (int i=0; i<numObjects; i++) {
//newSprite = new Sprite(mActivityContext);
//spriteList.add(new Sprite(mActivityContext, newX, newY, newZ));
//}
spriteList.add(new Sprite(mActivityContext, -0.0f, -0.0f, 0.0f));
spriteList.add(new Sprite(mActivityContext, +0.5f, -0.5f, 0.0f));
//spriteList.add(new Sprite(mActivityContext, -1.0f, +1.0f, 0.0f));
//spriteList.add(new Sprite(mActivityContext, +1.0f, +1.0f, 0.0f));
}
public void onDrawFrame(GL10 unused)
{
//init
Sprite currSprite;
//Redraw background color
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
//timing
float jFactor = 0.1f;
long time = SystemClock.uptimeMillis() % 10000L;
float angleInDegrees = (360.0f / 1000.0f) * ((int) time) * jFactor;
/*
//number 1
//Matrix.setIdentityM(mModelMatrix, 0);
//currSprite = spriteList.get(0);
//Matrix.rotateM(mModelMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
//currSprite.Draw(mModelMatrix);
//number 2
Matrix.setIdentityM(mModelMatrix, 0);
currSprite = spriteList.get(1);
Matrix.translateM(mModelMatrix, 0, 0.0f, -0.1f, 0.0f);
//Matrix.rotateM(mModelMatrix, 0, 90.0f, 1.0f, 0.0f, 0.0f);
Matrix.rotateM(mModelMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
currSprite.Draw(mModelMatrix);
//Matrix.translateM(mModelMatrix, 0, 0, 0, 4.0f);
*/
//Calculate the projection and view transformation
Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
//zoom out a bit?
Matrix.translateM(mMVPMatrix, 0, 0, 0, 4.0f);
//number 1
//currSprite = spriteList.get(0);
//Matrix.setIdentityM(mMVPMatrix, 0);
//Matrix.rotateM(mMVPMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
//Matrix.translateM(mMVPMatrix, 0, currSprite.coordX, 0.0f, 0.0f);
//currSprite.coordX += 0.01f;
//currSprite.Draw(mMVPMatrix);
//number 2
currSprite = spriteList.get(0);
Matrix.setIdentityM(mMVPMatrix, 0);
Matrix.translateM(mMVPMatrix, 0, 0.0f, 0.0f, 0.0f);
Matrix.rotateM(mMVPMatrix, 0, angleInDegrees, 0.0f, 0.0f, +1.0f);
//float[] mTempMatrix = new float[16];
//mTempMatrix = mModelMatrix.clone();
//Matrix.multiplyMM(mMVPMatrix, 0, mMVPMatrix, 0, mRotateMatrix, 0);
//mTempMatrix = mMVPMatrix.clone();
//Matrix.multiplyMM(mMVPMatrix, 0, mTempMatrix, 0, mModelMatrix, 0);
//Matrix.setIdentityM(mMVPMatrix, 0);
currSprite.Draw(mMVPMatrix);
/*
//Set the camera position (View Matrix) //mtx, offset, eyex,y,z, centrex,y,z, upx,y,z
Matrix.setLookAtM(mVMatrix, 0,
0, 0, -10,
0f, 0f, 0f,
0f, 1.0f, 0.0f);
//Calculate the projection and view transformation
Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
//zoom out a bit?
Matrix.translateM(mMVPMatrix, 0, 0, 0, 4.0f);
for (int i=0; i<numObjects; i++) {
//Create a rotation transformation for the triangle
//Matrix.setRotateM(mRotationMatrix, 0, mAngle, 0, 0, -1.0f);
Matrix.setRotateM(mRotationMatrix, 0, 0, 0, 0, -1.0f); //-1.0 = Z, for some reason need this. Grr
//Combine the rotation matrix with the projection and camera view
Matrix.multiplyMM(mMVPMatrix, 0, mRotationMatrix, 0, mMVPMatrix, 0);
//Draw Shape
//triangle.Draw(mMVPMatrix);
//sprite.Draw(mMVPMatrix);
currSprite = spriteList.get(i);
//Move the object to the passed initial coordinates?
//Matrix.translateM(mMVPMatrix, 0, currSprite.coordX, currSprite.coordY, currSprite.coordZ);
currSprite.Draw(mMVPMatrix);
}
*/
}
public void onSurfaceChanged(GL10 unused, int width, int height)
{
GLES20.glViewport(0, 0, width, height);
if (height == 0) {
height = 1; //incase of div 0 errors
}
float ratio = (float) width / height;
final float left = -ratio;
final float right = ratio;
final float bottom = -1.0f;
final float top = 1.0f;
final float near = 1.0f;
final float far = 10.f;
//This Projection Matrix is applied to object coordinates in the onDrawFrame() method
//Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7);
Matrix.frustumM(mProjMatrix, 0, left, right, bottom, top, near, far);
}
public static int loadShader(int type, String shaderCode)
{
//Create a Vertex Shader Type Or a Fragment Shader Type (GLES20.GL_VERTEX_SHADER OR GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
//Add The Source Code and Compile it
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
}
Please excuse the commented code in OnDrawFrame() where I've been experimenting, and failing.
Sprite Class
public class Sprite
{
//Reference to Activity Context
private final Context mActivityContext;
//Added for Textures
private final FloatBuffer mCubeTextureCoordinates;
private int mTextureUniformHandle;
private int mTextureCoordinateHandle;
private final int mTextureCoordinateDataSize = 2;
private int mTextureDataHandle;
private final String vertexShaderCode =
//Test
"attribute vec2 a_TexCoordinate;" +
"varying vec2 v_TexCoordinate;" +
//End Test
"uniform mat4 uMVPMatrix;" +
"attribute vec4 vPosition;" +
"void main() {" +
" gl_Position = vPosition * uMVPMatrix;" +
//Test
"v_TexCoordinate = a_TexCoordinate;" +
//End Test
"}";
private final String fragmentShaderCode =
"precision mediump float;" +
"uniform vec4 vColor;" +
//Test
"uniform sampler2D u_Texture;" +
"varying vec2 v_TexCoordinate;" +
//End Test
"void main() {" +
//"gl_FragColor = vColor;" +
"gl_FragColor = (vColor * texture2D(u_Texture, v_TexCoordinate));" +
"}";
private final int shaderProgram;
private final FloatBuffer vertexBuffer;
private final ShortBuffer drawListBuffer;
private int mPositionHandle;
private int mColorHandle;
private int mMVPMatrixHandle;
public float coordX;
public float coordY;
//public float coordZ;
// number of coordinates per vertex in this array
static final int COORDS_PER_VERTEX = 2;
static float spriteCoords[] = { -0.5f, 0.5f, // top left
-0.5f, -0.5f, // bottom left
0.5f, -0.5f, // bottom right
0.5f, 0.5f }; //top right
private short drawOrder[] = { 0, 1, 2, 0, 2, 3 }; //Order to draw vertices
private final int vertexStride = COORDS_PER_VERTEX * 4; //Bytes per vertex
// Set color with red, green, blue and alpha (opacity) values
//float color[] = { 0.63671875f, 0.76953125f, 0.22265625f, 1.0f };
float color[] = { 1f, 1f, 1f, 1.0f };
public Sprite(final Context activityContext, float initX, float initY, float initZ)
{
mActivityContext = activityContext;
this.coordX = initX;
this.coordY = initY;
//this.coordZ = initZ;
//ergh - will do manually for now. Paxo n00b
//just a 2D array, no need for Z nonsense
for (int i=0; i<spriteCoords.length; i++) {
spriteCoords[i] -= (i%2==0) ? coordX : coordY; //- works better than +
}
//float newPosMatrix[] = { initX, initY, 0f };
//adjust the vector coords accordingly
//Matrix.multiplyMV(spriteCoords, 0, newPosMatrix, 0, spriteCoords, 0);
//Initialize Vertex Byte Buffer for Shape Coordinates / # of coordinate values * 4 bytes per float
ByteBuffer bb = ByteBuffer.allocateDirect(spriteCoords.length * 4);
//Use the Device's Native Byte Order
bb.order(ByteOrder.nativeOrder());
//Create a floating point buffer from the ByteBuffer
vertexBuffer = bb.asFloatBuffer();
//Add the coordinates to the FloatBuffer
vertexBuffer.put(spriteCoords);
//Set the Buffer to Read the first coordinate
vertexBuffer.position(0);
// S, T (or X, Y)
// Texture coordinate data.
// Because images have a Y axis pointing downward (values increase as you move down the image) while
// OpenGL has a Y axis pointing upward, we adjust for that here by flipping the Y axis.
// What's more is that the texture coordinates are the same for every face.
final float[] cubeTextureCoordinateData =
{
//Front face
/*0.0f, 0.0f,
0.0f, 1.0f,
1.0f, 0.0f,
0.0f, 1.0f,
1.0f, 1.0f,
1.0f, 0.0f*/
/*-0.5f, 0.5f,
-0.5f, -0.5f,
0.5f, -0.5f,
0.5f, 0.5f*/
0f, 1f,
0f, 0f,
1f, 0f,
1f, 1f
};
mCubeTextureCoordinates = ByteBuffer.allocateDirect(cubeTextureCoordinateData.length * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
mCubeTextureCoordinates.put(cubeTextureCoordinateData).position(0);
//Initialize byte buffer for the draw list
ByteBuffer dlb = ByteBuffer.allocateDirect(spriteCoords.length * 2);
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(drawOrder);
drawListBuffer.position(0);
int vertexShader = MyGL20Renderer.loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = MyGL20Renderer.loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);
shaderProgram = GLES20.glCreateProgram();
GLES20.glAttachShader(shaderProgram, vertexShader);
GLES20.glAttachShader(shaderProgram, fragmentShader);
//Texture Code
GLES20.glBindAttribLocation(shaderProgram, 0, "a_TexCoordinate");
GLES20.glLinkProgram(shaderProgram);
//Load the texture
mTextureDataHandle = loadTexture(mActivityContext, R.drawable.cube);
}
public void Draw(float[] mvpMatrix)
{
//Add program to OpenGL ES Environment
GLES20.glUseProgram(shaderProgram);
//Get handle to vertex shader's vPosition member
mPositionHandle = GLES20.glGetAttribLocation(shaderProgram, "vPosition");
//Enable a handle to the triangle vertices
GLES20.glEnableVertexAttribArray(mPositionHandle);
//Prepare the triangle coordinate data
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);
//Get Handle to Fragment Shader's vColor member
mColorHandle = GLES20.glGetUniformLocation(shaderProgram, "vColor");
//Set the Color for drawing the triangle
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
//Set Texture Handles and bind Texture
mTextureUniformHandle = GLES20.glGetAttribLocation(shaderProgram, "u_Texture");
mTextureCoordinateHandle = GLES20.glGetAttribLocation(shaderProgram, "a_TexCoordinate");
//Set the active texture unit to texture unit 0.
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
//Bind the texture to this unit.
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureDataHandle);
//Tell the texture uniform sampler to use this texture in the shader by binding to texture unit 0.
GLES20.glUniform1i(mTextureUniformHandle, 0);
//Pass in the texture coordinate information
mCubeTextureCoordinates.position(0);
GLES20.glVertexAttribPointer(mTextureCoordinateHandle, mTextureCoordinateDataSize, GLES20.GL_FLOAT, false, 0, mCubeTextureCoordinates);
GLES20.glEnableVertexAttribArray(mTextureCoordinateHandle);
//Get Handle to Shape's Transformation Matrix
mMVPMatrixHandle = GLES20.glGetUniformLocation(shaderProgram, "uMVPMatrix");
//Apply the projection and view transformation
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0);
//glTranslatef(0f, 0f, 0f);
//Draw the triangle
GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
//Disable Vertex Array
GLES20.glDisableVertexAttribArray(mPositionHandle);
}
public static int loadTexture(final Context context, final int resourceId)
{
final int[] textureHandle = new int[1];
GLES20.glGenTextures(1, textureHandle, 0);
if (textureHandle[0] != 0)
{
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = false; // No pre-scaling
// Read in the resource
final Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resourceId, options);
// Bind to the texture in OpenGL
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]);
// Set filtering
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);
// Load the bitmap into the bound texture.
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
// Recycle the bitmap, since its data has been loaded into OpenGL.
bitmap.recycle();
}
if (textureHandle[0] == 0)
{
throw new RuntimeException("Error loading texture.");
}
return textureHandle[0];
}
}
Now, I don't know if I'm going about this the right way at all, but I simply want to just animate the collection of Sprite objects in spriteList.
More specifically, have a collection of 3 objects and then respond to screen touch, and animate the objects to that location (but that will come later)
Initially, I just want to be able to correctly render these objects (with initial locations) and then rotate them on the centre point (about the Z axis).
For some reason, TranslateM is warping the texture (as if about the Y axis) and not actually moving an object along the X/Y planes
Many thanks for any help you can offer. As you can see I'm fairly new to OpenGL and have had little luck with the limited tutorials out there that support Android Studio and GLES2.0.
Kind regards,
James
I think the problem is that you have not multiplied the translation matrices into your rotation matrices. A matrix multiply is required to combine those.