This tutorial shows you how to create a simple Android application that uses OpenGL ES 1.0 and -perform some basic operations using the OpenGL ES 1.0 API, including:
- -This tutorial demonstrates use of the OpenGL ES 1.0 API. Both the OpenGL ES 1.0 and the ES 1.1 -API are supported by the Android framework since release 1.0 (API Level 1). The OpenGL ES 1.1 API -is an extention of the 1.0 API, and it's capabilities are beyond the scope of this tutorial.
- -Beginning with Android 2.2 (API Level 8), the framework supports OpenGL ES 2.0. For more -information about compatibility for OpenGL versions and Android devices, see the 3D with OpenGL document.
- - -OpenGL applications for Android have the same basic structure as other applications, however -OpenGL applications use {@link android.opengl.GLSurfaceView} where other, non-OpenGL -applications use the {@link android.view.View} or {@link android.view.SurfaceView} class.
- -
To get started using OpenGL in your Android application, you must implement both a {@link -android.opengl.GLSurfaceView} and a {@link android.opengl.GLSurfaceView.Renderer}. The {@link -android.opengl.GLSurfaceView} is the main view type for the OpenGL applications and the {@link -android.opengl.GLSurfaceView.Renderer} controls what is drawn within that view. For more -information about these classes, see the 3D -with OpenGL document.
- -To create an application that uses OpenGL ES 1.0:
- -HelloOpenGLES10.
-
- Note: If you have not created a basic Android application yet, follow the - Hello World Tutorial instructions - to familiarize yourself with the process.
-HelloOpenGLES10 class as follows:
-
-package com.example.android.apis.graphics;
-
-import android.app.Activity;
-import android.content.Context;
-import android.opengl.GLSurfaceView;
-import android.os.Bundle;
-
-public class HelloOpenGLES10 extends Activity {
-
- private GLSurfaceView mGLView;
-
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
-
- mGLView = new HelloOpenGLSurfaceView(this);
- setContentView(mGLView);
- }
-
- @Override
- protected void onPause() {
- super.onPause();
- mGLView.onPause();
- }
-
- @Override
- protected void onResume() {
- super.onResume();
- mGLView.onResume();
- }
-
-}
-
-class HelloOpenGLES10SurfaceView extends GLSurfaceView {
-
- public HelloOpenGLES10SurfaceView(Context context){
- super(context);
- setRenderer(new HelloOpenGLES10Renderer());
- }
-
-}
-
- This Activity class creates a basic container for a {@link android.opengl.GLSurfaceView}.
-HelloOpenGLES10Renderer, which implements the
- {@link android.opengl.GLSurfaceView.Renderer} interface:
-
-
-package com.example.android.apis.graphics;
-
-import javax.microedition.khronos.egl.EGLConfig;
-import javax.microedition.khronos.opengles.GL10;
-
-import android.opengl.GLSurfaceView;
-
-public class HelloOpenGLES10Renderer implements GLSurfaceView.Renderer {
-
- public void onSurfaceCreated(GL10 gl, EGLConfig config) {
- // Set the background frame color
- gl.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
- }
-
- public void onDrawFrame(GL10 gl) {
- // Redraw background color
- gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
- }
-
- public void onSurfaceChanged(GL10 gl, int width, int height) {
- gl.glViewport(0, 0, width, height);
- }
-
-}
-
- These classes create a simple Android application which displays a grey screen using OpenGL -ES 1.0 calls. While this application does not do anything very interesting, by creating these two -classes, you have layed the foundation needed to start drawing graphic elements with OpenGL ES -1.0.
- -If you are familiar with the OpenGL ES APIs, these two classes should give you enough information -to start using the OpenGL ES 1.0 API and creating graphics. However, if you need a bit more help -getting started with OpenGL, head on to the next sections for a few more tips.
- -Once you have implemented a {@link android.opengl.GLSurfaceView.Renderer}, the next step is to -draw something on it. This section shows you how to define and draw a basic triangle shape with the -Android OpenGL ES 1.0 API.
- -Note: The following instructions build on the previous section, so if you -have not been following along, go back to the previous section and catch -up.
- -OpenGL allows you to define objects using coordinates in three-dimensional space. So, before you - can draw a triangle, you must define its coordinates. In OpenGL, the typical way to do this is to - define a vertex array for the coordinates.
- -By default, OpenGL ES assumes a coordinate system where 0,0,0 (X,Y,Z) specifies the center of - the {@link android.opengl.GLSurfaceView} frame, 1,1,0 is the top right corner of the frame and --1,-1,0 is bottom left corner of the frame.
- -To define a vertex array for a triangle:
- -HelloOpenGLES10Renderer class, add new member variable to contain the
-vertices of a triangle shape:
-- private FloatBuffer triangleVB; --
initShapes() which populates this member variable:
-
- private void initShapes(){
-
- float triangleCoords[] = {
- // X, Y, Z
- -0.5f, -0.25f, 0,
- 0.5f, -0.25f, 0,
- 0.0f, 0.559016994f, 0
- };
-
- // initialize vertex Buffer for triangle
- ByteBuffer vbb = ByteBuffer.allocateDirect(
- // (# of coordinate values * 4 bytes per float)
- triangleCoords.length * 4);
- vbb.order(ByteOrder.nativeOrder());
- triangleVB = vbb.asFloatBuffer();
- triangleVB.put(triangleCoords);
- triangleVB.position(0);
-
- }
-
- This method defines a two-dimensional triangle shape with three equal sides.
-onSurfaceCreated() method to initialize your triangle:
-
- public void onSurfaceCreated(GL10 gl, EGLConfig config) {
-
- // Set the background frame color
- gl.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
-
- // initialize the triangle vertex array
- initShapes();
- }
-
- Warning: Shapes and other static objects should be initialized
- once in your onSurfaceCreated() method for best performance. Avoid initializing the
- new objects in onDrawFrame(), as this causes the system to re-create the objects
- for every frame redraw and slows down your application.
-
Now that you have defined a shape to draw, you can use the OpenGL APIs to draw the -object.
- -To draw the triangle with OpenGL:
- -onSurfaceCreated() method to enable vertex arrays.
-
- public void onSurfaceCreated(GL10 gl, EGLConfig config) {
-
- // Set the background frame color
- gl.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
-
- // initialize the triangle vertex array
- initShapes();
-
- // Enable use of vertex arrays
- gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
- }
-
- At this point, you are ready to draw the triangle object in the OpenGL frame.
-onDrawFrame() method to draw the triangle.
-
- public void onDrawFrame(GL10 gl) {
- // Redraw background color
- gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
-
- // Draw the triangle
- gl.glColor4f(0.63671875f, 0.76953125f, 0.22265625f, 0.0f);
- gl.glVertexPointer(3, GL10.GL_FLOAT, 0, triangleVB);
- gl.glDrawArrays(GL10.GL_TRIANGLES, 0, 3);
- }
-
- Note: Since the triangle is stationary at this point, the system is redrawing the - object repeatedly in exactly the same place and so is not the most efficient use of the OpenGL - graphics pipeline. In a later section, we add motion to the object to - justify this use of processing power.
-Try running this example application on your emulator or test device and -you should see something like this:
- -
-
-There are a few problems with this example. First of all, it's not going to impress your -friends. Secondly, the triangle is a bit squashed and changes shape when you change the screen -orientation of the test device. The reason the shape is skewed is due to the fact that the object is -being rendered in a frame which is not perfectly square. We fix that problem in the -next section.
- -OpenGL Projection and Views provide a way to calculate the coordinates of graphic objects in -realistic proportions on graphics displays of any size. One of the basic problems in displaying -graphics is that Android device displays are typically not square and—by default—OpenGL -happily maps a perfectly square, uniform coordinate system onto your typically non-square -screen.
- -
-
-The illustration above shows the uniform coordinate system assumed for an OpenGL frame on the - left, and how these coordinates actually map to a typical device screen in landscape orientation - on the right. To solve this problem, you can apply OpenGL projection modes and views to transform - object coordinates so your graphic objects have the correct proportions on any display.
- -To use a projection transformation on your triangle:
-onSurfaceChanged() method to enable {@link
- javax.microedition.khronos.opengles.GL10#GL_PROJECTION GL10.GL_PROJECTION} mode, calculate the
- screen ratio and apply the ratio as a transformation of the object coordinates.
-
- public void onSurfaceChanged(GL10 gl, int width, int height) {
- gl.glViewport(0, 0, width, height);
-
- // make adjustments for screen ratio
- float ratio = (float) width / height;
- gl.glMatrixMode(GL10.GL_PROJECTION);
- gl.glLoadIdentity();
- gl.glFrustumf(-ratio, ratio, -1, 1, 3, 7);
- }
-
- onDrawFrame() method to apply the {@link
-javax.microedition.khronos.opengles.GL10#GL_MODELVIEW GL_MODELVIEW} mode and set
-a view point for the display using {@link
-android.opengl.GLU#gluLookAt(javax.microedition.khronos.opengles.GL10, float, float, float, float,
-float, float, float, float, float) GLU#gluLookAt()}.
-
- public void onDrawFrame(GL10 gl) {
- // Redraw background color
- gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
-
- // Set GL_MODELVIEW transformation mode
- gl.glMatrixMode(GL10.GL_MODELVIEW);
- gl.glLoadIdentity();
-
- // When using GL_MODELVIEW, you must set the view point
- GLU.gluLookAt(gl, 0, 0, -5, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
-
- // Draw the triangle
- ...
- }
-
- Try running this updated application on your emulator or test device and you should see something -like this:
- -
-
-Now that you have applied this transformation, the triangle has three equal sides, instead of the -squashed display in the earlier version.
- -While it may be interesting exercise to create static graphic objects with OpenGL ES, chances -are you want at least some of your objects to move. In this section, we add motion to to our -triangle by rotating it.
- -To add rotation to your triangle:
-onDrawFrame() method to rotate the triangle object:
-
- public void onDrawFrame(GL10 gl) {
- ...
- // When using GL_MODELVIEW, you must set the view point
- GLU.gluLookAt(gl, 0, 0, -5, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
-
- // Create a rotation for the triangle
- long time = SystemClock.uptimeMillis() % 4000L;
- float angle = 0.090f * ((int) time);
- gl.glRotatef(angle, 0.0f, 0.0f, 1.0f);
-
- // Draw the triangle
- ...
- }
-
- Run the application with this code and your triangle should rotate around its center.
- - - -Be sure to check out the OpenGL ES code samples are available in the -API -Demos sample application and listed in Related Samples -sidebar above. -
diff --git a/docs/html/resources/tutorials/opengl/opengl-es20.jd b/docs/html/resources/tutorials/opengl/opengl-es20.jd deleted file mode 100644 index 5cdc3430fd416..0000000000000 --- a/docs/html/resources/tutorials/opengl/opengl-es20.jd +++ /dev/null @@ -1,514 +0,0 @@ -page.title=Hello OpenGL ES 1.0 -parent.title=Tutorials -parent.link=../../browser.html?tag=tutorial -@jd:body - - -This tutorial shows you how to create a simple Android application that uses OpenGL ES 2.0 and -perform some basic operations using the OpenGL ES 2.0 API, including:
- -This tutorial demonstrates use of the OpenGL ES 2.0 API. Beginning with Android 2.2 (API Level -8), the framework supports OpenGL ES 2.0.
- -Both the OpenGL ES 1.0 and the ES 1.1 API are supported by the Android framework since release -1.0 (API Level 1).For more information about compatibility for OpenGL versions and Android devices, -see the 3D with OpenGL -document.
- - -OpenGL applications for Android have the same basic structure as other applications, however -OpenGL applications use {@link android.opengl.GLSurfaceView} where other, non-OpenGL -applications use the {@link android.view.View} or {@link android.view.SurfaceView} class.
- -
To get started using OpenGL in your Android application, you must implement both a {@link -android.opengl.GLSurfaceView} and a {@link android.opengl.GLSurfaceView.Renderer}. The {@link -android.opengl.GLSurfaceView} is the main view type for the OpenGL applications and the {@link -android.opengl.GLSurfaceView.Renderer} controls what is drawn within that view. For more -information about these classes, see the 3D -with OpenGL document.
- -To create an application that uses OpenGL ES 2.0:
- -HelloOpenGLES20.
-
- Note: If you have not created a basic Android application yet, follow the - Hello World Tutorial instructions - to familiarize yourself with the process.
-HelloOpenGLES20 class as follows:
-
-package com.example.android.apis.graphics;
-
-import android.app.Activity;
-import android.content.Context;
-import android.opengl.GLSurfaceView;
-import android.os.Bundle;
-
-public class HelloOpenGLES20 extends Activity {
-
- private GLSurfaceView mGLView;
-
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
-
- mGLView = new HelloOpenGLES20SurfaceView(this);
- setContentView(mGLView);
- }
-
- @Override
- protected void onPause() {
- super.onPause();
- mGLView.onPause();
- }
-
- @Override
- protected void onResume() {
- super.onResume();
- mGLView.onResume();
- }
-}
-
-class HelloOpenGLES20SurfaceView extends GLSurfaceView {
-
- public HelloOpenGLES20SurfaceView(Context context){
- super(context);
-
- // Create an OpenGL ES 2.0 context.
- setEGLContextClientVersion(2);
-
- setRenderer(new HelloOpenGLES20Renderer());
- }
-}
-
- This Activity class creates a basic container for a {@link android.opengl.GLSurfaceView}.
-HelloOpenGLES20Renderer, which implements the
- {@link android.opengl.GLSurfaceView.Renderer} interface:
-
-
-package com.example.android.apis.graphics;
-
-import javax.microedition.khronos.egl.EGLConfig;
-import javax.microedition.khronos.opengles.GL10;
-
-import android.opengl.GLES20;
-import android.opengl.GLSurfaceView;
-
-public class HelloOpenGLES20Renderer implements GLSurfaceView.Renderer {
-
- public void onSurfaceCreated(GL10 unused, EGLConfig config) {
-
- // Set the background frame color
- GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
- }
-
- public void onDrawFrame(GL10 unused) {
-
- // Redraw background color
- GLES20.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
- }
-
- public void onSurfaceChanged(GL10 unused, int width, int height) {
- GLES20.glViewport(0, 0, width, height);
- }
-
-}
-
- These classes create a simple Android application which displays a grey screen using OpenGL -ES 2.0 calls. While this application does not do anything very interesting, by creating these two -classes, you have layed the foundation needed to start drawing graphic elements with OpenGL ES -2.0.
- -If your application only supports OpenGL ES 2.0, then you should declare that your application - requires OpenGL ES 2.0 by adding the following settings to your AndroidManifest.xml file as -shown below.
- --... - </application> - - <!-- Tell the system that you need ES 2.0. --> - <uses-feature android:glEsVersion="0x00020000" android:required="true" /> - -</manifest> -- -
Adding this declaration hides your application from devices that do not support OpenGL ES 2.0 -in the Android Market.
- -If you are familiar with the OpenGL ES APIs, these preceding classes and the AndroidManifest.xml -declaration should give you enough information to start using the OpenGL ES API and creating -graphics. However, if you need a bit more help getting started with OpenGL, head on to the next -sections for a few more tips.
- - -Once you have implemented a {@link android.opengl.GLSurfaceView.Renderer}, the next step is to -draw something on it. This section shows you how to define and draw a basic triangle shape with the -OpenGL ES 2.0 API.
- -Note: The following instructions build on the previous section, so if you -have not been following along, go back to the previous section and catch -up.
- -OpenGL allows you to define objects using coordinates in three-dimensional space. So, before you - can draw a triangle, you must define its coordinates. In OpenGL, the typical way to do this is to - define a vertex array for the coordinates.
- -By default, OpenGL ES assumes a coordinate system where 0,0,0 (X,Y,Z) specifies the center of - the {@link android.opengl.GLSurfaceView} frame, 1,1,0 is the top right corner of the frame and --1,-1,0 is bottom left corner of the frame.
- -To define a vertex array for a triangle:
- -HelloOpenGLES20Renderer class, add new member variable to contain the
-vertices of a triangle shape:
-- private FloatBuffer triangleVB; --
initShapes() which populates this member variable:
-
- private void initShapes(){
-
- float triangleCoords[] = {
- // X, Y, Z
- -0.5f, -0.25f, 0,
- 0.5f, -0.25f, 0,
- 0.0f, 0.559016994f, 0
- };
-
- // initialize vertex Buffer for triangle
- ByteBuffer vbb = ByteBuffer.allocateDirect(
- // (# of coordinate values * 4 bytes per float)
- triangleCoords.length * 4);
- vbb.order(ByteOrder.nativeOrder());
- triangleVB = vbb.asFloatBuffer();
- triangleVB.put(triangleCoords);
- triangleVB.position(0);
-
- }
-
- This method defines a two-dimensional triangle shape with three equal sides.
-onSurfaceCreated() method to initialize your triangle:
-
- public void onSurfaceCreated(GL10 unused, EGLConfig config) {
-
- // Set the background frame color
- GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
-
- // initialize the triangle vertex array
- initShapes();
- }
-
- Warning: Shapes and other static objects should be initialized
- once in your onSurfaceCreated() method for best performance. Avoid initializing the
- new objects in onDrawFrame(), as this causes the system to re-create the objects
- for every frame redraw and slows down your application.
-
Now that you have defined a shape to draw, you can now use the OpenGL APIs to draw the - object. In order to do this with OpenGL ES 2.0, you must define a vertex shader and a -fragment shader to describe how to draw your shape.
- -To draw the triangle with OpenGL:
- -HelloOpenGLES20Renderer class, define a vertex shader and a fragment
-shader.
-
- private final String vertexShaderCode =
- "attribute vec4 vPosition; \n" +
- "void main(){ \n" +
- " gl_Position = vPosition; \n" +
- "} \n";
-
- private final String fragmentShaderCode =
- "precision mediump float; \n" +
- "void main(){ \n" +
- " gl_FragColor = vec4 (0.63671875, 0.76953125, 0.22265625, 1.0); \n" +
- "} \n";
-
- HelloOpenGLES20Renderer class, create a method for loading the shaders.
-
- private int loadShader(int type, String shaderCode){
-
- int shader = GLES20.glCreateShader(type);
-
- GLES20.glShaderSource(shader, shaderCode);
- GLES20.glCompileShader(shader);
-
- return shader;
- }
-
- HelloOpenGLES20Renderer class for an OpenGL
-Program.
-- private int mProgram; - private int maPositionHandle; --
onSurfaceCreated() method to load the shaders and attach them to a
-OpenGL Program.
-
- public void onSurfaceCreated(GL10 unused, EGLConfig config) {
-
- // Set the background frame color
- GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
-
- // initialize the triangle vertex array
- initShapes();
-
- // Create shaders for shape and attach to program
- int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
- int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);
-
- mProgram = GLES20.glCreateProgram();
- GLES20.glAttachShader(mProgram, vertexShader);
- GLES20.glAttachShader(mProgram, fragmentShader);
- GLES20.glLinkProgram(mProgram);
-
- maPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
- }
-
- At this point, you are ready to draw the triangle object in the OpenGL frame.
-onDrawFrame() method to draw the triangle.
-
- public void onDrawFrame(GL10 unused) {
-
- // Redraw background color
- GLES20.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
-
- // Specify a program with shaders
- GLES20.glUseProgram(mProgram);
-
- // Prepare the triangle data
- GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, 12, triangleVB);
- GLES20.glEnableVertexAttribArray(maPositionHandle);
-
- // Draw the triangle
- GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 3);
- }
-
- Note: Since the triangle is stationary at this point, the system is redrawing the - object repeatedly in exactly the same place and so is not the most efficient use of the OpenGL - graphics pipeline. In a later section, we add motion to the object to - justify this use of processing power.
-Try running this example application on your emulator or test device and -you should see something like this:
- -
-
-There are a few problems with this example. First of all, it's not going to impress your -friends. Secondly, the triangle is a bit squashed and changes shape when you change the screen -orientation of the test device. The reason the shape is skewed is due to the fact that the object is -being rendered in a frame which is not perfectly square. We fix that problem in the -next section.
- -OpenGL Projection and Views provide a way to calculate the coordinates of graphic objects in -realistic proportions on graphics displays of any size. One of the basic problems in displaying -graphics is that Android device displays are typically not square and—by default—OpenGL -happily maps a perfectly square, uniform coordinate system onto your typically non-square -screen.
- -
-
-The illustration above shows the uniform coordinate system assumed for an OpenGL frame on the - left, and how these coordinates actually map to a typical device screen in landscape orientation - on the right. To solve this problem, you can apply OpenGL projection modes and views to transform - object coordinates so your graphic objects have the correct proportions on any display.
- -To use a projection transformation on your triangle:
-HelloOpenGLES20Renderer class.
-- private int muMVPMatrixHandle; - private float[] mMVPMatrix = new float[16]; - private float[] mMMatrix = new float[16]; - private float[] mVMatrix = new float[16]; - private float[] mProjMatrix = new float[16]; --
vertexShaderCode string to add a variable for a model view
-projection matrix.
-
- private final String vertexShaderCode =
- "uniform mat4 uMVPMatrix; \n" +
- "attribute vec4 vPosition; \n" +
- "void main(){ \n" +
- " gl_Position = uMVPMatrix * vPosition; \n" +
- "} \n";
-
- onSurfaceChanged() method to reference the uMVPMatrix
-shader variable you added and define a view transformation matrix.
-
- public void onSurfaceCreated(GL10 unused, EGLConfig config) {
- ...
- maPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
-
- muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
- Matrix.setLookAtM(mVMatrix, 0, 0, 0, -3, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
- }
-
- onSurfaceChanged() method to calculate the device screen
-ration and create a projection matrix.
-
- public void onSurfaceChanged(GL10 unused, int width, int height) {
- GLES20.glViewport(0, 0, width, height);
-
- float ratio = (float) width / height;
- Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7);
- }
-
- onDrawFrame() method to apply the transformation.
-
- public void onDrawFrame(GL10 unused) {
- ...
- // Apply a ModelView Projection transformation
- Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
- GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix, 0);
-
- // Draw the triangle
- GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 3);
- }
-
- Try running this updated application on your emulator or test device and you should see -something like this:
- -
-
-Now that you have applied this transformation, the triangle has three equal sides, instead of the -squashed display in the earlier version.
- - -While it may be interesting exercise to create static graphic objects with OpenGL ES, chances -are you want at least some of your objects to move. In this section, we add motion to to our -triangle by rotating it.
- -To add rotation to your triangle:
-HelloOpenGLES20Renderer
-class.
- - private float[] mMMatrix = new float[16]; --
onDrawFrame() method to rotate the triangle object:
-
- public void onDrawFrame(GL10 gl) {
- ...
-
- // Create a rotation for the triangle
- long time = SystemClock.uptimeMillis() % 4000L;
- float angle = 0.090f * ((int) time);
- Matrix.setRotateM(mMMatrix, 0, angle, 0, 0, 1.0f);
- Matrix.multiplyMM(mMVPMatrix, 0, mVMatrix, 0, mMMatrix, 0);
- Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mMVPMatrix, 0);
-
- // Apply a ModelView Projection transformation
- //Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
- GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix, 0);
-
- // Draw the triangle
- ...
- }
-
- Run the application with this code and your triangle should rotate around its center.
- - - -Be sure to check out the OpenGL ES code samples are available in the -API -Demos sample application and listed in Related Samples -sidebar above. -