Add initial OpenGL example

[~andy/spades] / src / org / pileus / spades / Cards.java

diff --git a/src/org/pileus/spades/Cards.java b/src/org/pileus/spades/Cards.java
index 59679742cdd1de70d8c55be5bbe53ba23144c5d2..083bf6fdbec86fbd33cc071ff66a49a6e5617fe1 100644 (file)
--- a/src/org/pileus/spades/Cards.java
+++ b/src/org/pileus/spades/Cards.java
@@ -1,10 +1,110 @@
 package org.pileus.spades;
 
-public class Cards
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.FloatBuffer;
+
+import javax.microedition.khronos.egl.EGLConfig;
+import javax.microedition.khronos.opengles.GL10;
+
+import android.opengl.GLES20;
+import android.opengl.GLSurfaceView;
+
+import android.content.Context;
+
+public class Cards extends GLSurfaceView implements GLSurfaceView.Renderer
 {
-       /* Public Methods */
-       public Cards()
+       /* Shader data */
+       private final String vertSource =
+               "attribute vec4 vPosition;"  +
+               "void main() {"              +
+               "  gl_Position = vPosition;" +
+               "}";
+
+       private final String fragSource =
+               "precision mediump float;" +
+               "uniform vec4 vColor;"     +
+               "void main() {"            +
+               "  gl_FragColor = vColor;" +
+               "}";
+
+       /* Drawing data */
+       private final float coords[] = {
+               0.0f,  0.5f, 0.0f,
+               -0.5f, -0.5f, 0.0f,
+               0.5f, -0.5f, 0.0f,
+       };
+
+       private final float color[] = { 1, 0, 0, 1 };
+
+       /* Private data */
+       private int         program;
+       private FloatBuffer vertBuf;
+
+       /* Private methods */
+       private int loadShader(int type, String code)
+       {
+               int shader = GLES20.glCreateShader(type);
+               GLES20.glShaderSource(shader, code);
+               GLES20.glCompileShader(shader);
+               return shader;
+       }
+
+       /* GLSurfaceView Methods */
+       public Cards(Context context)
        {
+               super(context);
                Os.debug("Cards create");
+
+               this.setEGLContextClientVersion(2);
+               this.setRenderer(this);
+               this.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
+       }
+
+       /* Renderer methods */
+       @Override
+       public void onSurfaceCreated(GL10 unused, EGLConfig config)
+       {
+               /* Initialize shaders */
+               int vertShader = this.loadShader(GLES20.GL_VERTEX_SHADER,   vertSource);
+               int fragShader = this.loadShader(GLES20.GL_FRAGMENT_SHADER, fragSource);
+
+               /* Link shaders into an OpenGL program */
+               this.program = GLES20.glCreateProgram();
+               GLES20.glAttachShader(program, vertShader);
+               GLES20.glAttachShader(program, fragShader);
+               GLES20.glLinkProgram(program);
+
+               /* Create Vertex Array  */
+               ByteBuffer byteBuf = ByteBuffer.allocateDirect(coords.length * 4);
+               byteBuf.order(ByteOrder.nativeOrder());
+
+               this.vertBuf = byteBuf.asFloatBuffer();
+               this.vertBuf.put(coords);
+               this.vertBuf.position(0);
+       }
+
+       @Override
+       public void onDrawFrame(GL10 unused)
+       {
+               /* Turn on the program */
+               GLES20.glUseProgram(program);
+               int posHandle = GLES20.glGetAttribLocation(program, "vPosition");
+               int clrHandle = GLES20.glGetUniformLocation(program, "vColor");
+
+               /* Draw */
+               GLES20.glClearColor(0, 0, 0, 1);
+               GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
+               GLES20.glEnableVertexAttribArray(posHandle);
+               GLES20.glVertexAttribPointer(posHandle, 3, GLES20.GL_FLOAT, false, 3*4, vertBuf);
+               GLES20.glUniform4fv(clrHandle, 1, color, 0);
+               GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 3);
+               GLES20.glDisableVertexAttribArray(posHandle);
+       }
+
+       @Override
+       public void onSurfaceChanged(GL10 unused, int width, int height)
+       {
+               GLES20.glViewport(0, 0, width, height);
        }
 }