From 7474aa4080077d0ce41f1e426d2e75f19bdc4878 Mon Sep 17 00:00:00 2001
From: Andy Spencer <andy753421@gmail.com>
Date: Sun, 14 Apr 2013 05:13:30 +0000
Subject: [PATCH] Add initial OpenGL example

---
 res/layout/main.xml              |  12 +++-
 src/org/pileus/spades/Cards.java | 106 ++++++++++++++++++++++++++++++-
 src/org/pileus/spades/Main.java  |  10 ++-
 3 files changed, 120 insertions(+), 8 deletions(-)

diff --git a/res/layout/main.xml b/res/layout/main.xml
index 6b683d1..cde15f7 100644
--- a/res/layout/main.xml
+++ b/res/layout/main.xml
@@ -50,11 +50,17 @@
 						android:text="Send" />
 				</LinearLayout>
 			</LinearLayout>
-			<TextView
+			<LinearLayout
 				android:id="@+id/spades"
+				android:orientation="vertical"
 				android:layout_width="fill_parent"
-				android:layout_height="fill_parent"
-				android:text="Spades" />
+				android:layout_height="fill_parent">
+				<TextView
+					android:id="@+id/spades_text"
+					android:layout_width="fill_parent"
+					android:layout_height="wrap_content"
+					android:text="Spades" />
+			</LinearLayout>
 			<ScrollView
 				android:id="@+id/debug_scroll"
 				android:layout_width="fill_parent"
diff --git a/src/org/pileus/spades/Cards.java b/src/org/pileus/spades/Cards.java
index 5967974..083bf6f 100644
--- 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);
 	}
 }
diff --git a/src/org/pileus/spades/Main.java b/src/org/pileus/spades/Main.java
index 3c39414..0eae72e 100644
--- a/src/org/pileus/spades/Main.java
+++ b/src/org/pileus/spades/Main.java
@@ -31,6 +31,7 @@ public class Main extends Activity
 	private boolean      ready;
 	private String       topic;
 	private String       names;
+	private Cards        cards;
 
 	/* Widgets */
 	private TabHost      window;
@@ -39,7 +40,7 @@ public class Main extends Activity
 	private TextView     log;
 	private EditText     input;
 	private Button       send;
-	private TextView     spades;
+	private LinearLayout spades;
 	private TextView     debug;
 
 	private ScrollView   lscroll;
@@ -210,7 +211,7 @@ public class Main extends Activity
 			this.log       = (TextView)     findViewById(R.id.log);
 			this.input     = (EditText)     findViewById(R.id.input);
 			this.send      = (Button)       findViewById(R.id.send);
-			this.spades    = (TextView)     findViewById(R.id.spades);
+			this.spades    = (LinearLayout) findViewById(R.id.spades);
 			this.debug     = (TextView)     findViewById(R.id.debug);
 
 			this.lscroll   = (ScrollView)   findViewById(R.id.log_scroll);
@@ -231,6 +232,11 @@ public class Main extends Activity
 					.newTabSpec("debug")
 					.setIndicator("Debug")
 					.setContent(R.id.debug));
+
+			// Setup OpenGL view
+			this.cards = new Cards(this);
+			this.spades.addView(cards);
+			
 		} catch (Exception e) {
 			Os.debug("Error setting content view", e);
 			return;
-- 
2.43.2