Working OpenGLES demo.

2017-07-03 20:26:38 +02:00 · 2017-07-03 20:26:38 +02:00 · 58d7c7f6b3
commit 58d7c7f6b3
31 changed files with 705 additions and 0 deletions
--- a/app/src/main/java/com/codigoparallevar/minicards/rendering/Triangle.java
+++ b/app/src/main/java/com/codigoparallevar/minicards/rendering/Triangle.java
@ -0,0 +1,80 @@
+package com.codigoparallevar.minicards.rendering;
+
+import android.opengl.GLES20;
+import android.util.Log;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.FloatBuffer;
+
+public class Triangle {
+
+    private final String vertexShaderCode =
+            "attribute vec4 vPosition;" +
+            "void main(){" +
+                "gl_Position = vPosition;" +
+            "}";
+
+    private final String fragmentShaderCode =
+            "precision mediump float;" +
+            "uniform vec4 vColor;" +
+            "void main(){" +
+                "gl_FragColor = vColor;" +
+            "}";
+
+    private FloatBuffer vertexBuffer;
+    private final int mProgram;
+
+    static final int COORDS_PER_VERTEX = 3;
+    static float triangleCoords[] = {
+             0.0f,  0.622008459f, 0.0f, // top
+            -0.5f, -0.311004243f, 0.0f, // bottom left
+             0.5f, -0.311004243f, 0.0f  // bottom right
+    };
+
+    // Set color with red, green, blue and alpha (opacity) values
+    float color[] = { 0.63671875f, 0.76953125f, 0.22265625f, 1.0f };
+    private int mPositionHandle;
+    private int mColorHandle;
+
+    private final int vertexCount = triangleCoords.length / COORDS_PER_VERTEX;
+    private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex
+
+    public Triangle(){
+        ByteBuffer bb = ByteBuffer.allocateDirect(triangleCoords.length * 4);
+        bb.order(ByteOrder.nativeOrder());
+
+        vertexBuffer = bb.asFloatBuffer();
+        vertexBuffer.put(triangleCoords);
+        vertexBuffer.position(0);
+
+        int vertexShader = MyGlRenderer.loadShader(GLES20.GL_VERTEX_SHADER,
+                                                   vertexShaderCode);
+        int fragmentShader = MyGlRenderer.loadShader(GLES20.GL_FRAGMENT_SHADER,
+                                                     fragmentShaderCode);
+
+        mProgram = GLES20.glCreateProgram();
+        GLES20.glAttachShader(mProgram, vertexShader);
+        GLES20.glAttachShader(mProgram, fragmentShader);
+
+        GLES20.glLinkProgram(mProgram);
+    }
+
+    public void draw(){
+        GLES20.glUseProgram(mProgram);
+
+        mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
+        GLES20.glEnableVertexAttribArray(mPositionHandle);
+
+        GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX,
+                                     GLES20.GL_FLOAT, false,
+                                     vertexStride, vertexBuffer);
+
+        mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
+
+        GLES20.glUniform4fv(mColorHandle, 1, color, 0);
+        Log.d("Triangle", "VB "+ vertexBuffer.get(1));
+        GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vertexCount);
+        GLES20.glDisableVertexAttribArray(mPositionHandle);
+    }
+}