GL10 for Android

GLOneActivity.kt

import android.graphics.Bitmap
import android.graphics.Canvas
import android.opengl.GLES10
import android.opengl.GLSurfaceView
import android.os.Bundle
import android.support.design.widget.Snackbar
import android.support.v7.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_glone.*
import kotlinx.android.synthetic.main.content_glone.*
import java.nio.ByteBuffer
import java.nio.ByteOrder
import javax.microedition.khronos.egl.EGLConfig
import javax.microedition.khronos.opengles.GL10

class GLOneActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_glone)
        setSupportActionBar(toolbar)

        fab.setOnClickListener { view ->
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                .setAction("Action", null).show()
        }

        val triangleCoords = ByteBuffer.allocateDirect(9 * 4).order(ByteOrder.nativeOrder())
            .asFloatBuffer().put(floatArrayOf(
                +0.0f, +0.5f, 0.0f,
                -0.5f, -0.5f, 0.0f,
                +0.5f, -0.5f, 0.0f
            )).rewind()
        val rectangleCoords = ByteBuffer.allocateDirect(12 * 4).order(ByteOrder.nativeOrder())
            .asFloatBuffer().put(floatArrayOf(
                -0.7f, +0.7f, 0.0f,
                +0.7f, +0.7f, 0.0f,
                -0.7f, -0.7f, 0.0f,
                +0.7f, -0.7f, 0.0f
            )).rewind()

        val vertexCoords = ByteBuffer.allocateDirect(12 * 4).order(ByteOrder.nativeOrder())
            .asFloatBuffer().put(floatArrayOf(
                -1.0f, +1.0f, 0.0f,
                +1.0f, +1.0f, 0.0f,
                -1.0f, -1.0f, 0.0f,
                +1.0f, -1.0f, 0.0f
            )).rewind()

        val texCoords = ByteBuffer.allocateDirect(8 * 4).order(ByteOrder.nativeOrder())
            .asFloatBuffer().put(floatArrayOf(
                0.0f, 0.0f,
                1.0f, 0.0f,
                0.0f, 1.0f,
                1.0f, 1.0f
            )).rewind()

        val drawable = resources.getDrawable(R.mipmap.ic_launcher)
        val bitmap = Bitmap.createBitmap(drawable.intrinsicWidth, drawable.intrinsicHeight, Bitmap.Config.ARGB_8888)
        Canvas(bitmap).also {
            drawable.setBounds(0, 0, it.width, it.height)
            drawable.draw(it)
        }
        glSurfaceView.setRenderer(object : GLSurfaceView.Renderer {
            override fun onDrawFrame(gl: GL10?) {
                GLES10.glEnable(GLES10.GL_STENCIL_TEST)
                GLES10.glEnable(GLES10.GL_DEPTH_TEST)

                GLES10.glClearColor(0f, 0f, 0f, 1.0f)
                GLES10.glClearStencil(0)
                GLES10.glClear(GLES10.GL_COLOR_BUFFER_BIT.or(GLES10.GL_STENCIL_BUFFER_BIT).or(GLES10.GL_DEPTH_BUFFER_BIT))

//                GLES10.glColorMask(false, false, false, false)
//                GLES10.glDepthMask(false)
                GLES10.glStencilFunc(GLES10.GL_ALWAYS, 1, 0xFF)
                GLES10.glStencilOp(GLES10.GL_KEEP, GLES10.GL_KEEP, GLES10.GL_REPLACE)

                GLES10.glEnableClientState(GLES10.GL_VERTEX_ARRAY)
                GLES10.glColor4f(0.0f, 0.0f, 0.0f, 1.0f)
                GLES10.glVertexPointer(3, GLES10.GL_FLOAT, 0, triangleCoords)
                GLES10.glDrawArrays(GLES10.GL_TRIANGLES, 0, 3)

//                GLES10.glColorMask(true, true, true, true)
//                GLES10.glDepthMask(true)
                GLES10.glStencilFunc(GLES10.GL_NOTEQUAL, 1, 0xFF)
                GLES10.glStencilOp(GLES10.GL_KEEP, GLES10.GL_KEEP, GLES10.GL_KEEP)

                GLES10.glColor4f(0.0f, 1.0f, 1.0f, 1.0f)
                GLES10.glVertexPointer(3, GLES10.GL_FLOAT, 0, rectangleCoords)
                GLES10.glDrawArrays(GLES10.GL_TRIANGLE_STRIP, 0, 4)
            }

            override fun onSurfaceChanged(gl: GL10?, width: Int, height: Int) {
            }

            override fun onSurfaceCreated(gl: GL10?, config: EGLConfig?) {
            }
        })

//        glSurfaceView.setRenderer(object : GLSurfaceView.Renderer {
//            override fun onDrawFrame(gl: GL10?) {
//                GLES10.glClearColor(0f, 1.0f, 1.0f, 1.0f)
//                GLES10.glClear(GLES10.GL_COLOR_BUFFER_BIT)
//
//                GLES10.glEnable(GLES10.GL_TEXTURE_2D)
//                GLES10.glClientActiveTexture(GLES10.GL_TEXTURE0)
//                GLES10.glActiveTexture(GLES10.GL_TEXTURE0)
//                val textures = intArrayOf(0)
//                GLES10.glGenTextures(1, textures, 0)
//                GLES10.glBindTexture(GLES10.GL_TEXTURE_2D, textures[0])
//                GLES10.glTexParameterx(GLES10.GL_TEXTURE_2D, GLES10.GL_TEXTURE_MAG_FILTER, GLES10.GL_LINEAR)
//                GLES10.glTexParameterx(GLES10.GL_TEXTURE_2D, GLES10.GL_TEXTURE_MIN_FILTER, GLES10.GL_LINEAR)
//                GLES10.glTexParameterx(GLES10.GL_TEXTURE_2D, GLES10.GL_TEXTURE_WRAP_S, GLES10.GL_CLAMP_TO_EDGE)
//                GLES10.glTexParameterx(GLES10.GL_TEXTURE_2D, GLES10.GL_TEXTURE_WRAP_S, GLES10.GL_CLAMP_TO_EDGE)
//
//                val byteBuffer = ByteBuffer.allocateDirect(bitmap.width * bitmap.height * 4)
//                bitmap.copyPixelsToBuffer(byteBuffer)
//                byteBuffer.rewind()
//                GLES10.glTexImage2D(GLES10.GL_TEXTURE_2D, 0, GLES10.GL_RGBA, bitmap.width, bitmap.height, 0,
//                    GLES10.GL_RGBA, GLES10.GL_UNSIGNED_BYTE, byteBuffer)
//
//                GLES10.glEnableClientState(GLES10.GL_VERTEX_ARRAY)
//                GLES10.glEnableClientState(GLES10.GL_TEXTURE_COORD_ARRAY)
//
//                GLES10.glTexCoordPointer(2, GLES10.GL_FLOAT, 0, texCoords)
//                GLES10.glVertexPointer(3, GLES10.GL_FLOAT, 0, vertexCoords)
//                GLES10.glDrawArrays(GLES10.GL_TRIANGLE_STRIP, 0, 4)
//
//                GLES10.glDeleteTextures(1, textures, 0)
//                GLES10.glDisableClientState(GLES10.GL_VERTEX_ARRAY)
//                GLES10.glDisableClientState(GLES10.GL_TEXTURE_COORD_ARRAY)
//                GLES10.glDisable(GLES10.GL_TEXTURE_2D)
//            }
//
//            override fun onSurfaceChanged(gl: GL10?, width: Int, height: Int) {
//                GLES10.glViewport(0, 0, width, height)
//            }
//
//            override fun onSurfaceCreated(gl: GL10?, config: EGLConfig?) {
//            }
//        })
        glSurfaceView.renderMode = GLSurfaceView.RENDERMODE_WHEN_DIRTY
    }

}