/** * Allocates and initializes OpenGL resources needed by the background renderer. Must be * called on the OpenGL thread, typically in * {@link GLSurfaceView.Renderer#onSurfaceCreated(GL10, EGLConfig)}. * * @param context Needed to access shader source. */ public void CreateOnGlThread(Context context) { // Generate the background texture. var textures = new int[1]; //GLES20 = OpenGL ES 2.0 //Gibt eine bestimmte Anzahl an freien Texturnamen zurück. GLES20.GlGenTextures(1, textures, 0); TextureId = textures[0]; GLES20.GlBindTexture(mTextureTarget, TextureId); GLES20.GlTexParameteri(mTextureTarget, GLES20.GlTextureWrapS, GLES20.GlClampToEdge); GLES20.GlTexParameteri(mTextureTarget, GLES20.GlTextureWrapT, GLES20.GlClampToEdge); GLES20.GlTexParameteri(mTextureTarget, GLES20.GlTextureMinFilter, GLES20.GlNearest); GLES20.GlTexParameteri(mTextureTarget, GLES20.GlTextureMagFilter, GLES20.GlNearest); int numVertices = 4; if (numVertices != QUAD_COORDS.Length / COORDS_PER_VERTEX) { throw new Exception("Unexpected number of vertices in BackgroundRenderer."); } var bbVertices = ByteBuffer.AllocateDirect(QUAD_COORDS.Length * FLOAT_SIZE); bbVertices.Order(ByteOrder.NativeOrder()); mQuadVertices = bbVertices.AsFloatBuffer(); mQuadVertices.Put(QUAD_COORDS); mQuadVertices.Position(0); var bbTexCoords = ByteBuffer.AllocateDirect(numVertices * TEXCOORDS_PER_VERTEX * FLOAT_SIZE); bbTexCoords.Order(ByteOrder.NativeOrder()); mQuadTexCoord = bbTexCoords.AsFloatBuffer(); mQuadTexCoord.Put(QUAD_TEXCOORDS); mQuadTexCoord.Position(0); var bbTexCoordsTransformed = ByteBuffer.AllocateDirect(numVertices * TEXCOORDS_PER_VERTEX * FLOAT_SIZE); bbTexCoordsTransformed.Order(ByteOrder.NativeOrder()); mQuadTexCoordTransformed = bbTexCoordsTransformed.AsFloatBuffer(); int vertexShader = ShaderUtil.LoadGLShader(TAG, context, GLES20.GlVertexShader, Resource.Raw.screenquad_vertex); int fragmentShader = ShaderUtil.LoadGLShader(TAG, context, GLES20.GlFragmentShader, Resource.Raw.screenquad_fragment_oes); mQuadProgram = GLES20.GlCreateProgram(); GLES20.GlAttachShader(mQuadProgram, vertexShader); GLES20.GlAttachShader(mQuadProgram, fragmentShader); GLES20.GlLinkProgram(mQuadProgram); GLES20.GlUseProgram(mQuadProgram); ShaderUtil.CheckGLError(TAG, "Program creation"); mQuadPositionParam = GLES20.GlGetAttribLocation(mQuadProgram, "a_Position"); mQuadTexCoordParam = GLES20.GlGetAttribLocation(mQuadProgram, "a_TexCoord"); ShaderUtil.CheckGLError(TAG, "Program parameters"); }