// started from https://github.com/google/grafika/blob/f3c8c3dee60153f471312e21acac8b3a3cddd7dc/src/com/android/grafika/gles/GlUtil.java
/*
* Copyright 2014 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.cine.android.streaming.gles;
import android.opengl.GLES20;
import android.opengl.GLES30;
import android.opengl.Matrix;
import android.util.Log;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
/**
* Some OpenGL utility functions.
*/
public class GlUtil {
public static final String TAG = "GlUtil";
/**
* Identity matrix for general use. Don't modify or life will get weird.
*/
public static final float[] IDENTITY_MATRIX;
static {
IDENTITY_MATRIX = new float[16];
Matrix.setIdentityM(IDENTITY_MATRIX, 0);
}
private static final int SIZEOF_FLOAT = 4;
private GlUtil() {
} // do not instantiate
/**
* Creates a new program from the supplied vertex and fragment shaders.
*
* @return A handle to the program, or 0 on failure.
*/
public static int createProgram(String vertexSource, String fragmentSource) {
int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource);
if (vertexShader == 0) {
return 0;
}
int pixelShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource);
if (pixelShader == 0) {
return 0;
}
int program = GLES20.glCreateProgram();
checkGlError("glCreateProgram");
if (program == 0) {
Log.e(TAG, "Could not create program");
}
GLES20.glAttachShader(program, vertexShader);
checkGlError("glAttachShader");
GLES20.glAttachShader(program, pixelShader);
checkGlError("glAttachShader");
GLES20.glLinkProgram(program);
int[] linkStatus = new int[1];
GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linkStatus, 0);
if (linkStatus[0] != GLES20.GL_TRUE) {
Log.e(TAG, "Could not link program: ");
Log.e(TAG, GLES20.glGetProgramInfoLog(program));
GLES20.glDeleteProgram(program);
program = 0;
}
return program;
}
/**
* Compiles the provided shader source.
*
* @return A handle to the shader, or 0 on failure.
*/
public static int loadShader(int shaderType, String source) {
int shader = GLES20.glCreateShader(shaderType);
checkGlError("glCreateShader type=" + shaderType);
GLES20.glShaderSource(shader, source);
GLES20.glCompileShader(shader);
int[] compiled = new int[1];
GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0);
if (compiled[0] == 0) {
Log.e(TAG, "Could not compile shader " + shaderType + ":");
Log.e(TAG, " " + GLES20.glGetShaderInfoLog(shader));
GLES20.glDeleteShader(shader);
shader = 0;
}
return shader;
}
/**
* Checks to see if a GLES error has been raised.
*/
public static void checkGlError(String op) {
int error = GLES20.glGetError();
if (error != GLES20.GL_NO_ERROR) {
String msg = op + ": glError 0x" + Integer.toHexString(error);
Log.e(TAG, msg);
throw new RuntimeException(msg);
}
}
/**
* Checks to see if the location we obtained is valid. GLES returns -1 if a label
* could not be found, but does not set the GL error.
* <p/>
* Throws a RuntimeException if the location is invalid.
*/
public static void checkLocation(int location, String label) {
if (location < 0) {
throw new RuntimeException("Unable to locate '" + label + "' in program");
}
}
/**
* Creates a texture from raw data.
*
* @param data Image data, in a "direct" ByteBuffer.
* @param width Texture width, in pixels (not bytes).
* @param height Texture height, in pixels.
* @param format Image data format (use constant appropriate for glTexImage2D(), e.g. GL_RGBA).
* @return Handle to texture.
*/
public static int createImageTexture(ByteBuffer data, int width, int height, int format) {
int[] textureHandles = new int[1];
int textureHandle;
GLES20.glGenTextures(1, textureHandles, 0);
textureHandle = textureHandles[0];
GlUtil.checkGlError("glGenTextures");
// Bind the texture handle to the 2D texture target.
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle);
// Configure min/mag filtering, i.e. what scaling method do we use if what we're rendering
// is smaller or larger than the source image.
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER,
GLES20.GL_LINEAR);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER,
GLES20.GL_LINEAR);
GlUtil.checkGlError("loadImageTexture");
// Load the data from the buffer into the texture handle.
GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, /*level*/ 0, format,
width, height, /*border*/ 0, format, GLES20.GL_UNSIGNED_BYTE, data);
GlUtil.checkGlError("loadImageTexture");
return textureHandle;
}
/**
* Allocates a direct float buffer, and populates it with the float array data.
*/
public static FloatBuffer createFloatBuffer(float[] coords) {
// Allocate a direct ByteBuffer, using 4 bytes per float, and copy coords into it.
ByteBuffer bb = ByteBuffer.allocateDirect(coords.length * SIZEOF_FLOAT);
bb.order(ByteOrder.nativeOrder());
FloatBuffer fb = bb.asFloatBuffer();
fb.put(coords);
fb.position(0);
return fb;
}
/**
* Writes GL version info to the log.
*/
public static void logVersionInfo() {
Log.i(TAG, "vendor : " + GLES20.glGetString(GLES20.GL_VENDOR));
Log.i(TAG, "renderer: " + GLES20.glGetString(GLES20.GL_RENDERER));
Log.i(TAG, "version : " + GLES20.glGetString(GLES20.GL_VERSION));
if (false) {
int[] values = new int[1];
GLES30.glGetIntegerv(GLES30.GL_MAJOR_VERSION, values, 0);
int majorVersion = values[0];
GLES30.glGetIntegerv(GLES30.GL_MINOR_VERSION, values, 0);
int minorVersion = values[0];
if (GLES30.glGetError() == GLES30.GL_NO_ERROR) {
Log.i(TAG, "iversion: " + majorVersion + "." + minorVersion);
}
}
}
}
