docs: 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;
      }