function _imce_watermark::create_watermark in IMCE Watermark 6.2

Same name and namespace in other branches

1. 7 imce_watermark.module \_imce_watermark::create_watermark()

File

./imce_watermark.module, line 254

Adding watermar for IMCE uploaded images.

Class

_imce_watermark

Code

function create_watermark($main_img_obj, $watermark_img_obj, $alpha_level = 100) {
  $alpha_level /= 100;

  # convert 0-100 (%) alpha to decimal

  # calculate our images dimensions
  $main_img_obj_w = imagesx($main_img_obj);
  $main_img_obj_h = imagesy($main_img_obj);
  $watermark_img_obj_w = imagesx($watermark_img_obj);
  $watermark_img_obj_h = imagesy($watermark_img_obj);
  $vm = variable_get('imce_watermark_vertical_margin', 0);
  $hm = variable_get('imce_watermark_horizontal_margin', 0);
  switch (variable_get('imce_watermark_horizontal_position', 0)) {
    case 0:
      $main_img_obj_min_x = $hm;
      $main_img_obj_max_x = $watermark_img_obj_w + $hm;
      break;
    case 1:

      # determine center position coordinates
      $main_img_obj_min_x = floor($main_img_obj_w / 2 - $watermark_img_obj_w / 2) + $hm;
      $main_img_obj_max_x = ceil($main_img_obj_w / 2 + $watermark_img_obj_w / 2) + $hm;
      break;
    case 2:
      $main_img_obj_min_x = $main_img_obj_w - $watermark_img_obj_w + $hm;
      $main_img_obj_max_x = $main_img_obj_w + $hm;
      break;
  }
  switch (variable_get('imce_watermark_vertical_position', 0)) {
    case 0:
      $main_img_obj_min_y = $vm;
      $main_img_obj_max_y = $watermark_img_obj_h + $hm;
      break;
    case 1:
      $main_img_obj_min_y = floor($main_img_obj_h / 2 - $watermark_img_obj_h / 2) + $hm;
      $main_img_obj_max_y = ceil($main_img_obj_h / 2 + $watermark_img_obj_h / 2) + $hm;
      break;
    case 2:
      $main_img_obj_min_y = $main_img_obj_h - $watermark_img_obj_h + $vm;
      $main_img_obj_max_y = $main_img_obj_h + $hm;
      break;
  }

  # create new image to hold merged changes
  $return_img = imagecreatetruecolor($main_img_obj_w, $main_img_obj_h);

  # walk through main image
  for ($y = 0; $y < $main_img_obj_h; $y++) {
    for ($x = 0; $x < $main_img_obj_w; $x++) {
      $return_color = NULL;

      # determine the correct pixel location within our watermark
      $watermark_x = $x - $main_img_obj_min_x;
      $watermark_y = $y - $main_img_obj_min_y;

      # fetch color information for both of our images
      $main_rgb = imagecolorsforindex($main_img_obj, imagecolorat($main_img_obj, $x, $y));

      # if our watermark has a non-transparent value at this pixel intersection

      # and we're still within the bounds of the watermark image
      if ($watermark_x >= 0 && $watermark_x < $watermark_img_obj_w && $watermark_y >= 0 && $watermark_y < $watermark_img_obj_h) {
        $watermark_rbg = imagecolorsforindex($watermark_img_obj, imagecolorat($watermark_img_obj, $watermark_x, $watermark_y));

        # using image alpha, and user specified alpha, calculate average
        $watermark_alpha = round((127 - $watermark_rbg['alpha']) / 127, 2);
        $watermark_alpha = $watermark_alpha * $alpha_level;

        # calculate the color 'average' between the two - taking into account the specified alpha level
        $avg_red = $this
          ->_get_ave_color($main_rgb['red'], $watermark_rbg['red'], $watermark_alpha);
        $avg_green = $this
          ->_get_ave_color($main_rgb['green'], $watermark_rbg['green'], $watermark_alpha);
        $avg_blue = $this
          ->_get_ave_color($main_rgb['blue'], $watermark_rbg['blue'], $watermark_alpha);

        # calculate a color index value using the average RGB values we've determined
        $return_color = $this
          ->_get_image_color($return_img, $avg_red, $avg_green, $avg_blue);

        # if we're not dealing with an average color here, then let's just copy over the main color
      }
      else {
        $return_color = imagecolorat($main_img_obj, $x, $y);
      }

      # END if watermark

      # draw the appropriate color onto the return image
      imagesetpixel($return_img, $x, $y, $return_color);
    }

    # END for each X pixel
  }

  # END for each Y pixel

  # return the resulting, watermarked image for display
  return $return_img;
}