drivers/displays/tft/controls/progressbar.c

   1 /**************************************************************************/
   2 /*!
   3     @file     progressbar.c
   4     @author   K. Townsend (microBuilder.eu)
   5
   6     @brief    Renders a progress bar
   7
   8     @section LICENSE
   9
  10     Software License Agreement (BSD License)
  11
  12     Copyright (c) 2012, K. Townsend
  13     All rights reserved.
  14
  15     Redistribution and use in source and binary forms, with or without
  16     modification, are permitted provided that the following conditions are met:
  17     1. Redistributions of source code must retain the above copyright
  18     notice, this list of conditions and the following disclaimer.
  19     2. Redistributions in binary form must reproduce the above copyright
  20     notice, this list of conditions and the following disclaimer in the
  21     documentation and/or other materials provided with the distribution.
  22     3. Neither the name of the copyright holders nor the
  23     names of its contributors may be used to endorse or promote products
  24     derived from this software without specific prior written permission.
  25
  26     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
  27     EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  28     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  29     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
  30     DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  31     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  32     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  33     ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36 */
  37 /**************************************************************************/
  38 #include <string.h>
  39
  40 #include "progressbar.h"
  41
  42 /**************************************************************************/
  43 /*!
  44     @brief  Draws a simple (empty) rectangle
  45
  46     @param[in]  x
  47                 Starting x co-ordinate
  48     @param[in]  y
  49                 Starting y co-ordinate
  50     @param[in]  width
  51                 Button width in pixels
  52     @param[in]  height
  53                 Button height in pixels
  54     @param[in]  progress
  55                 Progress in percent from 0..100
  56     @param[in]  color
  57                 Color used when rendering the progress bar
  58
  59     @note   Because all displays with built-in controllers and SRAM are
  60             inherently single-buffered -- meaning you can see the updates
  61             as you draw them -- you need to be very careful to try to avoid
  62             tearing or 'blinking' effects.  This is usually caused by
  63             writing the same pixel twice with different colors (for example
  64             filling a background and then drawing something on top of it).
  65
  66             This progress bar avoids this blinking effect by only drawing
  67             the background gradient where it is visible, and no beneath the
  68             progress bar itself.
  69 */
  70 /**************************************************************************/
  71 void progressbarRender(uint16_t x, uint16_t y, uint16_t width, uint16_t height, uint8_t progress, uint16_t color, theme_t theme)
  72 {
  73   uint16_t brighter, darker;
  74   uint16_t progressEnd;
  75
  76   // Figure out the size of the progress bar
  77   progressEnd = x + (((width-2) * progress)/100);
  78
  79   // Make sure we don't end up in negative territory with really small values
  80   if (progressEnd < x + 2) progressEnd = x+2;
  81
  82   // Draw the outline and background gradient
  83   // This needs to be square to avoid flickering with rapid updates :/
  84   drawRectangle(x, y, x+width, y+height, theme.colorBorderDarker);
  85   drawRectangle(x+1, y+1, x+width-1, y+height-1, theme.colorFill);
  86   drawGradient(progressEnd+1, y+2, x+width-2, y+height-2, theme.colorFill, theme.colorBorder);
  87
  88   // Draw the progress gradient if required
  89   if (progress)
  90   {
  91     // Calculate slightly brighter and darker colors for the border and gradient
  92     brighter = colorsAlphaBlend(COLOR_WHITE, color, 50);
  93     darker = colorsAlphaBlend(COLOR_BLACK, color, 35);
  94     // Draw border rectangle and gradient fill
  95     drawRectangle(x+2, y+2, progressEnd, y+height-2, darker);
  96     drawGradient(x+3, y+3, progressEnd-1, y+height-3, brighter, color);
  97   }
  98 }