/****************************************************************************
* graphics/nxglib/lcd/nxglib_filltrapezoid.c
*
* Copyright (C) 2010-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <fixedmath.h>
#include <nuttx/lcd/lcd.h>
#include <nuttx/nx/nxglib.h>
#include "nxglib_bitblit.h"
#include "nxglib_fillrun.h"
/****************************************************************************
* Pre-Processor Definitions
****************************************************************************/
#ifndef NXGLIB_SUFFIX
# error "NXGLIB_SUFFIX must be defined before including this header file"
#endif
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxglib_filltrapezoid_*bpp
*
* Descripton:
* Fill a trapezoidal region in the LCD memory with a fixed color.
* Clip the trapezoid to lie within a boundng box. This is useful for
* drawing complex shapes that can be broken into a set of trapezoids.
*
****************************************************************************/
void NXGL_FUNCNAME(nxgl_filltrapezoid,NXGLIB_SUFFIX)
(FAR struct lcd_planeinfo_s *pinfo,
FAR const struct nxgl_trapezoid_s *trap,
FAR const struct nxgl_rect_s *bounds,
NXGL_PIXEL_T color)
{
unsigned int ncols;
unsigned int topy;
unsigned int boty;
unsigned int row;
unsigned int botw;
b16_t topx1;
b16_t topx2;
b16_t botx1;
b16_t botx2;
b16_t dx1dy;
b16_t dx2dy;
int dy;
int ix1;
int ix2;
/* Get the top run endpoints */
topx1 = trap->top.x1;
topx2 = trap->top.x2;
/* Calculate the number of rows to render */
topy = trap->top.y;
boty = trap->bot.y;
/* Get the bottom run endpoints */
botx1 = trap->bot.x1;
botx2 = trap->bot.x2;
/* Calculate the slope of the left and right side of the trapezoid */
dy = boty - topy;
if (dy > 0)
{
dx1dy = b16divi((botx1 - topx1), dy);
dx2dy = b16divi((botx2 - topx2), dy);
}
else
{
/* The trapezoid is a run! Use the average width. */
topx1 = (topx1 + botx1) >> 1;
topx2 = (topx2 + botx2) >> 1;
botx1 = topx1;
botx2 = topx2;
dx1dy = 0;
dx2dy = 0;
}
/* Perform vertical clipping */
if (topy < bounds->pt1.y)
{
/* Is the entire trapezoid "above" the clipping window? */
if (boty < bounds->pt1.y)
{
/* Yes.. then do nothing */
return;
}
/* Calculate the x values for the new top run */
dy = bounds->pt1.y - topy;
topx1 += dy * dx1dy;
topx2 += dy * dx2dy;
/* Clip the top row to render */
topy = bounds->pt1.y;
}
if (boty > bounds->pt2.y)
{
/* Is the entire trapezoid "below" the clipping window? */
if (topy > bounds->pt2.y)
{
/* Yes.. then do nothing */
return;
}
/* Calculate the x values for the new bottom run */
dy = boty - bounds->pt2.y;
botx1 -= dy * dx1dy;
botx2 -= dy * dx2dy;
/* Clip the bottom row to render */
boty = bounds->pt2.y;
}
/* Handle the special case where the sides cross (as in an hourglass) */
if (botx1 > botx2)
{
b16_t tmp;
ngl_swap(botx1, botx2, tmp);
}
/* Fill the run buffer for the maximum run that we will need */
ix1 = b16toi(topx1);
ix1 = ngl_clipl(ix1, bounds->pt1.x);
ix2 = b16toi(topx2);
ix2 = ngl_clipr(ix2, bounds->pt2.x);
ncols = ix2 - ix1 + 1;
ix1 = b16toi(botx1);
ix1 = ngl_clipl(ix1, bounds->pt1.x);
ix2 = b16toi(botx2);
ix2 = ngl_clipr(ix2, bounds->pt2.x);
botw = ix2 - ix1 + 1;
if (ncols < botw)
{
ncols = botw;
}
NXGL_FUNCNAME(nxgl_fillrun,NXGLIB_SUFFIX)((NXGLIB_RUNTYPE*)pinfo->buffer, color, ncols);
/* Then fill the trapezoid row-by-row */
for (row = topy; row <= boty; row++)
{
/* Handle the special case where the sides cross (as in an hourglass) */
if (topx1 > topx2)
{
b16_t tmp;
ngl_swap(topx1, topx2, tmp);
ngl_swap(dx1dy, dx2dy, tmp);
}
/* Convert the positions to integer and get the run width, clipping to
* fit within the bounding box.
*/
ix1 = b16toi(topx1);
ix1 = ngl_clipl(ix1, bounds->pt1.x);
ix2 = b16toi(topx2);
ix2 = ngl_clipr(ix2, bounds->pt2.x);
/* Handle some corner cases where we draw nothing. Otherwise, we will
* always draw at least one pixel.
*/
if (ix1 <= ix2)
{
/* Then draw the run from ix1 to ix2 at row */
ncols = ix2 - ix1 + 1;
(void)pinfo->putrun(row, ix1, pinfo->buffer, ncols);
}
/* Add the dx/dy value to get the run positions on the next row */
topx1 += dx1dy;
topx2 += dx2dy;
}
}
