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diff --git a/nuttx/graphics/nxglib/nxglib_splitline.c b/nuttx/graphics/nxglib/nxglib_splitline.c
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--- a/nuttx/graphics/nxglib/nxglib_splitline.c
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-/****************************************************************************
- * graphics/nxglib/nxglib_splitline.c
- *
- * Copyright (C) 2011-2012 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 <string.h>
-#include <errno.h>
-#include <stdlib.h>
-#include <debug.h>
-
-#include <nuttx/nx/nxglib.h>
-
-/****************************************************************************
- * Pre-Processor Definitions
- ****************************************************************************/
-
-/****************************************************************************
- * Private Types
- ****************************************************************************/
-
-struct b16point_s
-{
- b16_t x;
- b16_t y;
-};
-
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
-/****************************************************************************
- * Public Data
- ****************************************************************************/
-
-/****************************************************************************
- * Private Functions
- ****************************************************************************/
-
-static b16_t nxgl_interpolate(b16_t x, b16_t dy, b16_t dxdy)
-{
- b16_t dx = b16mulb16(dy, dxdy);
- return x + dx;
-}
-
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-
-/****************************************************************************
- * Name: nxgl_splitline
- *
- * Description:
- * In the general case, a line with width can be represented as a
- * parallelogram with a triangle at the top and bottom. Triangles and
- * parallelograms are both degenerate versions of a trapeziod. This
- * function breaks a wide line into triangles and trapezoids. This
- * function also detects other degenerate cases:
- *
- * 1. If y1 == y2 then the line is horizontal and is better represented
- * as a rectangle.
- * 2. If x1 == x2 then the line is vertical and also better represented
- * as a rectangle.
- * 3. If the width of the line is 1, then there are no triangles at the
- * top and bottome (this may also be the case if the width is narrow
- * and the line is near vertical).
- * 4. If the line is oriented is certain angles, it may consist only of
- * the upper and lower triangles with no trapezoid in between. In
- * this case, 3 trapezoids will be returned, but traps[1] will be
- * degenerate.
- *
- * Input parameters:
- * vector - A pointer to the vector described the line to be drawn.
- * traps - A pointer to a array of trapezoids (size 3).
- * rect - A pointer to a rectangle.
- *
- * Returned value:
- * 0: Line successfully broken up into three trapezoids. Values in
- * traps[0], traps[1], and traps[2] are valid.
- * 1: Line successfully represented by one trapezoid. Value in traps[1]
- * is valid.
- * 2: Line successfully represented by one rectangle. Value in rect is
- * valid
- * <0: On errors, a negated errno value is returned.
- *
- ****************************************************************************/
-
-int nxgl_splitline(FAR struct nxgl_vector_s *vector,
- FAR struct nxgl_trapezoid_s *traps,
- FAR struct nxgl_rect_s *rect,
- nxgl_coord_t linewidth)
-{
- struct nxgl_vector_s line;
- nxgl_coord_t iheight;
- nxgl_coord_t iwidth;
- nxgl_coord_t iyoffset;
- struct b16point_s quad[4];
- b16_t b16xoffset;
- b16_t b16yoffset;
- b16_t b16dxdy;
- b16_t angle;
- b16_t cosangle;
- b16_t sinangle;
- b16_t b16x;
- b16_t b16y;
-
- gvdbg("vector: (%d,%d)->(%d,%d) linewidth: %d\n",
- vector->pt1.x, vector->pt1.y, vector->pt2.x, vector->pt2.y, linewidth);
-
- /* First, check the linewidth */
-
- if (linewidth < 1)
- {
- return -EINVAL;
- }
-
- /* Then make sure that the start position of the line is above the end
- * position of the line... in raster order.
- */
-
- if (vector->pt1.y < vector->pt2.y)
- {
- /* Vector is already in raster order */
-
- memcpy(&line, vector, sizeof(struct nxgl_vector_s));
- }
- else if (vector->pt1.y > vector->pt2.y)
- {
- /* Swap the top and bottom */
-
- line.pt1.x = vector->pt2.x;
- line.pt1.y = vector->pt2.y;
- line.pt2.x = vector->pt1.x;
- line.pt2.y = vector->pt1.y;
- }
- else /* if (vector->pt1.y == vector->pt2.y) */
- {
- /* First degenerate case: The line is horizontal. */
-
- if (vector->pt1.x < vector->pt2.x)
- {
- rect->pt1.x = vector->pt1.x;
- rect->pt2.x = vector->pt2.x;
- }
- else
- {
- rect->pt1.x = vector->pt2.x;
- rect->pt2.x = vector->pt1.x;
- }
-
- /* The height of the rectangle is the width of the line, half above
- * and half below.
- */
-
- rect->pt1.y = vector->pt1.y - (linewidth >> 1);
- rect->pt2.y = rect->pt1.y + linewidth - 1;
-
- gvdbg("Horizontal rect: (%d,%d),(%d,%d)\n",
- rect->pt1.x, rect->pt1.y, rect->pt2.x, rect->pt2.y);
-
- return 2;
- }
-
- /* Check if the line is vertical */
-
- if (line.pt1.x == line.pt2.x)
- {
- /* Second degenerate case: The line is vertical. */
-
- rect->pt1.y = line.pt1.y;
- rect->pt2.y = line.pt2.y;
-
- rect->pt1.x = line.pt1.x - (linewidth >> 1);
- rect->pt2.x = rect->pt1.x + linewidth - 1;
-
- gvdbg("Vertical rect: (%d,%d),(%d,%d)\n",
- rect->pt1.x, rect->pt1.y, rect->pt2.x, rect->pt2.y);
-
- return 2;
- }
-
- /* The final degenerate case */
-
- if (linewidth == 1 &&
- abs(line.pt2.x - line.pt1.x) < (line.pt2.y - line.pt1.y))
- {
- /* A close to vertical line of width 1 is basically
- * a single parallelogram of width 1.
- */
-
- traps[1].top.x1 = itob16(line.pt1.x);
- traps[1].top.x2 = traps[1].top.x1;
- traps[1].top.y = line.pt1.y;
-
- traps[1].bot.x1 = itob16(line.pt2.x);
- traps[1].bot.x2 = traps[1].bot.x1;
- traps[1].bot.y = line.pt2.y;
-
- gvdbg("Vertical traps[1]: (%08x,%08x,%d),(%08x,%08x, %d)\n",
- traps[1].top.x1, traps[1].top.x2, traps[1].top.y,
- traps[1].bot.x1, traps[1].bot.x2, traps[1].bot.y);
-
- return 1;
- }
-
- /* Okay, then what remains is interesting.
- *
- * iheight = |y2 - y1|
- * iwidth = |x2 - x1|
- */
-
- iheight = line.pt2.y - line.pt1.y + 1;
- if (line.pt1.x < line.pt2.x)
- {
- iwidth = line.pt2.x - line.pt1.x + 1;
- }
- else
- {
- iwidth = line.pt1.x - line.pt2.x + 1;
- }
-
- /* Applying the line width to the line results in a rotated, rectangle.
- * Get the Y offset from an end of the original thin line to a corner of the fat line.
- *
- * Angle of line: angle = atan2(iheight, iwidth)
- * Y offset from line: b16yoffset = linewidth * cos(angle)
- *
- * For near verical lines, b16yoffset is be nearly zero. For near horizontal
- * lines, b16yOffset is be about the same as linewidth.
- */
-
- angle = b16atan2(itob16(iheight), itob16(iwidth));
- cosangle = b16cos(angle);
- b16yoffset = (linewidth * cosangle + 1) >> 1;
-
- /* Get the X offset from an end of the original thin line to a corner of the fat line.
- *
- * For near vertical lines, b16xoffset is about the same as linewidth. For near
- * horizontal lines, b16xoffset is nearly zero.
- */
-
- sinangle = b16sin(angle);
- b16xoffset = (linewidth * sinangle + 1) >> 1;
-
- gvdbg("height: %d width: %d angle: %08x b16yoffset: %08x b16xoffset: %08x\n",
- iheight, iwidth, angle, b16yoffset, b16xoffset);
-
- /* Now we know all four points of the rotated rectangle */
-
- iyoffset = b16toi(b16yoffset + b16HALF);
- if (iyoffset > 0)
- {
- /* Get the Y positions of each point */
-
- b16y = itob16(line.pt1.y);
- quad[0].y = b16y - b16yoffset;
- quad[1].y = b16y + b16yoffset;
-
- b16y = itob16(line.pt2.y);
- quad[2].y = b16y - b16yoffset;
- quad[3].y = b16y + b16yoffset;
-
- if (line.pt1.x < line.pt2.x)
- {
- /* Line is going "south east". Get the X positions of each point */
-
- b16x = itob16(line.pt1.x);
- quad[0].x = b16x + b16xoffset;
- quad[1].x = b16x - b16xoffset;
-
- b16x = itob16(line.pt2.x);
- quad[2].x = b16x + b16xoffset;
- quad[3].x = b16x - b16xoffset;
-
- gvdbg("Southeast: quad (%08x,%08x),(%08x,%08x),(%08x,%08x),(%08x,%08x)\n",
- quad[0].x, quad[0].y, quad[1].x, quad[1].y,
- quad[2].x, quad[2].y, quad[3].x, quad[3].y);
-
- /* Now we can form the trapezoids. The top of the first trapezoid
- * (triangle) is at quad[0]
- */
-
- traps[0].top.x1 = quad[0].x;
- traps[0].top.x2 = quad[0].x;
- traps[0].top.y = b16toi(quad[0].y + b16HALF);
-
- /* The bottom of the first trapezoid (triangle) may be either at
- * quad[1] or quad[2], depending upon orientation.
- */
-
- if (quad[1]. y < quad[2].y)
- {
- /* quad[1] is at the bottom left of the triangle. Interpolate
- * to get the corresponding point on the right side.
- *
- * Interpolation is from quad[0] along the line quad[0]->quad[2]
- * which as the same slope as the line (positive)
- */
-
- b16dxdy = itob16(iwidth) / iheight;
-
- traps[0].bot.x1 = quad[1].x;
- traps[0].bot.x2 = nxgl_interpolate(quad[0].x, quad[1].y - quad[0].y, b16dxdy);
- traps[0].bot.y = b16toi(quad[1].y + b16HALF);
-
- /* quad[1] is at the top left of the second trapezoid. quad[2} is
- * at the bottom right of the second trapezoid. Interpolate to get
- * corresponding point on the left side.
- *
- * Interpolation is from quad[1] along the line quad[1]->quad[3]
- * which as the same slope as the line (positive)
- */
-
- traps[1].top.x1 = traps[0].bot.x1;
- traps[1].top.x2 = traps[0].bot.x2;
- traps[1].top.y = traps[0].bot.y;
-
- traps[1].bot.x1 = nxgl_interpolate(traps[1].top.x1, quad[2].y - quad[1].y, b16dxdy);
- traps[1].bot.x2 = quad[2].x;
- traps[1].bot.y = b16toi(quad[2].y + b16HALF);
- }
- else
- {
- /* quad[2] is at the bottom right of the triangle. Interpolate
- * to get the corresponding point on the left side.
- *
- * Interpolation is from quad[0] along the line quad[0]->quad[1]
- * which orthogonal to the slope of the line (and negative)
- */
-
- b16dxdy = -itob16(iheight) / iwidth;
-
- traps[0].bot.x1 = nxgl_interpolate(quad[0].x, quad[2].y - quad[0].y, b16dxdy);
- traps[0].bot.x2 = quad[2].x;
- traps[0].bot.y = b16toi(quad[2].y + b16HALF);
-
- /* quad[2] is at the top right of the second trapezoid. quad[1} is
- * at the bottom left of the second trapezoid. Interpolate to get
- * corresponding point on the right side.
- *
- * Interpolation is from quad[2] along the line quad[2]->quad[3]
- * which as the same slope as the previous interpolation.
- */
-
- traps[1].top.x1 = traps[0].bot.x1;
- traps[1].top.x2 = traps[0].bot.x2;
- traps[1].top.y = traps[0].bot.y;
-
- traps[1].bot.x1 = quad[1].x;
- traps[1].bot.x2 = nxgl_interpolate(traps[1].top.x2, quad[1].y - quad[2].y, b16dxdy);
- traps[1].bot.y = b16toi(quad[1].y + b16HALF);
- }
-
- /* The final trapezond (triangle) at the bottom is new well defined */
-
- traps[2].top.x1 = traps[1].bot.x1;
- traps[2].top.x2 = traps[1].bot.x2;
- traps[2].top.y = traps[1].bot.y;
-
- traps[2].bot.x1 = quad[3].x;
- traps[2].bot.x2 = quad[3].x;
- traps[2].bot.y = b16toi(quad[3].y + b16HALF);
- }
- else
- {
- /* Get the X positions of each point */
-
- b16x = itob16(line.pt1.x);
- quad[0].x = b16x - b16xoffset;
- quad[1].x = b16x + b16xoffset;
-
- b16x = itob16(line.pt2.x);
- quad[2].x = b16x - b16xoffset;
- quad[3].x = b16x + b16xoffset;
-
- gvdbg("Southwest: quad (%08x,%08x),(%08x,%08x),(%08x,%08x),(%08x,%08x)\n",
- quad[0].x, quad[0].y, quad[1].x, quad[1].y,
- quad[2].x, quad[2].y, quad[3].x, quad[3].y);
-
- /* Now we can form the trapezoids. The top of the first trapezoid
- * (triangle) is at quad[0]
- */
-
- traps[0].top.x1 = quad[0].x;
- traps[0].top.x2 = quad[0].x;
- traps[0].top.y = b16toi(quad[0].y + b16HALF);
-
- /* The bottom of the first trapezoid (triangle) may be either at
- * quad[1] or quad[2], depending upon orientation.
- */
-
- if (quad[1].y < quad[2].y)
- {
- /* quad[1] is at the bottom right of the triangle. Interpolate
- * to get the corresponding point on the left side.
- *
- * Interpolation is from quad[0] along the line quad[0]->quad[2]
- * which as the same slope as the line (negative)
- */
-
- b16dxdy = -itob16(iwidth) / iheight;
-
- traps[0].bot.x1 = nxgl_interpolate(traps[0].top.x1, quad[1].y - quad[0].y, b16dxdy);
- traps[0].bot.x2 = quad[1].x;
- traps[0].bot.y = b16toi(quad[1].y + b16HALF);
-
- /* quad[1] is at the top right of the second trapezoid. quad[2} is
- * at the bottom left of the second trapezoid. Interpolate to get
- * corresponding point on the right side.
- *
- * Interpolation is from quad[1] along the line quad[1]->quad[3]
- * which as the same slope as the line (negative)
- */
-
- traps[1].top.x1 = traps[0].bot.x1;
- traps[1].top.x2 = traps[0].bot.x2;
- traps[1].top.y = traps[0].bot.y;
-
- traps[1].bot.x1 = quad[2].x;
- traps[1].bot.x2 = nxgl_interpolate(traps[1].top.x2, quad[2].y - quad[1].y, b16dxdy);
- traps[1].bot.y = b16toi(quad[2].y + b16HALF);
- }
- else
- {
- /* quad[2] is at the bottom left of the triangle. Interpolate
- * to get the corresponding point on the right side.
- *
- * Interpolation is from quad[0] along the line quad[0]->quad[1]
- * which orthogonal to the slope of the line (and positive)
- */
-
- b16dxdy = itob16(iheight) / iwidth;
-
- traps[0].bot.x1 = quad[2].x;
- traps[0].bot.x2 = nxgl_interpolate(traps[0].top.x2, quad[2].y - quad[0].y, b16dxdy);
- traps[0].bot.y = b16toi(quad[2].y + b16HALF);
-
- /* quad[2] is at the top left of the second trapezoid. quad[1} is
- * at the bottom right of the second trapezoid. Interpolate to get
- * corresponding point on the left side.
- *
- * Interpolation is from quad[2] along the line quad[2]->quad[3]
- * which as the same slope as the previous interpolation.
- */
-
- traps[1].top.x1 = traps[0].bot.x1;
- traps[1].top.x2 = traps[0].bot.x2;
- traps[1].top.y = traps[0].bot.y;
-
- traps[1].bot.x1 = nxgl_interpolate(traps[1].top.x1, quad[1].y - quad[2].y, b16dxdy);
- traps[1].bot.x2 = quad[1].x;
- traps[1].bot.y = b16toi(quad[1].y + b16HALF);
- }
-
- /* The final trapezond (triangle) at the bottom is new well defined */
-
- traps[2].top.x1 = traps[1].bot.x1;
- traps[2].top.x2 = traps[1].bot.x2;
- traps[2].top.y = traps[1].bot.y;
-
- traps[2].bot.x1 = quad[3].x;
- traps[2].bot.x2 = quad[3].x;
- traps[2].bot.y = b16toi(quad[3].y + b16HALF);
- }
-
- gvdbg("traps[0]: (%08x,%08x,%d),(%08x,%08x,%d)\n",
- traps[0].top.x1, traps[0].top.x2, traps[0].top.y,
- traps[0].bot.x1, traps[0].bot.x2, traps[0].bot.y);
- gvdbg("traps[1]: (%08x,%08x,%d),(%08x,%08x,%d)\n",
- traps[1].top.x1, traps[1].top.x2, traps[1].top.y,
- traps[1].bot.x1, traps[1].bot.x2, traps[1].bot.y);
- gvdbg("traps[2]: (%08x,%08x,%d),(%08x,%08x,%d)\n",
- traps[2].top.x1, traps[2].top.x2, traps[2].top.y,
- traps[2].bot.x1, traps[2].bot.x2, traps[2].bot.y);
-
- return 0;
- }
-
- /* The line is too vertical to have any significant triangular top or
- * bottom. Just return the center parallelogram.
- */
-
- traps[1].top.x1 = itob16(line.pt1.x - (linewidth >> 1));
- traps[1].top.x2 = traps[1].top.x1 + itob16(linewidth - 1);
- traps[1].top.y = line.pt1.y;
-
- traps[1].bot.x1 = itob16(line.pt2.x - (linewidth >> 1));
- traps[1].bot.x2 = traps[1].bot.x1 + itob16(linewidth - 1);
- traps[1].bot.y = line.pt2.y;
-
- gvdbg("Horizontal traps[1]: (%08x,%08x,%d),(%08x,%08x, %d)\n",
- traps[1].top.x1, traps[1].top.x2, traps[1].top.y,
- traps[1].bot.x1, traps[1].bot.x2, traps[1].bot.y);
-
- return 1;
-}
-
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