+++ /dev/null
-/**
- * \file
- * <!--
- * Copyright 2005 Develer S.r.l. (http://www.develer.com/)
- * This file is part of DevLib - See README.devlib for information.
- * -->
- *
- * \version $Id$
- * \author Massimiliano Corsini <chad@develer.com>
- *
- *
- * \brief Low-level drawing routines.
- *
- * This file contains the implementation of the low-level drawing routines
- * to draw fill rectangle, fill triangle and so on.
- *
- */
-
-/*#*
- *#* $Log$
- *#* Revision 1.1 2006/07/19 13:00:01 bernie
- *#* Import into DevLib.
- *#*
- *#* Revision 1.10 2005/10/15 15:03:43 rasky
- *#* Remove per-pixel clipping from line().
- *#* Use clipLine() also for a-scope.
- *#*
- *#* Revision 1.9 2005/10/14 15:21:32 eldes
- *#* Implement the cohen-sutherland clipping on the buffer
- *#*
- *#* Revision 1.8 2005/09/27 13:28:10 rasky
- *#* Add clipping capabilities to line()
- *#* Fix off-by-one computation of rectangles of drawing.
- *#*
- *#* Revision 1.7 2005/09/27 10:41:35 rasky
- *#* Import line-drawing routine from Devlib
- *#*
- *#* Revision 1.6 2005/09/19 16:36:05 chad
- *#* Fix doxygen autobrief
- *#*
- *#* Revision 1.5 2005/07/06 12:51:47 chad
- *#* Make the fillRectangle() independent of the order of the points of the rectangle
- *#*
- *#* Revision 1.4 2005/06/17 15:06:36 chad
- *#* Remove conversion warning
- *#*
- *#* Revision 1.3 2005/06/17 15:04:47 chad
- *#* Add line clipping capability
- *#*
- *#* Revision 1.2 2005/06/15 14:04:43 chad
- *#* Add line routine
- *#*
- *#* Revision 1.1 2005/06/15 13:34:34 chad
- *#* Low-level drawing routines
- *#*
- *#*/
-
-// Qt-specific headers
-#include <qpoint.h>
-
-
-/**
- * Low-level routine to draw a line.
- *
- * This routine is based on the Bresenham Line-Drawing Algorithm.
- *
- * The \a stride represents the width of the image buffer.
- * (\a x1, \a y1) are the coordinates of the starting point.
- * (\a x2, \a y2) are the coordinates of the ending point.
- *
- * The line has no anti-alias, and clipping is not performed. The line
- * must be fully contained in the buffer (use clipLine() if you need
- * to clip it).
- */
-void line(unsigned char *buf,
- unsigned long bufw, unsigned long bufh, unsigned long stride,
- int x1, int y1, int x2, int y2, unsigned char color)
-{
- int x, y, e, len, adx, ady, signx, signy;
-
- if (x2 > x1)
- {
- /* left to right */
- signx = +1;
- adx = x2 - x1;
- }
- else
- {
- /* right to left */
- signx = -1;
- adx = x1 - x2;
- }
-
- if (y2 > y1)
- {
- /* top to bottom */
- signy = +1;
- ady = y2 - y1;
- }
- else
- {
- /* bottom to top */
- signy = -1;
- ady = y1 - y2;
- }
-
- x = x1;
- y = y1;
-
- if (adx > ady)
- {
- /* X-major line (octants 1/4/5/8) */
- len = adx;
- e = -adx;
- while (len--)
- {
- /* Sanity check */
- assert(y >= 0 && y < static_cast<int>(bufh) &&
- x >= 0 && x < static_cast<int>(bufw));
- buf[y * stride + x] = color;
- x += signx;
- e += ady;
- if (e >= 0)
- {
- y += signy;
- e -= adx;
- }
- }
- }
- else
- {
- /* Y-major line (octants 2/3/6/7) */
- len = ady;
- e = -ady;
- while (len--)
- {
- /* Sanity check */
- assert(y >= 0 && y < static_cast<int>(bufh) &&
- x >= 0 && x < static_cast<int>(bufw));
- buf[y * stride + x] = color;
- y += signy;
- e += adx;
- if (e >= 0)
- {
- x += signx;
- e -= ady;
- }
- }
- }
-}
-
-/// Helper routine for clipLine().
-static int region(int x, int y, int w, int h)
-{
- int code = 0;
-
- if (y >= h)
- code |= 1; // top
- else if (y < 0)
- code |= 2; // bottom
-
- if (x >= w)
- code |= 4; // right
- else if (x < 0)
- code |= 8; // left
-
- return code;
-}
-
-/**
- * Low-level routine to draw a line, clipped to the buffer extents.
- *
- * This routine executes the clipping, and then invokes line().
- * Parameters are the same of line(). The clipping is performed
- * using the Cohen-Sutherland algorithm, which is very fast.
- */
-void clipLine(unsigned char *buf,
- unsigned long w, unsigned long h, unsigned long stride,
- int x1, int y1, int x2, int y2, unsigned char color)
-{
- int code1 = region(x1, y1, w, h);
- int code2 = region(x2, y2, w, h);
-
- // Loop while there is at least one point outside
- while (code1 | code2)
- {
- // Check for line totally outside
- if (code1 & code2)
- return;
-
- int c = code1 ? code1 : code2;
- int x, y;
-
- if (c & 1) // top
- {
- x = x1 + (x2 - x1) * (h - y1) / (y2 - y1);
- y = h - 1;
- }
- else if (c & 2) //bottom
- {
- x = x1 + (x2 - x1) * -y1 / (y2 - y1);
- y = 0;
- }
- else if (c & 4) //right
- {
- y = y1 + (y2 - y1) * (w - x1) / (x2 - x1);
- x = w - 1;
- }
- else //left
- {
- y = y1 + (y2 - y1) * -x1 / (x2 - x1);
- x = 0;
- }
-
- if (c == code1) // first endpoint was clipped
- {
- x1 = x; y1 = y;
- code1 = region(x1, y1, w, h);
- }
- else //second endpoint was clipped
- {
- x2 = x; y2 = y;
- code2 = region(x2, y2, w, h);
- }
- }
-
- line(buf, w, h, stride, x1, y1, x2, y2, color);
-}
-
-
-/**
- * Low-level routine to draw a filled rectangle.
- *
- * The triangle is filled with the given color.
- *
- * The \a stride represents the width of the image buffer.
- * The points \a p1 and \a p2 are two opposite corners of the
- * rectangle.
- */
-void fillRectangle(unsigned char *buf, unsigned long stride,
- QPoint p1, QPoint p2, unsigned char color)
-{
- QPoint ul; // upper-left corner
- QPoint lr; // lower-right corner
-
- if (p2.x() > p1.x())
- {
- ul.setX(p1.x());
- lr.setX(p2.x());
- }
- else
- {
- ul.setX(p2.x());
- lr.setX(p1.x());
- }
-
- if (p2.y() > p1.y())
- {
- ul.setY(p1.y());
- lr.setY(p2.y());
- }
- else
- {
- ul.setY(p2.y());
- lr.setY(p1.y());
- }
-
- int width = lr.x() - ul.x();
- unsigned long offset = ul.x() + ul.y()*stride;
-
- for (int h = ul.y(); h < lr.y(); h++)
- {
- memset(buf+offset, color, width);
- offset += stride;
- }
-}
-
-/**
- * Low-level routines to draw a filled triangle.
- *
- * The triangle is filled with the given \a color.
- * The \a stride represents the width of the image buffer (\a buf).
- *
- * The routine use fixed-point arithmetic.
- */
-void fillTriangle(unsigned char* buf, unsigned long stride,
- QPoint v1, QPoint v2, QPoint v3, unsigned char color)
-{
- int altezza[3];
-
- // Sort by vertical coordinate
- if (v1.y() > v2.y())
- std::swap(v1, v2);
- if (v1.y() > v3.y())
- std::swap(v1, v3);
- if (v2.y() > v3.y())
- std::swap(v2, v3);
-
- altezza[0] = v3.y() - v1.y();
- if (!altezza[0])
- return;
-
- int sezioni = 2;
- int sezione = 1;
-
- buf += v1.y() * stride;
-
- altezza[1] = v2.y() - v1.y();
- altezza[2] = v3.y() - v2.y();
-
- int sinistra = v1.x();
- int destra = sinistra;
-
- if (v1.y() == v2.y())
- {
- if (v1.x() < v2.x())
- destra = v2.x();
- else
- sinistra = v2.x();
- }
-
- sinistra <<= 16;
- destra <<= 16;
-
- int stmp1, stmp2, stmp3;
-
- stmp1 = (altezza[1] << 16) / altezza[0];
- int lunghezza = stmp1 * (v3.x() - v1.x()) + ((v1.x() - v2.x()) << 16);
-
- if (!lunghezza )
- return;
-
- int delta_sinistra[2];
- int delta_destra[2];
-
- stmp1 = ((v3.x() - v1.x()) << 16) / altezza[0];
-
- if (altezza[1])
- stmp2 = ((v2.x() - v1.x()) << 16) / altezza[1];
- if (altezza[2])
- stmp3 = ((v3.x() - v2.x()) << 16) / altezza[2];
-
- if (lunghezza < 0) // Il secondo vertice ~J a destra
- {
- delta_sinistra[0] = stmp1;
- delta_sinistra[1] = stmp1;
- delta_destra[0] = stmp2;
- delta_destra[1] = stmp3;
- }
- else // Il secondo vertice ~J a sinistra
- {
- delta_sinistra[0] = stmp2;
- delta_sinistra[1] = stmp3;
- delta_destra[0] = stmp1;
- delta_destra[1] = stmp1;
- }
-
- int len2 = lunghezza;
-
- do
- {
- while (altezza [sezione])
- {
- unsigned char* curpos = buf + ((sinistra )>> 16);
- lunghezza = ((destra ) >> 16) - ((sinistra ) >> 16);
- assert(lunghezza >= 0);
- if (lunghezza)
- memset(curpos, color, lunghezza);
- buf += stride;
- destra += delta_destra[sezione - 1];
- sinistra += delta_sinistra[sezione - 1];
- altezza[sezione]--;
- }
- if (len2 < 0)
- destra = v2.x() << 16;
- else
- sinistra = v2.x() << 16;
- sezione++;
- } while (--sezioni);
-}