+++ /dev/null
-/* $XConsortium: miscanfill.h,v 1.5 94/04/17 20:27:50 dpw Exp $ */
-/*
-
-Copyright (c) 1987 X Consortium
-
-Permission is hereby granted, free of charge, to any person obtaining
-a copy of this software and associated documentation files (the
-"Software"), to deal in the Software without restriction, including
-without limitation the rights to use, copy, modify, merge, publish,
-distribute, sublicense, and/or sell copies of the Software, and to
-permit persons to whom the Software is furnished to do so, subject to
-the following conditions:
-
-The above copyright notice and this permission notice shall be included
-in all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
-OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
-IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR
-OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
-ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
-OTHER DEALINGS IN THE SOFTWARE.
-
-Except as contained in this notice, the name of the X Consortium shall
-not be used in advertising or otherwise to promote the sale, use or
-other dealings in this Software without prior written authorization
-from the X Consortium.
-
-*/
-
-
-#ifndef SCANFILLINCLUDED
-#define SCANFILLINCLUDED
-/*
- * scanfill.h
- *
- * Written by Brian Kelleher; Jan 1985
- *
- * This file contains a few macros to help track
- * the edge of a filled object. The object is assumed
- * to be filled in scanline order, and thus the
- * algorithm used is an extension of Bresenham's line
- * drawing algorithm which assumes that y is always the
- * major axis.
- * Since these pieces of code are the same for any filled shape,
- * it is more convenient to gather the library in one
- * place, but since these pieces of code are also in
- * the inner loops of output primitives, procedure call
- * overhead is out of the question.
- * See the author for a derivation if needed.
- */
-\f
-
-/*
- * In scan converting polygons, we want to choose those pixels
- * which are inside the polygon. Thus, we add .5 to the starting
- * x coordinate for both left and right edges. Now we choose the
- * first pixel which is inside the pgon for the left edge and the
- * first pixel which is outside the pgon for the right edge.
- * Draw the left pixel, but not the right.
- *
- * How to add .5 to the starting x coordinate:
- * If the edge is moving to the right, then subtract dy from the
- * error term from the general form of the algorithm.
- * If the edge is moving to the left, then add dy to the error term.
- *
- * The reason for the difference between edges moving to the left
- * and edges moving to the right is simple: If an edge is moving
- * to the right, then we want the algorithm to flip immediately.
- * If it is moving to the left, then we don't want it to flip until
- * we traverse an entire pixel.
- */
-#define BRESINITPGON(dy, x1, x2, xStart, d, m, m1, incr1, incr2) { \
- int dx; /* local storage */ \
-\
- /* \
- * if the edge is horizontal, then it is ignored \
- * and assumed not to be processed. Otherwise, do this stuff. \
- */ \
- if ((dy) != 0) { \
- xStart = (x1); \
- dx = (x2) - xStart; \
- if (dx < 0) { \
- m = dx / (dy); \
- m1 = m - 1; \
- incr1 = -2 * dx + 2 * (dy) * m1; \
- incr2 = -2 * dx + 2 * (dy) * m; \
- d = 2 * m * (dy) - 2 * dx - 2 * (dy); \
- } else { \
- m = dx / (dy); \
- m1 = m + 1; \
- incr1 = 2 * dx - 2 * (dy) * m1; \
- incr2 = 2 * dx - 2 * (dy) * m; \
- d = -2 * m * (dy) + 2 * dx; \
- } \
- } \
-}
-\f
-#define BRESINCRPGON(d, minval, m, m1, incr1, incr2) { \
- if (m1 > 0) { \
- if (d > 0) { \
- minval += m1; \
- d += incr1; \
- } \
- else { \
- minval += m; \
- d += incr2; \
- } \
- } else {\
- if (d >= 0) { \
- minval += m1; \
- d += incr1; \
- } \
- else { \
- minval += m; \
- d += incr2; \
- } \
- } \
-}
-
-\f
-/*
- * This structure contains all of the information needed
- * to run the bresenham algorithm.
- * The variables may be hardcoded into the declarations
- * instead of using this structure to make use of
- * register declarations.
- */
-typedef struct {
- int minor; /* minor axis */
- int d; /* decision variable */
- int m, m1; /* slope and slope+1 */
- int incr1, incr2; /* error increments */
-} BRESINFO;
-
-
-#define BRESINITPGONSTRUCT(dmaj, min1, min2, bres) \
- BRESINITPGON(dmaj, min1, min2, bres.minor, bres.d, \
- bres.m, bres.m1, bres.incr1, bres.incr2)
-
-#define BRESINCRPGONSTRUCT(bres) \
- BRESINCRPGON(bres.d, bres.minor, bres.m, bres.m1, bres.incr1, bres.incr2)
-
-
-#endif
projects / rdpsrv / blobdiff