x11/region.d

   1 module iv.x11.region /*is aliced*/;
   2
   3 import core.stdc.config;
   4
   5 import iv.alice;
   6 import iv.x11.xlib : XPoint;
   7
   8 extern (C) @trusted nothrow @nogc:
   9
  10
  11 struct XBoxRec {
  12   short x1, x2, y1, y2;
  13 }
  14 alias XBox = XBoxRec*;
  15 //alias BOX = Box;
  16 //alias BoxRec = Box;
  17
  18
  19 /*
  20 struct XRectangleRec {
  21   short x, y, width, height;
  22 }
  23 alias XRegionRect = XRectangleRec*;
  24 */
  25 //alias RECTANGLE = Rectangle;
  26 //alias RectangleRec = Rectangle;
  27 //alias RectanglePtr = Rectangle*;
  28
  29
  30 /*
  31  *   clip region
  32  */
  33 struct XRegionRec {
  34   c_long size;
  35   c_long numRects;
  36   XBox rects;
  37   XBoxRec extents;
  38 }
  39 alias XRegion = XRegionRec*;
  40 //alias REGION = XRegionRec;
  41
  42
  43 //enum int TRUE      = 1;
  44 //enum int FALSE     = 0;
  45 private enum int MAXSHORT  = 32767;
  46 private enum int MINSHORT  = -MAXSHORT;
  47
  48
  49 private T MAX(T) (T a, T b) { return (a < b ? b : a); }
  50 private T MIN(T) (T a, T b) { return (a > b ? b : a); }
  51
  52
  53 /*  1 if two BOXs overlap.
  54  *  0 if two BOXs do not overlap.
  55  *  Remember, x2 and y2 are not in the region
  56  */
  57 bool EXTENTCHECK (in XBox r1, in XBox r2) {
  58   return
  59     (r1.x2 > r2.x1) &&
  60     (r1.x1 < r2.x2) &&
  61     (r1.y2 > r2.y1) &&
  62     (r1.y1 < r2.y2);
  63 }
  64
  65 /*
  66  *  update region extents
  67  */
  68 void EXTENTS (XBox r, XRegion idRect) {
  69   if (r.x1 < idRect.extents.x1) idRect.extents.x1 = r.x1;
  70   if (r.y1 < idRect.extents.y1) idRect.extents.y1 = r.y1;
  71   if (r.x2 > idRect.extents.x2) idRect.extents.x2 = r.x2;
  72   if (r.y2 > idRect.extents.y2) idRect.extents.y2 = r.y2;
  73 }
  74
  75 /*
  76  *   Check to see if there is enough memory in the present region.
  77  */
  78 bool MEMCHECK (XRegion reg, XBox rect, XBox firstrect) {
  79   static void *Xrealloc (void *ptr, usize size) @trusted nothrow @nogc {
  80     import core.stdc.stdlib : realloc;
  81     return realloc(ptr, (size == 0 ? 1 : size));
  82   }
  83
  84   bool result = false;
  85   if (reg.numRects >= reg.size-1) {
  86     firstrect = cast(XBox)Xrealloc(cast(void*)firstrect, cast(uint)(2*XBoxRec.sizeof*reg.size));
  87     if (firstrect is null) {
  88       result = false;
  89     } else {
  90       reg.size *= 2;
  91       rect = &firstrect[reg.numRects];
  92       result = true;
  93     }
  94   }
  95   return result;
  96 }
  97
  98 /*  this routine checks to see if the previous rectangle is the same
  99  *  or subsumes the new rectangle to add.
 100  */
 101 bool CHECK_PREVIOUS (in XRegion Reg, in XBox R, short Rx1, short Ry1, short Rx2, short Ry2) {
 102   return !(Reg.numRects > 0 && (R-1).y1 == Ry1 && (R-1).y2 == Ry2 && (R-1).x1 <= Rx1 && (R-1).x2 >= Rx2);
 103 }
 104
 105 /*  add a rectangle to the given Region */
 106 void ADDRECT (XRegion reg, XBox r, short rx1, short ry1, short rx2, short ry2) {
 107   if (rx1 < rx2 && ry1 < ry2 && CHECK_PREVIOUS(reg, r, rx1, ry1, rx2, ry2)) {
 108     r.x1 = rx1;
 109     r.y1 = ry1;
 110     r.x2 = rx2;
 111     r.y2 = ry2;
 112     EXTENTS(r, reg);
 113     ++reg.numRects;
 114     ++r;
 115   }
 116 }
 117
 118 /*  add a rectangle to the given Region */
 119 void ADDRECTNOX (XRegion reg, XBox r, short rx1, short ry1, short rx2, short ry2) {
 120   if (rx1 < rx2 && ry1 < ry2 && CHECK_PREVIOUS(reg, r, rx1, ry1, rx2, ry2)) {
 121     r.x1 = rx1;
 122     r.y1 = ry1;
 123     r.x2 = rx2;
 124     r.y2 = ry2;
 125     ++reg.numRects;
 126     ++r;
 127   }
 128 }
 129
 130 void EMPTY_REGION (XRegion pReg) {
 131   pReg.numRects = 0;
 132 }
 133
 134 c_long REGION_NOT_EMPTY (in XRegion pReg) {
 135   return pReg.numRects;
 136 }
 137
 138 bool INBOX (in XBox r, short x, short y) {
 139   return (r.x2 > x && r.x1 <= x && r.y2 > y && r.y1 <= y);
 140 }
 141
 142 /*
 143  * number of points to buffer before sending them off
 144  * to scanlines() :  Must be an even number
 145  */
 146 enum int NUMPTSTOBUFFER = 200;
 147
 148 /*
 149  * used to allocate buffers for points and link
 150  * the buffers together
 151  */
 152 struct POINTBLOCK {
 153   XPoint[NUMPTSTOBUFFER] pts;
 154   POINTBLOCK* next;
 155 }