/* ** ** This library module contains the ppmdraw routines. ** ** Copyright (C) 1989, 1991 by Jef Poskanzer. ** ** Permission to use, copy, modify, and distribute this software and its ** documentation for any purpose and without fee is hereby granted, provided ** that the above copyright notice appear in all copies and that both that ** copyright notice and this permission notice appear in supporting ** documentation. This software is provided "as is" without express or ** implied warranty. ** ** The character drawing routines are by John Walker ** Copyright (C) 1994 by John Walker, kelvin@fourmilab.ch */ #include #include #include "pm_config.h" #include "pm_c_util.h" #include "mallocvar.h" #include "ppm.h" #include "ppmdfont.h" #include "ppmdraw.h" struct penpos { int x; int y; }; static long int const DDA_SCALE = 8192; #define PPMD_MAXCOORD 32767 /* Several factors govern the limit of x, y coordination values. The limit must be representable as (signed) int for coordinates to be carried in struct penpos (immediately above). The following calculation, done with long ints, must not overflow: cy0 = cy0 + (y1 - cy0) * (cols - 1 - cx0) / (x1 - cx0); The following must not overflow when DDA_SCALE is set to 8092: dy = (y1 - y0) * DDA_SCALE / abs(x1 - x0); Overflow conditions for ppmd_text are rather complicated, for commands come from an external PPMD font file. See comments below. */ static void ppmd_validateCoords(int const x, int const y) { if (x < -PPMD_MAXCOORD || x > PPMD_MAXCOORD) pm_error("x coordinate out of bounds: %d", x); if (y < -PPMD_MAXCOORD || y > PPMD_MAXCOORD) pm_error("y coordinate out of bounds: %d", y); } static void drawPoint(ppmd_drawproc drawproc, const void * const clientdata, pixel ** const pixels, int const cols, int const rows, pixval const maxval, int const x, int const y) { /*---------------------------------------------------------------------------- Draw a single point, assuming that it is within the bounds of the image. -----------------------------------------------------------------------------*/ if (drawproc == PPMD_NULLDRAWPROC) { const pixel * const pixelP = clientdata; assert(x >= 0); assert(x < cols); assert(y >= 0); assert(y < rows); pixels[y][x] = *pixelP; } else drawproc(pixels, cols, rows, maxval, x, y, clientdata); } void ppmd_point_drawproc(pixel** const pixels, int const cols, int const rows, pixval const maxval, int const x, int const y, const void* const clientdata) { if (x >= 0 && x < cols && y >= 0 && y < rows) pixels[y][x] = *((pixel*)clientdata); } /* Simple fill routine. */ void ppmd_filledrectangle(pixel ** const pixels, int const cols, int const rows, pixval const maxval, int const x, int const y, int const width, int const height, ppmd_drawproc drawProc, const void * const clientdata) { int cx, cy, cwidth, cheight, row; /* Clip. */ cx = x; cy = y; cwidth = width; cheight = height; if (cx < 0) { cx = 0; cwidth += x; } if (cy < 0) { cy = 0; cheight += y; } if (cx + cwidth > cols) cwidth = cols - cx; if (cy + cheight > rows) cheight = rows - cy; /* Draw. */ for (row = cy; row < cy + cheight; ++row) { int col; for (col = cx; col < cx + cwidth; ++col) drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, col, row); } } /* Outline drawing stuff. */ static int linetype = PPMD_LINETYPE_NORMAL; int ppmd_setlinetype(int const type) { int old; old = linetype; linetype = type; return old; } static bool lineclip = TRUE; int ppmd_setlineclip(int const newSetting) { bool previousSetting; previousSetting = lineclip; lineclip = newSetting; return previousSetting; } static void clipEnd0(int const x0, int const y0, int const x1, int const y1, int const cols, int const rows, int * const cx0P, int * const cy0P, bool * const noLineP) { /*---------------------------------------------------------------------------- Given a line that goes from (x0, y0) to (x1, y1), where any of these coordinates may be anywhere in space -- not just in the frame, clip the (x0, y0) end to bring it into the frame. Return the clipped-to location as (*cx0P, *cy0P). Iff this is not possible because the entire line described is outside the frame, return *nolineP == true. The frame is 'cols' columns starting at 0, by 'rows' rows starting at 0. -----------------------------------------------------------------------------*/ int cx0, cy0; bool noLine; cx0 = x0; /* initial value */ cy0 = y0; /* initial value */ noLine = FALSE; /* initial value */ /* Clip End 0 of the line horizontally */ if (cx0 < 0) { if (x1 < 0) noLine = TRUE; else { cy0 = cy0 + (y1 - cy0) * (-cx0) / (x1 - cx0); cx0 = 0; } } else if (cx0 >= cols) { if (x1 >= cols) noLine = TRUE; else { cy0 = cy0 + (y1 - cy0) * (cols - 1 - cx0) / (x1 - cx0); cx0 = cols - 1; } } /* Clip End 0 of the line vertically */ if (cy0 < 0) { if (y1 < 0) noLine = TRUE; else { cx0 = cx0 + (x1 - cx0) * (-cy0) / (y1 - cy0); cy0 = 0; } } else if (cy0 >= rows) { if (y1 >= rows) noLine = TRUE; else { cx0 = cx0 + (x1 - cx0) * (rows - 1 - cy0) / (y1 - cy0); cy0 = rows - 1; } } /* Clipping vertically may have moved the endpoint out of frame horizontally. If so, we know the other endpoint is also out of frame horizontally and the line misses the frame entirely. */ if (cx0 < 0 || cx0 >= cols) { assert(x1 < 0 || x1 >= cols); noLine = TRUE; } *cx0P = cx0; *cy0P = cy0; *noLineP = noLine; } static void clipEnd1(int const x0, int const y0, int const x1, int const y1, int const cols, int const rows, int * const cx1P, int * const cy1P) { /*---------------------------------------------------------------------------- Given a line that goes from (x0, y0) to (x1, y1), where (x0, y0) is within the frame, but (x1, y1) can be anywhere in space, clip the (x1, y1) end to bring it into the frame. Return the clipped-to location as (*cx1P, *cy1P). This is guaranteed to be possible, since we already know at least one point (i.e. (x0, y0)) is in the frame. The frame is 'cols' columns starting at 0, by 'rows' rows starting at 0. -----------------------------------------------------------------------------*/ int cx1, cy1; assert(x0 >= 0 && y0 < cols); assert(y0 >= 0 && y0 < rows); /* Clip End 1 of the line horizontally */ cx1 = x1; /* initial value */ cy1 = y1; /* initial value */ if (cx1 < 0) { /* We know the line isn't vertical, since End 0 is in the frame and End 1 is left of frame. */ cy1 = cy1 + (y0 - cy1) * (-cx1) / (x0 - cx1); cx1 = 0; } else if (cx1 >= cols) { /* We know the line isn't vertical, since End 0 is in the frame and End 1 is right of frame. */ cy1 = cy1 + (y0 - cy1) * (cols - 1 - cx1) / (x0 - cx1); cx1 = cols - 1; } /* Clip End 1 of the line vertically */ if (cy1 < 0) { /* We know the line isn't horizontal, since End 0 is in the frame and End 1 is above frame. */ cx1 = cx1 + (x0 - cx1) * (-cy1) / (y0 - cy1); cy1 = 0; } else if (cy1 >= rows) { /* We know the line isn't horizontal, since End 0 is in the frame and End 1 is below frame. */ cx1 = cx1 + (x0 - cx1) * (rows - 1 - cy1) / (y0 - cy1); cy1 = rows - 1; } *cx1P = cx1; *cy1P = cy1; } static void clipLine(int const x0, int const y0, int const x1, int const y1, int const cols, int const rows, int * const cx0P, int * const cy0P, int * const cx1P, int * const cy1P, bool * const noLineP) { /*---------------------------------------------------------------------------- Clip the line that goes from (x0, y0) to (x1, y1) so that none of it is outside the boundaries of the raster with width 'cols' and height 'rows' The clipped line goes from (*cx0P, *cy0P) to (*cx1P, *cy1P). But if the entire line is outside the boundaries (i.e. we clip the entire line), return *noLineP true and the other values undefined. -----------------------------------------------------------------------------*/ int cx0, cy0, cx1, cy1; /* The line we successively modify. Starts out as the input line and ends up as the output line. */ bool noLine; clipEnd0(x0, y0, x1, y1, cols, rows, &cx0, &cy0, &noLine); if (!noLine) { /* (cx0, cy0) is in the frame: */ assert(cx0 >= 0 && cy0 < cols); assert(cy0 >= 0 && cy0 < rows); clipEnd1(cx0, cy0, x1, y1, cols, rows, &cx1, &cy1); } *cx0P = cx0; *cy0P = cy0; *cx1P = cx1; *cy1P = cy1; *noLineP = noLine; } static void drawShallowLine(ppmd_drawproc drawProc, const void * const clientdata, pixel ** const pixels, int const cols, int const rows, pixval const maxval, int const x0, int const y0, int const x1, int const y1) { /*---------------------------------------------------------------------------- Draw a line that is more horizontal than vertical. Don't clip. Assume the line has distinct start and end points (i.e. it's at least two points). -----------------------------------------------------------------------------*/ /* Loop over X domain. */ long dy, srow; int dx, col, row, prevrow; if (x1 > x0) dx = 1; else dx = -1; dy = (y1 - y0) * DDA_SCALE / abs(x1 - x0); prevrow = row = y0; srow = row * DDA_SCALE + DDA_SCALE / 2; col = x0; for ( ; ; ) { if (linetype == PPMD_LINETYPE_NODIAGS && row != prevrow) { drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, col, prevrow); prevrow = row; } drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, col, row); if (col == x1) break; srow += dy; row = srow / DDA_SCALE; col += dx; } } static void drawSteepLine(ppmd_drawproc drawProc, const void * const clientdata, pixel ** const pixels, int const cols, int const rows, pixval const maxval, int const x0, int const y0, int const x1, int const y1) { /*---------------------------------------------------------------------------- Draw a line that is more vertical than horizontal. Don't clip. Assume the line has distinct start and end points (i.e. it's at least two points). -----------------------------------------------------------------------------*/ /* Loop over Y domain. */ long dx, scol; int dy, col, row, prevcol; if (y1 > y0) dy = 1; else dy = -1; dx = (x1 - x0) * DDA_SCALE / abs(y1 - y0); row = y0; prevcol = col = x0; scol = col * DDA_SCALE + DDA_SCALE / 2; for ( ; ; ) { if (linetype == PPMD_LINETYPE_NODIAGS && col != prevcol) { drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, prevcol, row); prevcol = col; } drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, col, row); if (row == y1) break; row += dy; scol += dx; col = scol / DDA_SCALE; } } void ppmd_line(pixel ** const pixels, int const cols, int const rows, pixval const maxval, int const x0, int const y0, int const x1, int const y1, ppmd_drawproc drawProc, const void * const clientdata) { int cx0, cy0, cx1, cy1; bool noLine; /* There's no line left after clipping */ ppmd_validateCoords(cols, rows); ppmd_validateCoords(x0, y0); ppmd_validateCoords(x1, y1); if (lineclip) { clipLine(x0, y0, x1, y1, cols, rows, &cx0, &cy0, &cx1, &cy1, &noLine); } else { cx0 = x0; cy0 = y0; cx1 = x1; cy1 = y1; noLine = FALSE; } if (noLine) { /* Nothing to draw */ } else if (cx0 == cx1 && cy0 == cy1) { /* This line is just a point. Because there aren't two distinct endpoints, we have a special case. */ drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, cx0, cy0); } else { /* Draw, using a simple DDA. */ if (abs(cx1 - cx0) > abs(cy1 - cy0)) drawShallowLine(drawProc, clientdata, pixels, cols, rows, maxval, cx0, cy0, cx1, cy1); else drawSteepLine(drawProc, clientdata, pixels, cols, rows, maxval, cx0, cy0, cx1, cy1); } } #define SPLINE_THRESH 3 void ppmd_spline3(pixel ** const pixels, int const cols, int const rows, pixval const maxval, int const x0, int const y0, int const x1, int const y1, int const x2, int const y2, ppmd_drawproc drawProc, const void * const clientdata) { register int xa, ya, xb, yb, xc, yc, xp, yp; xa = ( x0 + x1 ) / 2; ya = ( y0 + y1 ) / 2; xc = ( x1 + x2 ) / 2; yc = ( y1 + y2 ) / 2; xb = ( xa + xc ) / 2; yb = ( ya + yc ) / 2; xp = ( x0 + xb ) / 2; yp = ( y0 + yb ) / 2; if ( abs( xa - xp ) + abs( ya - yp ) > SPLINE_THRESH ) ppmd_spline3( pixels, cols, rows, maxval, x0, y0, xa, ya, xb, yb, drawProc, clientdata ); else ppmd_line( pixels, cols, rows, maxval, x0, y0, xb, yb, drawProc, clientdata); xp = ( x2 + xb ) / 2; yp = ( y2 + yb ) / 2; if ( abs( xc - xp ) + abs( yc - yp ) > SPLINE_THRESH ) ppmd_spline3( pixels, cols, rows, maxval, xb, yb, xc, yc, x2, y2, drawProc, clientdata ); else ppmd_line( pixels, cols, rows, maxval, xb, yb, x2, y2, drawProc, clientdata ); } void ppmd_polyspline(pixel ** const pixels, int const cols, int const rows, pixval const maxval, int const x0, int const y0, int const nc, int * const xc, int * const yc, int const x1, int const y1, ppmd_drawproc drawProc, const void * const clientdata) { register int i, x, y, xn, yn; x = x0; y = y0; for ( i = 0; i < nc - 1; ++i ) { xn = ( xc[i] + xc[i + 1] ) / 2; yn = ( yc[i] + yc[i + 1] ) / 2; ppmd_spline3( pixels, cols, rows, maxval, x, y, xc[i], yc[i], xn, yn, drawProc, clientdata ); x = xn; y = yn; } ppmd_spline3( pixels, cols, rows, maxval, x, y, xc[nc - 1], yc[nc - 1], x1, y1, drawProc, clientdata ); } void ppmd_spline4(pixel ** const pixels, int const cols, int const rows, pixval const maxval, int const x0, int const y0, int const x1, int const y1, int const x2, int const y2, int const x3, int const y3, ppmd_drawproc drawproc, const void * const clientdata) { pm_error("ppmd_spline4() has not been written yet!"); } void ppmd_circle(pixel ** const pixels, int const cols, int const rows, pixval const maxval, int const cx, int const cy, int const radius, ppmd_drawproc drawProc, const void * const clientdata) { int x0, y0, x, y, prevx, prevy, nopointsyet; long sx, sy, e; if (radius < 0) pm_error("Error drawing circle. Radius must be positive: %d", radius); else if (radius == 0) return; else if (radius >= DDA_SCALE) pm_error("Error drawing circle. Radius too large: %d", radius); ppmd_validateCoords(cx + radius, cy + radius); ppmd_validateCoords(cx - radius, cy - radius); x0 = x = radius; y0 = y = 0; sx = x * DDA_SCALE + DDA_SCALE / 2; sy = y * DDA_SCALE + DDA_SCALE / 2; e = DDA_SCALE / radius; /* If lineclip is on, draw only points within pixmap. Initial point is 3 o'clock. If lineclip is off, "draw" all points (by designated drawproc). */ if ((x + cx >= 0 && x + cx < cols && y + cy >= 0 && y + cy < rows) || !lineclip) drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, x + cx, y + cy); nopointsyet = 1; do { prevx = x; prevy = y; sx += e * sy / DDA_SCALE; sy -= e * sx / DDA_SCALE; x = sx / DDA_SCALE; y = sy / DDA_SCALE; if (x != prevx || y != prevy) { nopointsyet = 0; if ((x + cx >= 0 && x + cx < cols && y + cy >= 0 && y + cy < rows) || !lineclip) drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, x + cx, y + cy); } } while (nopointsyet || x != x0 || y != y0); } /* Arbitrary fill stuff. */ typedef struct { int x; int y; int edge; } coord; typedef struct fillobj { int n; int size; int curedge; int segstart; int ydir; int startydir; coord * coords; } fillobj; #define SOME 1000 static int oldclip; struct fillobj * ppmd_fill_create(void) { fillobj * fillObjP; MALLOCVAR(fillObjP); if (fillObjP == NULL) pm_error("out of memory allocating a fillhandle"); fillObjP->n = 0; fillObjP->size = SOME; MALLOCARRAY(fillObjP->coords, fillObjP->size); if (fillObjP->coords == NULL) pm_error("out of memory allocating a fillhandle"); fillObjP->curedge = 0; /* Turn off line clipping. */ /* UGGH! We must eliminate this global variable */ oldclip = ppmd_setlineclip(0); return fillObjP; } char * ppmd_fill_init(void) { /*---------------------------------------------------------------------------- Backward compatibility interface. This is what was used before ppmd_fill_create() existed. Note that old programs treat a fill handle as a pointer to char rather than a pointer to fillObj, and backward compatibility depends upon the fact that these are implemented as identical types (an address). -----------------------------------------------------------------------------*/ return (char *)ppmd_fill_create(); } void ppmd_fill_destroy(struct fillobj * fillObjP) { free(fillObjP->coords); free(fillObjP); } void ppmd_fill_drawproc(pixel** const pixels, int const cols, int const rows, pixval const maxval, int const x, int const y, const void * const clientdata) { fillobj * fh; coord * cp; coord * ocp; fh = (fillobj*) clientdata; if (fh->n > 0) { /* If these are the same coords we saved last time, don't bother. */ ocp = &(fh->coords[fh->n - 1]); if ( x == ocp->x && y == ocp->y ) return; } /* Ok, these are new; check if there's room for two more coords. */ if (fh->n + 1 >= fh->size) { fh->size += SOME; REALLOCARRAY(fh->coords, fh->size); if (fh->coords == NULL) pm_error( "out of memory enlarging a fillhandle" ); ocp = &(fh->coords[fh->n - 1]); } /* Check for extremum and set the edge number. */ if (fh->n == 0) { /* Start first segment. */ fh->segstart = fh->n; fh->ydir = 0; fh->startydir = 0; } else { int dx, dy; dx = x - ocp->x; dy = y - ocp->y; if (dx < -1 || dx > 1 || dy < -1 || dy > 1) { /* Segment break. Close off old one. */ if (fh->startydir != 0 && fh->ydir != 0) if (fh->startydir == fh->ydir) { /* Oops, first edge and last edge are the same. Renumber the first edge in the old segment. */ const coord * const fcpLast= &(fh->coords[fh->n -1]); coord * fcp; int oldedge; fcp = &(fh->coords[fh->segstart]); oldedge = fcp->edge; for (; fcp <= fcpLast && fcp->edge == oldedge ; ++fcp) fcp->edge = ocp->edge; } /* And start new segment. */ ++fh->curedge; fh->segstart = fh->n; fh->ydir = 0; fh->startydir = 0; } else { /* Segment continues. */ if (dy != 0) { if (fh->ydir != 0 && fh->ydir != dy) { /* Direction changed. Insert a fake coord, old position but new edge number. */ ++fh->curedge; cp = &fh->coords[fh->n]; cp->x = ocp->x; cp->y = ocp->y; cp->edge = fh->curedge; ++fh->n; } fh->ydir = dy; if (fh->startydir == 0) fh->startydir = dy; } } } /* Save this coord. */ cp = &fh->coords[fh->n]; cp->x = x; cp->y = y; cp->edge = fh->curedge; ++fh->n; } #ifndef LITERAL_FN_DEF_MATCH static qsort_comparison_fn yx_compare; #endif static int yx_compare(const void * const c1Arg, const void * const c2Arg) { const coord * const c1P = c1Arg; const coord * const c2P = c2Arg; int retval; if (c1P->y > c2P->y) retval = 1; else if (c1P->y < c2P->y) retval = -1; else if (c1P->x > c2P->x) retval = 1; else if (c1P->x < c2P->x) retval = -1; else retval = 0; return retval; } void ppmd_fill(pixel ** const pixels, int const cols, int const rows, pixval const maxval, struct fillobj * const fh, ppmd_drawproc drawProc, const void * const clientdata) { int pedge; int i, edge, lx, rx, py; coord * cp; bool eq; bool leftside; /* Close off final segment. */ if (fh->n > 0 && fh->startydir != 0 && fh->ydir != 0) { if (fh->startydir == fh->ydir) { /* Oops, first edge and last edge are the same. */ coord * fcp; const coord * const fcpLast = & (fh->coords[fh->n - 1]); int lastedge, oldedge; lastedge = fh->coords[fh->n - 1].edge; fcp = &(fh->coords[fh->segstart]); oldedge = fcp->edge; for ( ; fcp<=fcpLast && fcp->edge == oldedge; ++fcp ) fcp->edge = lastedge; } } /* Restore clipping now. */ ppmd_setlineclip(oldclip); /* Sort the coords by Y, secondarily by X. */ qsort((char*) fh->coords, fh->n, sizeof(coord), yx_compare); /* Find equal coords with different edge numbers, and swap if necessary. */ edge = -1; for (i = 0; i < fh->n; ++i) { cp = &fh->coords[i]; if (i > 1 && eq && cp->edge != edge && cp->edge == pedge) { /* Swap .-1 and .-2. */ coord t; t = fh->coords[i-1]; fh->coords[i-1] = fh->coords[i-2]; fh->coords[i-2] = t; } if (i > 0) { if (cp->x == lx && cp->y == py) { eq = TRUE; if (cp->edge != edge && cp->edge == pedge) { /* Swap . and .-1. */ coord t; t = *cp; *cp = fh->coords[i-1]; fh->coords[i-1] = t; } } else eq = FALSE; } lx = cp->x; py = cp->y; pedge = edge; edge = cp->edge; } /* Ok, now run through the coords filling spans. */ for (i = 0; i < fh->n; ++i) { cp = &fh->coords[i]; if (i == 0) { lx = rx = cp->x; py = cp->y; edge = cp->edge; leftside = TRUE; } else { if (cp->y != py) { /* Row changed. Emit old span and start a new one. */ ppmd_filledrectangle( pixels, cols, rows, maxval, lx, py, rx - lx + 1, 1, drawProc, clientdata); lx = rx = cp->x; py = cp->y; edge = cp->edge; leftside = TRUE; } else { if (cp->edge == edge) { /* Continuation of side. */ rx = cp->x; } else { /* Edge changed. Is it a span? */ if (leftside) { rx = cp->x; leftside = FALSE; } else { /* Got a span to fill. */ ppmd_filledrectangle( pixels, cols, rows, maxval, lx, py, rx - lx + 1, 1, drawProc, clientdata); lx = rx = cp->x; leftside = TRUE; } edge = cp->edge; } } } } } /* Table used to look up sine of angles from 0 through 90 degrees. The value returned is the sine * 65536. Symmetry is used to obtain sine and cosine for arbitrary angles using this table. */ static long sintab[] = { 0, 1143, 2287, 3429, 4571, 5711, 6850, 7986, 9120, 10252, 11380, 12504, 13625, 14742, 15854, 16961, 18064, 19160, 20251, 21336, 22414, 23486, 24550, 25606, 26655, 27696, 28729, 29752, 30767, 31772, 32768, 33753, 34728, 35693, 36647, 37589, 38521, 39440, 40347, 41243, 42125, 42995, 43852, 44695, 45525, 46340, 47142, 47929, 48702, 49460, 50203, 50931, 51643, 52339, 53019, 53683, 54331, 54963, 55577, 56175, 56755, 57319, 57864, 58393, 58903, 59395, 59870, 60326, 60763, 61183, 61583, 61965, 62328, 62672, 62997, 63302, 63589, 63856, 64103, 64331, 64540, 64729, 64898, 65047, 65176, 65286, 65376, 65446, 65496, 65526, 65536 }; static int extleft, exttop, extright, extbottom; /* To accumulate extents */ /* LINTLIBRARY */ /* ISIN -- Return sine of an angle in integral degrees. The value returned is 65536 times the sine. */ #if __STDC__ static long isin(int deg) #else static long isin(deg) int deg; #endif { /* Domain reduce to 0 to 360 degrees. */ if (deg < 0) { deg = (360 - ((- deg) % 360)) % 360; } else if (deg >= 360) { deg = deg % 360; } /* Now look up from table according to quadrant. */ if (deg <= 90) { return sintab[deg]; } else if (deg <= 180) { return sintab[180 - deg]; } else if (deg <= 270) { return -sintab[deg - 180]; } return -sintab[360 - deg]; } /* ICOS -- Return cosine of an angle in integral degrees. The value returned is 65536 times the cosine. */ #if __STDC__ static long icos(int deg) #else static long icos(deg) int deg; #endif { return isin(deg + 90); } #define SCHAR(x) (u = (x), (((u) & 0x80) ? ((u) | (-1 ^ 0xFF)) : (u))) #define Scalef 21 /* Font design size */ #define Descend 9 /* Descender offset */ static void drawGlyph(const struct ppmd_glyph * const glyphP, int * const xP, int const y, pixel ** const pixels, unsigned int const cols, unsigned int const rows, pixval const maxval, int const height, int const xpos, int const ypos, long const rotcos, long const rotsin, ppmd_drawproc drawProc, const void * const clientdata ) { /*---------------------------------------------------------------------------- *xP is the column number of the left side of the glyph in the output upon entry, and we update it to the left side of the next glyph. 'y' is the row number of either the top or the bottom of the glyph (I can't tell which right now) in the output. -----------------------------------------------------------------------------*/ struct penpos penPos; unsigned int commandNum; int x; int u; /* Used by the SCHAR macro */ x = *xP; /* initial value */ x -= SCHAR(glyphP->header.skipBefore); penPos.x = x; penPos.y = y; for (commandNum = 0; commandNum < glyphP->header.commandCount; ++commandNum) { const struct ppmd_glyphCommand * const commandP = &glyphP->commandList[commandNum]; switch (commandP->verb) { case CMD_NOOP: break; case CMD_DRAWLINE: { int const nx = x + SCHAR(commandP->x); int const ny = y + SCHAR(commandP->y); int mx1, my1, mx2, my2; int tx1, ty1, tx2, ty2; /* Note that up until this moment we've been working in an arbitrary model co-ordinate system with fixed size and no rotation. Before drawing the stroke, transform to viewing co-ordinates to honour the height and angle specifications. */ mx1 = (penPos.x * height) / Scalef; my1 = ((penPos.y - Descend) * height) / Scalef; mx2 = (nx * height) / Scalef; my2 = ((ny - Descend) * height) / Scalef; tx1 = xpos + (mx1 * rotcos - my1 * rotsin) / 65536; ty1 = ypos + (mx1 * rotsin + my1 * rotcos) / 65536; tx2 = xpos + (mx2 * rotcos - my2 * rotsin) / 65536; ty2 = ypos + (mx2 * rotsin + my2 * rotcos) / 65536; ppmd_validateCoords(tx1, ty1); ppmd_validateCoords(tx2, ty2); ppmd_line(pixels, cols, rows, maxval, tx1, ty1, tx2, ty2, drawProc, clientdata); penPos.x = nx; penPos.y = ny; } break; case CMD_MOVEPEN: penPos.x = x + SCHAR(commandP->x); penPos.y = y + SCHAR(commandP->y); break; } } x += glyphP->header.skipAfter; *xP = x; } /* PPMD_TEXT -- Draw the zero-terminated string s, with its baseline starting at point (x, y), inclined by angle degrees to the X axis, with letters height pixels high (descenders will extend below the baseline). The supplied drawproc and cliendata are passed to ppmd_line which performs the actual drawing. */ void ppmd_text(pixel** const pixels, int const cols, int const rows, pixval const maxval, int const xpos, int const ypos, int const height, int const angle, const char * const sArg, ppmd_drawproc drawProc, const void * const clientdata) { const struct ppmd_font * const fontP = ppmd_get_font(); long rotsin, rotcos; int x, y; const char * s; ppmd_validateCoords(xpos, ypos); x = y = 0; rotsin = isin(-angle); rotcos = icos(-angle); s = sArg; while (*s) { unsigned char const ch = *s++; if (ch >= fontP->header.firstCodePoint && ch < fontP->header.firstCodePoint + fontP->header.characterCount) { const struct ppmd_glyph * const glyphP = &fontP->glyphTable[ch - fontP->header.firstCodePoint]; ppmd_validateCoords(x, y); drawGlyph(glyphP, &x, y, pixels, cols, rows, maxval, height, xpos, ypos, rotcos, rotsin, drawProc, clientdata); } else if (ch == '\n') { /* Move to the left edge of the next line down */ y += Scalef + Descend; x = 0; } } } /* EXTENTS_DRAWPROC -- Drawproc which just accumulates the extents rectangle bounding the text. */ static void extents_drawproc (pixel** const pixels, int const cols, int const rows, pixval const maxval, int const x, int const y, const void * const clientdata) { extleft = MIN(extleft, x); exttop = MIN(exttop, y); extright = MAX(extright, x); extbottom = MAX(extbottom, y); } /* PPMD_TEXT_BOX -- Calculate extents rectangle for a given piece of text. For most applications where extents are needed, angle should be zero to obtain the unrotated extents. If you need the extents box for post-rotation text, however, you can set angle nonzero and it will be calculated correctly. */ void ppmd_text_box(int const height, int const angle, const char * const s, int * const left, int * const top, int * const right, int * const bottom) { extleft = 32767; exttop = 32767; extright = -32767; extbottom = -32767; ppmd_text(NULL, 32767, 32767, 255, 1000, 1000, height, angle, s, extents_drawproc, NULL); *left = extleft - 1000; *top = exttop - 1000; *right = extright - 1000; *bottom = extbottom - 1000; }