/* ** ** 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; }; struct rectangle { /* ((0,0),(0,0)) means empty. */ /* 'lr' is guaranteed not to be left of or above 'ul' */ struct penpos ul; struct penpos lr; }; static struct rectangle const emptyRectangle = { {0, 0}, {0, 0}, }; static ppmd_point makePoint(int const x, int const y) { return ppmd_makePoint(x, y); } static ppmd_point middlePoint(ppmd_point const a, ppmd_point const b) { ppmd_point retval; retval.x = (a.x + b.x) / 2; retval.y = (a.y + b.y) / 2; return retval; } static bool pointsEqual(ppmd_point const a, ppmd_point const b) { return a.x == b.x && a.y == b.y; } static bool pointIsWithinBounds(ppmd_point const p, unsigned int const cols, unsigned int const rows) { return (p.x >= 0 && p.x < cols && p.y >= 0 && p.y < rows); } static ppmd_point vectorSum(ppmd_point const a, ppmd_point const b) { return makePoint(a.x + b.x, a.y + b.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. */ void ppmd_validateCoord(int const c) { if (c < -PPMD_MAXCOORD || c > PPMD_MAXCOORD) pm_error("Coordinate out of bounds: %d", c); } void ppmd_validatePoint(ppmd_point const p) { if (p.x < -PPMD_MAXCOORD || p.x > PPMD_MAXCOORD) pm_error("x coordinate of (%d, %d) out of bounds", p.x, p.y); if (p.y < -PPMD_MAXCOORD || p.y > PPMD_MAXCOORD) pm_error("y coordinate of (%d, %d) out of bounds", p.x, p.y); } static void drawPoint(ppmd_drawprocp drawproc, const void * const clientdata, pixel ** const pixels, int const cols, int const rows, pixval const maxval, ppmd_point const p) { /*---------------------------------------------------------------------------- Draw a single point, assuming that it is within the bounds of the image. -----------------------------------------------------------------------------*/ if (drawproc == PPMD_NULLDRAWPROC) { const pixel * const pixelP = clientdata; assert(p.x >= 0); assert(p.x < cols); assert(p.y >= 0); assert(p.y < rows); pixels[p.y][p.x] = *pixelP; } else drawproc(pixels, cols, rows, maxval, p, clientdata); } struct drawProcXY { ppmd_drawproc * drawProc; const void * clientData; }; static struct drawProcXY makeDrawProcXY(ppmd_drawproc * const drawProc, const void * const clientData) { struct drawProcXY retval; retval.drawProc = drawProc; retval.clientData = clientData; return retval; } static ppmd_drawprocp drawProcPointXY; static void drawProcPointXY(pixel ** const pixels, unsigned int const cols, unsigned int const rows, pixval const maxval, ppmd_point const p, const void * const clientdata) { const struct drawProcXY * const xyP = clientdata; if (xyP->drawProc == PPMD_NULLDRAWPROC) drawPoint(PPMD_NULLDRAWPROC, xyP->clientData, pixels, cols, rows, maxval, p); else xyP->drawProc(pixels, cols, rows, maxval, p.x, p.y, xyP->clientData); } void ppmd_point_drawprocp(pixel ** const pixels, unsigned int const cols, unsigned int const rows, pixval const maxval, ppmd_point const p, const void * const clientdata) { if (p.x >= 0 && p.x < cols && p.y >= 0 && p.y < rows) pixels[p.y][p.x] = *((pixel*)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) { ppmd_point p; p.x = x; p.y = y; ppmd_point_drawprocp(pixels, cols, rows, maxval, p, clientdata); } static void findRectangleIntersection(struct rectangle const rect1, struct rectangle const rect2, struct rectangle * const intersectionP) { /*---------------------------------------------------------------------------- Find the intersection between rectangles 'rect1' and 'rect2'. Return it as *intersectionP. -----------------------------------------------------------------------------*/ struct penpos tentativeUl, tentativeLr; tentativeUl.x = MAX(rect1.ul.x, rect2.ul.x); tentativeUl.y = MAX(rect1.ul.y, rect2.ul.y); tentativeLr.x = MIN(rect1.lr.x, rect2.lr.x); tentativeLr.y = MIN(rect1.lr.y, rect2.lr.y); if (tentativeLr.x <= tentativeUl.x || tentativeLr.y <= tentativeUl.y) { /* No intersection */ *intersectionP = emptyRectangle; } else { intersectionP->ul = tentativeUl; intersectionP->lr = tentativeLr; } } 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) { struct drawProcXY const xy = makeDrawProcXY(drawProc, clientdata); struct rectangle image, request, intersection; unsigned int row; if (width < 0) pm_error("negative width %d passed to ppmd_filledrectangle", width); if (height < 0) pm_error("negative height %d passed to ppmd_filledrectangle", height); if (cols < 0) pm_error("negative image width %d passed to ppmd_filledrectangle", cols); if (rows < 0) pm_error("negative image height %d passed to ppmd_filledrectangle", rows); request.ul.x = x; request.ul.y = y; request.lr.x = x + width; request.lr.y = y + height; image.ul.x = 0; image.ul.y = 0; image.lr.x = cols; image.lr.y = rows; findRectangleIntersection(image, request, &intersection); /* Draw. */ for (row = intersection.ul.y; row < intersection.lr.y; ++row) { unsigned int col; for (col = intersection.ul.x; col < intersection.lr.x; ++col) drawPoint(drawProcPointXY, &xy, pixels, cols, rows, maxval, makePoint(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(ppmd_point const p0, ppmd_point const p1, int const cols, int const rows, ppmd_point * const c0P, bool * const noLineP) { /*---------------------------------------------------------------------------- Given a line that goes from p0 to p1, where any of these coordinates may be anywhere in space -- not just in the frame, clip the p0 end to bring it into the frame. Return the clipped-to location as *c0P. 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. -----------------------------------------------------------------------------*/ ppmd_point c0; bool noLine; c0 = p0; /* initial value */ noLine = FALSE; /* initial value */ /* Clip End 0 of the line horizontally */ if (c0.x < 0) { if (p1.x < 0) noLine = TRUE; else { c0.y = c0.y + (p1.y - c0.y) * (-c0.x) / (p1.x - c0.x); c0.x = 0; } } else if (c0.x >= cols) { if (p1.x >= cols) noLine = TRUE; else { c0.y = c0.y + (p1.y - c0.y) * (cols - 1 - c0.x) / (p1.x - c0.x); c0.x = cols - 1; } } /* Clip End 0 of the line vertically */ if (c0.y < 0) { if (p1.y < 0) noLine = TRUE; else { c0.x = c0.x + (p1.x - c0.x) * (-c0.y) / (p1.y - c0.y); c0.y = 0; } } else if (c0.y >= rows) { if (p1.y >= rows) noLine = TRUE; else { c0.x = c0.x + (p1.x - c0.x) * (rows - 1 - c0.y) / (p1.y - c0.y); c0.y = 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 (c0.x < 0 || c0.x >= cols) { assert(p1.x < 0 || p1.x >= cols); noLine = TRUE; } *c0P = c0; *noLineP = noLine; } static void clipEnd1(ppmd_point const p0, ppmd_point const p1, int const cols, int const rows, ppmd_point * const c1P) { /*---------------------------------------------------------------------------- Given a line that goes from p0 to p1, where p0 is within the frame, but p1 can be anywhere in space, clip the p1 end to bring it into the frame. Return the clipped-to location as *c1P. This is guaranteed to be possible, since we already know at least one point (i.e. p0) is in the frame. The frame is 'cols' columns starting at 0, by 'rows' rows starting at 0. -----------------------------------------------------------------------------*/ ppmd_point c1; /* The current clipped location of p1; we clip it multile times to get the final location. */ /* p0 is in the frame: */ assert(p0.x >= 0 && p0.x < cols); assert(p0.y >= 0 && p0.y < rows); /* Clip End 1 of the line horizontally */ c1 = p1; /* initial value */ if (c1.x < 0) { /* We know the line isn't vertical, since End 0 is in the frame and End 1 is left of frame. */ c1.y = c1.y + (p0.y - c1.y) * (-c1.x) / (p0.x - c1.x); c1.x = 0; } else if (c1.x >= cols) { /* We know the line isn't vertical, since End 0 is in the frame and End 1 is right of frame. */ c1.y = c1.y + (p0.y - c1.y) * (cols - 1 - c1.x) / (p0.x - c1.x); c1.x = cols - 1; } /* Clip End 1 of the line vertically */ if (c1.y < 0) { /* We know the line isn't horizontal, since End 0 is in the frame and End 1 is above frame. */ c1.x = c1.x + (p0.x - c1.x) * (-c1.y) / (p0.y - c1.y); c1.y = 0; } else if (c1.y >= rows) { /* We know the line isn't horizontal, since End 0 is in the frame and End 1 is below frame. */ c1.x = c1.x + (p0.x - c1.x) * (rows - 1 - c1.y) / (p0.y - c1.y); c1.y = rows - 1; } *c1P = c1; } static void clipLine(ppmd_point const p0, ppmd_point const p1, int const cols, int const rows, ppmd_point * const c0P, ppmd_point * const c1P, bool * const noLineP) { /*---------------------------------------------------------------------------- Clip the line that goes from p0 to p1 so that none of it is outside the boundaries of the raster with width 'cols' and height 'rows' The clipped line goes from *c0P to *c1P. But if the entire line is outside the boundaries (i.e. we clip the entire line), return *noLineP true and the other values undefined. -----------------------------------------------------------------------------*/ ppmd_point c0, c1; /* The line we successively modify. Starts out as the input line and ends up as the output line. */ bool noLine; clipEnd0(p0, p1, cols, rows, &c0, &noLine); if (!noLine) { /* p0 is in the frame: */ assert(c0.x >= 0 && c0.x < cols); assert(c0.y >= 0 && c0.y < rows); clipEnd1(c0, p1, cols, rows, &c1); } *c0P = c0; *c1P = c1; *noLineP = noLine; } static void drawShallowLine(ppmd_drawprocp drawProc, const void * const clientdata, pixel ** const pixels, int const cols, int const rows, pixval const maxval, ppmd_point const p0, ppmd_point const p1) { /*---------------------------------------------------------------------------- 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 (p1.x > p0.x) dx = 1; else dx = -1; dy = (p1.y - p0.y) * DDA_SCALE / abs(p1.x - p0.x); prevrow = row = p0.y; srow = row * DDA_SCALE + DDA_SCALE / 2; col = p0.x; for ( ; ; ) { if (linetype == PPMD_LINETYPE_NODIAGS && row != prevrow) { drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, makePoint(col, prevrow)); prevrow = row; } drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, makePoint(col, row)); if (col == p1.x) break; srow += dy; row = srow / DDA_SCALE; col += dx; } } static void drawSteepLine(ppmd_drawprocp drawProc, const void * const clientdata, pixel ** const pixels, int const cols, int const rows, pixval const maxval, ppmd_point const p0, ppmd_point const p1) { /*---------------------------------------------------------------------------- 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 (p1.y > p0.y) dy = 1; else dy = -1; dx = (p1.x - p0.x) * DDA_SCALE / abs(p1.y - p0.y); row = p0.y; prevcol = col = p0.x; scol = col * DDA_SCALE + DDA_SCALE / 2; for ( ; ; ) { if (linetype == PPMD_LINETYPE_NODIAGS && col != prevcol) { drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, makePoint(prevcol, row)); prevcol = col; } drawPoint(drawProc, clientdata, pixels, cols, rows, maxval, makePoint(col, row)); if (row == p1.y) break; row += dy; scol += dx; col = scol / DDA_SCALE; } } void ppmd_linep(pixel ** const pixels, int const cols, int const rows, pixval const maxval, ppmd_point const p0, ppmd_point const p1, ppmd_drawprocp drawProc, const void * const clientdata) { ppmd_point c0, c1; bool noLine; /* There's no line left after clipping */ ppmd_validateCoord(cols); ppmd_validateCoord(rows); ppmd_validatePoint(p0); ppmd_validatePoint(p1); if (lineclip) { clipLine(p0, p1, cols, rows, &c0, &c1, &noLine); } else { c0 = p0; c1 = p1; noLine = FALSE; } if (noLine) { /* Nothing to draw */ } else if (pointsEqual(c0, c1)) { /* 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, c0); } else { /* Draw, using a simple DDA. */ if (abs(c1.x - c0.x) > abs(c1.y - c0.y)) drawShallowLine(drawProc, clientdata, pixels, cols, rows, maxval, c0, c1); else drawSteepLine(drawProc, clientdata, pixels, cols, rows, maxval, c0, c1); } } 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) { struct drawProcXY const xy = makeDrawProcXY(drawProc, clientData); ppmd_linep(pixels, cols, rows, maxval, makePoint(x0, y0), makePoint(x1, y1), drawProcPointXY, &xy); } static unsigned int distanceFromLine(ppmd_point const p, ppmd_point const l0, ppmd_point const l1) { /*---------------------------------------------------------------------------- Compute, sort of, the distance between point 'p' and the line through 'l0' and 'l1'. I don't really know the signficance of this measurement. -----------------------------------------------------------------------------*/ ppmd_point const middle = middlePoint(l0, l1); return (abs(p.x - middle.x) + abs(p.y - middle.y)); } void ppmd_spline3p(pixel ** const pixels, int const cols, int const rows, pixval const maxval, ppmd_point const p0, ppmd_point const ctl, ppmd_point const p1, ppmd_drawprocp drawProc, const void * const clientdata) { static unsigned int const splineThresh = 3; /* The limit of recursion */ if (distanceFromLine(ctl, p0, p1) <= splineThresh) { /* The control point is pretty close to the straight line that joins the endpoints, so we'll just draw a straight line. */ ppmd_linep( pixels, cols, rows, maxval, p0, p1, drawProc, clientdata); } else { /* We want some curvature, so pick a point (b) sort of between the two endpoints and the control point and then draw a spline between each of the endpoints and (b): */ ppmd_point const a = middlePoint(p0, ctl); ppmd_point const c = middlePoint(ctl, p1); ppmd_point const b = middlePoint(a, c); ppmd_spline3p( pixels, cols, rows, maxval, p0, a, b, drawProc, clientdata); ppmd_spline3p( pixels, cols, rows, maxval, b, c, p1, drawProc, clientdata); } } 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) { struct drawProcXY const xy = makeDrawProcXY(drawProc, clientdata); ppmd_spline3p(pixels, cols, rows, maxval, makePoint(x0, y0), makePoint(x1, y1), makePoint(x2, y2), drawProcPointXY, &xy); } void ppmd_polysplinep(pixel ** const pixels, unsigned int const cols, unsigned int const rows, pixval const maxval, ppmd_point const p0, unsigned int const nc, ppmd_point * const c, ppmd_point const p1, ppmd_drawprocp drawProc, const void * const clientdata) { ppmd_point p; unsigned int i; assert(nc > 0); p = p0; for (i = 0; i < nc - 1; ++i) { ppmd_point const n = middlePoint(c[i], c[i+1]); ppmd_spline3p( pixels, cols, rows, maxval, p, c[i], n, drawProc, clientdata); p = n; } ppmd_spline3p( pixels, cols, rows, maxval, p, c[nc - 1], p1, 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) { ppmd_point const p1 = makePoint(x1, y1); ppmd_point const p0 = makePoint(x0, y0); struct drawProcXY const xy = makeDrawProcXY(drawProc, clientdata); ppmd_point p; unsigned int i; p = p0; /* initial value */ assert(nc > 0); for (i = 0; i < nc - 1; ++i) { ppmd_point const n = middlePoint(makePoint(xc[i], yc[i]), makePoint(xc[i+1], yc[i+1])); ppmd_spline3p( pixels, cols, rows, maxval, p, makePoint(xc[i], yc[i]), n, drawProcPointXY, &xy); p = n; } ppmd_spline3p( pixels, cols, rows, maxval, p, makePoint(xc[nc - 1], yc[nc - 1]), p1, drawProcPointXY, &xy); } void ppmd_spline4p(pixel ** const pixels, unsigned int const cols, unsigned int const rows, pixval const maxval, ppmd_point const endPt0, ppmd_point const endPt1, ppmd_point const ctlPt0, ppmd_point const ctlPt1, ppmd_drawprocp drawproc, const void * const clientdata) { /*---------------------------------------------------------------------------- Draw a cubic spline from 'endPt0' to 'endPt1', using 'ctlPt0' and 'ctlPt1' as control points in the classic way: a line through 'endPt0' and 'ctlPt0' is tangent to the curve at 'entPt0' and the length of that line controls "enthusiasm," whatever that is. Same for 'endPt1' and 'ctlPt1'. -----------------------------------------------------------------------------*/ pm_error("ppmd_spline4p() has not been written yet!"); } void ppmd_circlep(pixel ** const pixels, unsigned int const cols, unsigned int const rows, pixval const maxval, ppmd_point const center, unsigned int const radius, ppmd_drawprocp drawProc, const void * const clientData) { /*---------------------------------------------------------------------------- If lineclip mode is on, draw only points within the image. If lineclip is off, "draw" all points (by designated drawproc). Note that the drawproc can't actually draw a point outside the image, but it might maintain state that is affected by imaginary points outside the image. Initial point is 3 o'clock. -----------------------------------------------------------------------------*/ if (radius >= DDA_SCALE) pm_error("Error drawing circle. Radius %d is too large.", radius); ppmd_validateCoord(center.x + radius); ppmd_validateCoord(center.y + radius); ppmd_validateCoord(center.x - radius); ppmd_validateCoord(center.y - radius); if (radius > 0) { long const e = DDA_SCALE / radius; ppmd_point const p0 = makePoint(radius, 0); /* 3 o'clock */ /* The starting point around the circle, assuming (0, 0) center */ ppmd_point p; /* Current drawing position in the circle, assuming (0,0) center */ bool onFirstPoint; bool prevPointExists; ppmd_point prevPoint; /* Previous drawing position, assuming (0, 0) center*/ long sx, sy; /* 'p', scaled by DDA_SCALE */ p = p0; sx = p.x * DDA_SCALE + DDA_SCALE / 2; sy = p.y * DDA_SCALE + DDA_SCALE / 2; onFirstPoint = TRUE; prevPointExists = FALSE; while (onFirstPoint || !pointsEqual(p, p0)) { if (prevPointExists && pointsEqual(p, prevPoint)) { /* We're on the same point we were on last time (we moved less than a point's worth). Just keep moving. */ } else { ppmd_point const imagePoint = vectorSum(center,p); if (!lineclip || pointIsWithinBounds(imagePoint, cols, rows)) drawPoint(drawProc, clientData, pixels, cols, rows, maxval, imagePoint); prevPoint = p; prevPointExists = TRUE; } if (!pointsEqual(p, p0)) onFirstPoint = FALSE; sx += e * sy / DDA_SCALE; sy -= e * sx / DDA_SCALE; p = makePoint(sx / DDA_SCALE, sy / DDA_SCALE); } } } 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) { if (radius < 0) pm_error("Error drawing circle. Radius %d is negative.", radius); else { struct drawProcXY const xy = makeDrawProcXY(drawProc, clientData); ppmd_circlep(pixels, cols, rows, maxval, makePoint(cx, cy), radius, drawProcPointXY, &xy); } } /* Arbitrary fill stuff. */ typedef struct { ppmd_point point; 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_drawprocp(pixel ** const pixels, unsigned int const cols, unsigned int const rows, pixval const maxval, ppmd_point const p, const void * const clientdata) { fillobj * fh; coord * cp; fh = (fillobj*) clientdata; /* If these are the same coords we saved last time, don't bother. */ if (fh->n > 0) { ppmd_point const lastPoint = fh->coords[fh->n - 1].point; if (pointsEqual(p, lastPoint)) return; } /* Ok, these are new; make 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"); } /* 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 { coord * const ocp = &(fh->coords[fh->n - 1]); int dx, dy; dx = p.x - ocp->point.x; dy = p.y - ocp->point.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->point = ocp->point; 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->point = p; cp->edge = fh->curedge; ++fh->n; } 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) { ppmd_fill_drawprocp(pixels, cols, rows, maxval, makePoint(x, y), clientData); } #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; ppmd_point const p1 = c1P->point; ppmd_point const p2 = c2P->point; int retval; if (p1.y > p2.y) retval = 1; else if (p1.y < p2.y) retval = -1; else if (p1.x > p2.x) retval = 1; else if (p1.x < p2.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->point.x == lx && cp->point.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->point.x; py = cp->point.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->point.x; py = cp->point.y; edge = cp->edge; leftside = TRUE; } else { if (cp->point.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->point.x; py = cp->point.y; edge = cp->edge; leftside = TRUE; } else { if (cp->edge == edge) { /* Continuation of side. */ rx = cp->point.x; } else { /* Edge changed. Is it a span? */ if (leftside) { rx = cp->point.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->point.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. */ static long isin(int deg) { /* 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. */ static long icos(int deg) { return isin(deg + 90); } static int twosCompByteValue(unsigned char const c) { /*---------------------------------------------------------------------------- E.g. if 'c' is 0x5, return 5. If 'c' is 0xF0, return -16. -----------------------------------------------------------------------------*/ return (char)c; } static int glyphSkipBefore(const struct ppmd_glyph * const glyphP) { return twosCompByteValue(glyphP->header.skipBefore); } static int glyphWidth(const struct ppmd_glyph * const glyphP) { return twosCompByteValue(glyphP->header.skipAfter) - twosCompByteValue(glyphP->header.skipBefore); } static ppmd_point commandPoint(const struct ppmd_glyphCommand * const commandP) { /*---------------------------------------------------------------------------- Return the point which is the argument of glyph drawing command *commandP. The origin of the coordinate system for this point is the center of the glyph cell and the scale is the scale of the font, so (-10, -10) means the upper left corner of the glyph cell. -----------------------------------------------------------------------------*/ return makePoint(twosCompByteValue(commandP->x), twosCompByteValue(commandP->y)); } #define Scalef 21 /* Font design size */ #define Descend 9 /* Descender offset */ static ppmd_point textPosFromFontPos(ppmd_point const fontPos, ppmd_point const textBoxOrigin, ppmd_point const center, ppmd_point const glyphOrigin, unsigned int const height, long const rotcos, long const rotsin) { /*---------------------------------------------------------------------------- 'fontPos' is a position within a glyph as told by the font definition. It is relative to the center of the glyph, in units of font pixels (1/21 of a glyph cell). We return the position on the canvas of that point. That takes into account where in the text box we are, where the text box is on the canvas, the size of the characters, and the rotation of the text box. -----------------------------------------------------------------------------*/ ppmd_point const ptl = vectorSum(center, fontPos); /* Position relative to the top left of the standard glyph cell */ ppmd_point const pl = vectorSum(glyphOrigin, ptl); /* Position relative to the top left of the whole text box, assuming the text box is horizontal and has font scale. */ ppmd_point const ps = makePoint((pl.x * (int)height) / Scalef, (pl.y * (int)height) / Scalef); /* Same as above, but with the text box its actual size */ ppmd_point const retval = makePoint(textBoxOrigin.x + (ps.x * rotcos - (ps.y-(int)height) * rotsin) / 65536, textBoxOrigin.y + (ps.x * rotsin + (ps.y-(int)height) * rotcos) / 65536); ppmd_validatePoint(retval); return retval; } static void drawGlyph(const struct ppmd_glyph * const glyphP, ppmd_point const glyphOrigin, pixel ** const pixels, unsigned int const cols, unsigned int const rows, pixval const maxval, int const height, ppmd_point const textBoxOrigin, long const rotcos, long const rotsin, ppmd_drawprocp drawProc, const void * const clientdata, unsigned int * const cursorAdvanceP ) { /*---------------------------------------------------------------------------- 'glyphOrigin' is the position relative to the upper left corner of the text box of the upper left corner of this glyph cell. It is in units of font pixels (so you have to scale it by the font size to actual distance on the canvas). We return as *cursorAdvanceP the amount to the right of this glyph cell the next glyph cell on the line (if any) should be. The actual glyph cell may be a little to the left of the nominal position because of kerning. The font says how much to shift the cell left. 'textBoxOrigin' is the left end of the baseline of the top line in the text box, in the coordinate system of the canvas. 'rotcos' and 'rotsin' tell how that text box is rotated with respect to the horizontal on the canvas. 'height' is the height in canvas pixels of a glyph. This is a scale factor to convert font coordinates to canvas coordinates. -----------------------------------------------------------------------------*/ ppmd_point const center = makePoint(-glyphSkipBefore(glyphP), Scalef/2); /* This is what you have to add to the coordinates in a glyph command, which are relative to the center of the glyph, to get coordinates relative to the upper left corner of the glyph */ ppmd_point p; /* Current drawing position within the glyph. Origin is the top left of the glyph cell. Units are font pixels. */ unsigned int commandNum; p = textPosFromFontPos(makePoint(0, 0), textBoxOrigin, center, glyphOrigin, height, rotcos, rotsin); /* initial value */ 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: { ppmd_point const n = textPosFromFontPos(commandPoint(commandP), textBoxOrigin, center, glyphOrigin, height, rotcos, rotsin); ppmd_linep(pixels, cols, rows, maxval, p, n, drawProc, clientdata); p = n; } break; case CMD_MOVEPEN: p = textPosFromFontPos(commandPoint(commandP), textBoxOrigin, center, glyphOrigin, height, rotcos, rotsin); break; } } *cursorAdvanceP = glyphWidth(glyphP); } void ppmd_textp(pixel** const pixels, int const cols, int const rows, pixval const maxval, ppmd_point const pos, int const height, int const angle, const char * const sArg, ppmd_drawprocp drawProc, const void * const clientdata) { /*---------------------------------------------------------------------------- Draw the zero-terminated string 'sArg', with its baseline starting at point 'pos', inclined by 'angle' degrees to the X axis, with letters 'height' pixels high (descenders will extend below the baseline). We pass the supplied drawproc and clientdata to ppmd_linep, which performs the actual drawing. There may be multiple lines of text. The baseline of the topmost line starts at 'pos'. -----------------------------------------------------------------------------*/ const struct ppmd_font * const fontP = ppmd_get_font(); long rotsin, rotcos; ppmd_point p; const char * s; ppmd_validatePoint(pos); p = makePoint(0, 0); rotsin = isin(-angle); rotcos = icos(-angle); for (s = &sArg[0]; *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]; unsigned int cursorAdvance; ppmd_validatePoint(p); drawGlyph(glyphP, p, pixels, cols, rows, maxval, height, pos, rotcos, rotsin, drawProc, clientdata, &cursorAdvance); p.x += cursorAdvance; } else if (ch == '\n') { /* Move to the left edge of the next line down */ p.y += Scalef + Descend; p.x = 0; } } } 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) { struct drawProcXY const xy = makeDrawProcXY(drawProc, clientData); ppmd_textp(pixels, cols, rows, maxval, makePoint(xpos, ypos), height, angle, sArg, drawProcPointXY, &xy); } /* 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; }