/*
** Copyright (c) 2015 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the Simplified BSD License (also
** known as the "2-Clause License" or "FreeBSD License".)
** This program is distributed in the hope that it will be useful,
** but without any warranty; without even the implied warranty of
** merchantability or fitness for a particular purpose.
**
** Author contact information:
** drh@hwaci.com
** http://www.hwaci.com/drh/
**
*******************************************************************************
**
** This file contains code for generating pie charts on web pages.
**
*/
#include "config.h"
#include "piechart.h"
#include <math.h>
#ifndef M_PI
# define M_PI 3.1415926535897932385
#endif
/*
** Return an RGB color name given HSV values. The HSV values
** must each be between between 0 and 255. The string
** returned is held in a static buffer and is overwritten
** on each call.
*/
const char *rgbName(unsigned char h, unsigned char s, unsigned char v){
static char zColor[8];
unsigned char A, B, C, r, g, b;
unsigned int i, m;
if( s==0 ){
r = g = b = v;
}else{
i = (h*6)/256;
m = (h*6)&0xff;
A = v*(256-s)/256;
B = v*(65536-s*m)/65536;
C = v*(65536-s*(256-m))/65536;
@ <!-- hsv=%d(h),%d(s),%d(v) i=%d(i) m=%d(m) ABC=%d(A),%d(B),%d(C) -->
switch( i ){
case 0: r=v; g=C; b=A; break;
case 1: r=B; g=v; b=A; break;
case 2: r=A; g=v; b=C; break;
case 3: r=A; g=B; b=v; break;
case 4: r=C; g=A; b=v; break;
default: r=v; g=A; b=B; break;
}
}
sqlite3_snprintf(sizeof(zColor),zColor,"#%02x%02x%02x",r,g,b);
return zColor;
}
/*
** Flags that can be passed into the pie-chart generator
*/
#if INTERFACE
#define PIE_OTHER 0x0001 /* No wedge less than 1/60th of the circle */
#define PIE_CHROMATIC 0x0002 /* Wedge colors are in chromatic order */
#define PIE_PERCENT 0x0004 /* Add "(XX%)" marks on each label */
#endif
/*
** A pie-chart wedge label
*/
struct WedgeLabel {
double rCos, rSin; /* Sine and Cosine of center angle of wedge */
char *z; /* Label to draw on this wedge */
};
typedef struct WedgeLabel WedgeLabel;
/*
** Comparison callback for qsort() to sort labels in order of increasing
** distance above and below the horizontal centerline.
*/
static int wedgeCompare(const void *a, const void *b){
const WedgeLabel *pA = (const WedgeLabel*)a;
const WedgeLabel *pB = (const WedgeLabel*)b;
double rA = fabs(pA->rCos);
double rB = fabs(pB->rCos);
if( rA<rB ) return -1;
if( rA>rB ) return +1;
return 0;
}
/*
** Output HTML that will render a pie chart using data from
** the PIECHART temporary table.
**
** The schema for the PIECHART table should be:
**
** CREATE TEMP TABLE piechart(amt REAL, label TEXT);
*/
void piechart_render(int width, int height, unsigned int pieFlags){
Stmt q;
double cx, cy; /* center of the pie */
double r, r2; /* Radius of the pie */
double x1,y1; /* Start of the slice */
double x2,y2; /* End of the slice */
double x3,y3; /* Middle point of the slice */
double x4,y4; /* End of line extending from x3,y3 */
double x5,y5; /* Text anchor */
double d1; /* radius to x4,y4 */
const char *zAnc; /* Anchor point for text */
double a1 = 0.0; /* Angle for first edge of slice */
double a2; /* Angle for second edge */
double a3; /* Angle at middle of slice */
unsigned char h; /* Hue */
const char *zClr; /* Color */
int l; /* Large arc flag */
int j; /* Wedge number */
double rTotal; /* Total piechart.amt */
double rTooSmall; /* Sum of pieChart.amt entries less than 1/60th */
int nTotal; /* Total number of entries in piechart */
int nTooSmall; /* Number of pieChart.amt entries less than 1/60th */
const char *zFg; /* foreground color for lines and text */
int nWedgeAlloc = 0; /* Slots allocated for aWedge[] */
int nWedge = 0; /* Slots used for aWedge[] */
WedgeLabel *aWedge = 0; /* Labels */
double rUprRight; /* Floor for next label in the upper right quadrant */
double rUprLeft; /* Floor for next label in the upper left quadrant */
double rLwrRight; /* Ceiling for label in the lower right quadrant */
double rLwrLeft; /* Ceiling for label in the lower left quadrant */
int i; /* Loop counter looping over wedge labels */
# define SATURATION 128
# define VALUE 192
# define OTHER_CUTOFF 90.0
# define TEXT_HEIGHT 15.0
cx = 0.5*width;
cy = 0.5*height;
r2 = cx<cy ? cx : cy;
r = r2 - 80.0;
if( r<0.33333*r2 ) r = 0.33333*r2;
h = 0;
zFg = skin_detail_boolean("white-foreground") ? "white" : "black";
db_prepare(&q, "SELECT sum(amt), count(*) FROM piechart");
if( db_step(&q)!=SQLITE_ROW ) return;
rTotal = db_column_double(&q, 0);
nTotal = db_column_int(&q, 1);
db_finalize(&q);
rTooSmall = 0.0;
nTooSmall = 0;
if( (pieFlags & PIE_OTHER)!=0 && nTotal>1 ){
db_prepare(&q, "SELECT sum(amt), count(*) FROM piechart WHERE amt<:amt");
db_bind_double(&q, ":amt", rTotal/OTHER_CUTOFF);
if( db_step(&q)==SQLITE_ROW ){
rTooSmall = db_column_double(&q, 0);
nTooSmall = db_column_double(&q, 1);
}
db_finalize(&q);
}
if( nTooSmall>1 ){
db_prepare(&q, "SELECT amt, label FROM piechart WHERE amt>=:limit"
" UNION ALL SELECT %.17g, '%d others';",
rTooSmall, nTooSmall);
db_bind_double(&q, ":limit", rTotal/OTHER_CUTOFF);
nTotal += 1 - nTooSmall;
}else{
db_prepare(&q, "SELECT amt, label FROM piechart");
}
if( nTotal<=10 ) pieFlags |= PIE_CHROMATIC;
for(j=0; db_step(&q)==SQLITE_ROW; j++){
double x = db_column_double(&q,0)/rTotal;
const char *zLbl = db_column_text(&q,1);
/* @ <!-- x=%g(x) zLbl="%h(zLbl)" h=%d(h) --> */
if( x<=0.0 ) continue;
x1 = cx + sin(a1)*r;
y1 = cy - cos(a1)*r;
a2 = a1 + x*2.0*M_PI;
x2 = cx + sin(a2)*r;
y2 = cy - cos(a2)*r;
a3 = 0.5*(a1+a2);
if( nWedge+1>nWedgeAlloc ){
nWedgeAlloc = nWedgeAlloc*2 + 40;
aWedge = fossil_realloc(aWedge, sizeof(aWedge[0])*nWedgeAlloc);
}
if( pieFlags & PIE_PERCENT ){
int pct = (int)(x*100.0 + 0.5);
aWedge[nWedge].z = mprintf("%s (%d%%)", zLbl, pct);
}else{
aWedge[nWedge].z = fossil_strdup(zLbl);
}
aWedge[nWedge].rSin = sin(a3);
aWedge[nWedge].rCos = cos(a3);
nWedge++;
if( (j&1)==0 || (pieFlags & PIE_CHROMATIC)!=0 ){
h = 256*j/nTotal;
}else if( j+2<nTotal ){
h = 256*(j+2)/nTotal;
}else{
h = 256*((j+2+(nTotal&1))%nTotal)/nTotal;
}
zClr = rgbName(h,SATURATION,VALUE);
l = x>=0.5;
a1 = a2;
@ <path class='piechartWedge'
@ stroke="black" stroke-width="1" fill="%s(zClr)"
@ d='M%g(cx),%g(cy)L%g(x1),%g(y1)A%g(r),%g(r) 0 %d(l),1 %g(x2),%g(y2)z'/>
}
qsort(aWedge, nWedge, sizeof(aWedge[0]), wedgeCompare);
rUprLeft = height;
rLwrLeft = 0;
rUprRight = height;
rLwrRight = 0;
d1 = r*1.1;
for(i=0; i<nWedge; i++){
WedgeLabel *p = &aWedge[i];
x3 = cx + p->rSin*r;
y3 = cy - p->rCos*r;
x4 = cx + p->rSin*d1;
y4 = cy - p->rCos*d1;
if( y4<=cy ){
if( x4>=cx ){
if( y4>rUprRight ){
y4 = rUprRight;
}
rUprRight = y4 - TEXT_HEIGHT;
}else{
if( y4>rUprLeft ){
y4 = rUprLeft;
}
rUprLeft = y4 - TEXT_HEIGHT;
}
}else{
if( x4>=cx ){
if( y4<rLwrRight ){
y4 = rLwrRight;
}
rLwrRight = y4 + TEXT_HEIGHT;
}else{
if( y4<rLwrLeft ){
y4 = rLwrLeft;
}
rLwrLeft = y4 + TEXT_HEIGHT;
}
}
if( x4<cx ){
x5 = x4 - 1.0;
zAnc = "end";
}else{
x5 = x4 + 1.0;
zAnc = "start";
}
y5 = y4 - 3.0 + 6.0*(1.0 - p->rCos);
@ <line stroke-width='1' stroke='%s(zFg)' class='piechartLine'
@ x1='%g(x3)' y1='%g(y3)' x2='%g(x4)' y2='%g(y4)'/>
@ <text text-anchor="%s(zAnc)" fill='%s(zFg)' class="piechartLabel"
@ x='%g(x5)' y='%g(y5)'>%h(p->z)</text>
fossil_free(p->z);
}
db_finalize(&q);
fossil_free(aWedge);
}
/*
** WEBPAGE: test-piechart
**
** Generate a pie-chart based on data input from a form.
*/
void piechart_test_page(void){
const char *zData;
Stmt ins;
int n = 0;
int width;
int height;
int i, j;
login_check_credentials();
style_header("Pie Chart Test");
db_multi_exec("CREATE TEMP TABLE piechart(amt REAL, label TEXT);");
db_prepare(&ins, "INSERT INTO piechart(amt,label) VALUES(:amt,:label)");
zData = PD("data","");
width = atoi(PD("width","800"));
height = atoi(PD("height","400"));
i = 0;
while( zData[i] ){
double rAmt;
char *zLabel;
while( fossil_isspace(zData[i]) ){ i++; }
j = i;
while( fossil_isdigit(zData[j]) ){ j++; }
if( zData[j]=='.' ){
j++;
while( fossil_isdigit(zData[j]) ){ j++; }
}
if( i==j ) break;
rAmt = atof(&zData[i]);
i = j;
while( zData[i]==',' || fossil_isspace(zData[i]) ){ i++; }
n++;
zLabel = mprintf("label%02d-%g", n, rAmt);
db_bind_double(&ins, ":amt", rAmt);
db_bind_text(&ins, ":label", zLabel);
db_step(&ins);
db_reset(&ins);
fossil_free(zLabel);
}
db_finalize(&ins);
if( n>1 ){
@ <svg width=%d(width) height=%d(height) style="border:1px solid #d3d3d3;">
piechart_render(width,height, PIE_OTHER|PIE_PERCENT);
@ </svg>
@ <hr />
}
@ <form method="POST" action='%R/test-piechart'>
@ <p>Comma-separated list of slice widths:<br />
@ <input type='text' name='data' size='80' value='%h(zData)'/><br />
@ Width: <input type='text' size='8' name='width' value='%d(width)'/>
@ Height: <input type='text' size='8' name='height' value='%d(height)'/><br />
@ <input type='submit' value='Draw The Pie Chart'/>
@ </form>
@ <p>Interesting test cases:
@ <ul>
@ <li> <a href='test-piechart?data=44,2,2,2,2,2,3,2,2,2,2,2,44'>Case 1</a>
@ <li> <a href='test-piechart?data=2,2,2,2,2,44,44,2,2,2,2,2'>Case 2</a>
@ <li> <a href='test-piechart?data=20,2,2,2,2,2,2,2,2,2,2,80'>Case 3</a>
@ <li> <a href='test-piechart?data=80,2,2,2,2,2,2,2,2,2,2,20'>Case 4</a>
@ <li> <a href='test-piechart?data=2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2'>Case 5</a>
@ </ul>
style_footer();
}