/*
** 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>
/*
** 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 */
#endif
/*
** 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 */
int rot; /* Text rotation angle */
double sina3, cosa3; /* sin(a3) and cos(a3) */
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 */
# define SATURATION 128
# define VALUE 192
cx = 0.5*width;
cy = 0.5*height;
r2 = cx<cy ? cx : cy;
r = r2 - 60.0;
if( r<0.33333*r2 ) r = 0.33333*r2;
h = 0;
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/60.0);
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/60.0);
nTotal += 1 - nTooSmall;
}else{
db_prepare(&q, "SELECT amt, label FROM piechart");
}
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);
sina3 = sin(a3);
cosa3 = cos(a3);
x3 = cx + sina3*r;
y3 = cy - cosa3*r;
d1 = r*1.1;
x4 = cx + sina3*d1;
y4 = cy - cosa3*d1;
y5 = y4 - 3.0 + 6.0*(1.0 -cosa3);
rot = ((int)(a3*180/M_PI))%180;
if( a2-a1 > 0.6 ){
rot = 0; /* Never rotate text on fat slices */
}else if( rot<60 ){
rot = (rot - 60)/2;
}else if( rot>120 ){
rot = (rot - 120)/2;
}else{
rot = 0;
}
if( x4<=cx ){
x5 = x4 - 5.0;
zAnc = "end";
}else{
x5 = x4 + 4.0;
zAnc = "start";
}
if( (j&1)==0 || (pieFlags & PIE_CHROMATIC)!=0 ){
h = 256*j/nTotal;
}else{
h = 256*((j+1+nTotal/2)%nTotal)/nTotal;
}
zClr = rgbName(h,SATURATION,VALUE);
l = x>=0.5;
a1 = a2;
@ <path 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'/>
@ <line stroke='black' stroke-width='1'
@ x1='%g(x3)' y1='%g(y3)' x2='%g(x4)' y2='%g(y4)''/>
if( rot!=0 ){
@ <text text-anchor="%s(zAnc)" transform='rotate(%d(rot),%g(x5),%g(y5))'
}else{
@ <text text-anchor="%s(zAnc)" transform='rotate(%d(rot),%g(x5),%g(y5))'
}
@ x='%g(x5)' y='%g(y5)'>%h(zLbl)</text>
}
db_finalize(&q);
}
/*
** WEBPAGE: test-piechart
**
** Generate a pie-chart based on data input from a form.
*/
void piechart_test_page(void){
const char *zData;
Stmt ins, q;
Blob all, line, token1, token2;
login_check_credentials();
int n = 0;
int width;
int height;
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"));
blob_init(&all, zData, -1);
while( blob_line(&all, &line) ){
double rAmt;
if( blob_token(&line, &token1)==0 ) continue;
rAmt = atof(blob_str(&token1));
if( rAmt<=0.0 ) continue;
blob_tail(&line, &token2);
db_bind_double(&ins, ":amt", rAmt);
db_bind_text(&ins, ":label", blob_str(&token2));
db_step(&ins);
db_reset(&ins);
n++;
}
db_finalize(&ins);
blob_reset(&all);
if( n>0 ){
@ <svg width=%d(width) height=%d(height) style="border:1px solid #d3d3d3;">
piechart_render(width,height, PIE_OTHER|PIE_CHROMATIC);
@ </svg>
@ <hr>
}
@ <form method="post" action='%R/test-piechart'>
@ <p>One slice per line. Value and then Label.<p>
@ <textarea name='data' rows='20' cols='80'>%h(zData)</textarea><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='hidden' name='width' value='%d(width)'/>
@ <input type='hidden' name='height' value='%d(height)'/>
@ <input type='submit' value='Draw The Pie Chart'/>
@ </form>
@ <hr><p>Previous Data:</p>
@ <table border="1">
db_prepare(&q, "SELECT rowid, amt, label FROM piechart");
while( db_step(&q)==SQLITE_ROW ){
@ <tr><td>%d(db_column_int(&q,0))</td>
@ <td>%g(db_column_double(&q,1))</td>
@ <td>%h(db_column_text(&q,2))</td></tr>
}
db_finalize(&q);
@ </table>
style_footer();
}