ChartDirector Ver 3.0 (C++ Edition)

Pattern Area Chart




This example demostrates using a pattern for filling the area in an area chart, together with a number of chart formatting features.

Source Code Listing

[The following project is available in "cppdemo/patternarea".]
#include "chartdir.h" int main(int argc, char *argv[]) { //The data for the area chart double data[] = {3.0, 2.8, 4.0, 5.5, 7.5, 6.8, 5.4, 6.0, 5.0, 6.2, 7.5, 6.5, 7.5, 8.1, 6.0, 5.5, 5.3, 3.5, 5.0, 6.6, 5.6, 4.8, 5.2, 6.5, 6.2}; //The labels for the area chart const char *labels[] = {"0", "", "", "3", "", "", "6", "", "", "9", "", "", "12", "", "", "15", "", "", "18", "", "", "21", "", "", "24"}; //Create a XYChart object of size 300 x 180 pixels. Set the background to //pale yellow (0xffffa0) with a black border (0x0) XYChart *c = new XYChart(300, 180, 0xffffa0, 0x0); //Set the plotarea at (45, 35) and of size 240 x 120 pixels. Set the //background to white (0xffffff). Set both horizontal and vertical grid //lines to black (&H0&) dotted lines (pattern code 0x0103) c->setPlotArea(45, 35, 240, 120, 0xffffff, -1, -1, c->dashLineColor(0x0, 0x103), c->dashLineColor(0x0, 0x103)); //Add a title to the chart using 10 pts Arial Bold font. Use a 1 x 2 bitmap //pattern as the background. Set the border to black (0x0). int pattern[] = {0xb0b0f0, 0xe0e0ff}; c->addTitle("Snow Percipitation (Dec 12)", "arialbd.ttf", 10 )->setBackground(c->patternColor(IntArray(pattern, sizeof(pattern)/sizeof(*pattern)), 2), 0x0); //Add a title to the y axis c->yAxis()->setTitle("mm per hour"); //Set the x axis labels using the given labels c->xAxis()->setLabels(StringArray(labels, sizeof(labels)/sizeof(*labels))); //Add an area layer to the chart AreaLayer *layer = c->addAreaLayer(); //Load a snow pattern from an external file "snow.png". int snowPattern = c->patternColor("snow.png"); //Add a data set to the area layer using the snow pattern as the fill color. //Use deep blue (0x0000ff) as the area border line color (&H0000ff&) layer->addDataSet(DoubleArray(data, sizeof(data)/sizeof(*data)) )->setDataColor(snowPattern, 0xff); //Set the line width to 2 pixels to highlight the line layer->setLineWidth(2); //output the chart c->makeChart("patternarea.png"); //free up resources delete c; return 0; }