Graph

Output of the graph demo. Click to see without artifacts.

The graph window allows to easily draw curves and other sets of data with different colors and shapes in a rectangular window. The graph doesn't take any user input.

API reference

The API reference of the graph window can be found here.

Style

The graph window provides an interface to modify the appearance of the graph itself and the data it displays. This contains the following properties:

• Point
  • Type (None / Dot / Square / Circle)
  • Radius
  • Color
• Lines
  • Type (None / Solid / Dot / Dash)
  • Thickness
  • Color
• X-Axis line
  • Type (Solid / Dot / Dash)
  • Thickness
  • Color
• Y-Axis
  • Type (Solid / Dot / Dash)
  • Thickness
  • Color
• X-Axis grid
  • Type (Solid / Dot / Dash)
  • Thickness
  • Color
  • Spacing
• Y-Axis grid
  • Type (Solid / Dot / Dash)
  • Thickness
  • Color
  • Spacing
• Flags
  • Arrows

Example

The following example draws three curves with different colors and shapes within the same graph widget. Make sure you got the math library included into your build path (-lm).

#include "gfx.h"
#include "math.h"
 
// A set of data points that will be displayed in the graph
static const point data[5] = {
    { -40, -40 },
    { 70, 40 },
    { 140, 60 },
    { 210, 60 },
    { 280, 200 }
};
 
// The graph object
static GGraphObject g;
 
// A graph styling
static GGraphStyle GraphStyle1 = {
    { GGRAPH_POINT_DOT, 0, Blue },          // Point
    { GGRAPH_LINE_NONE, 2, Gray },          // Line
    { GGRAPH_LINE_SOLID, 0, White },        // X axis
    { GGRAPH_LINE_SOLID, 0, White },        // Y axis
    { GGRAPH_LINE_DASH, 5, Gray, 50 },      // X grid
    { GGRAPH_LINE_DOT, 7, Yellow, 50 },     // Y grid
    GWIN_GRAPH_STYLE_POSITIVE_AXIS_ARROWS   // Flags
};
 
// Another graph styling 
static const GGraphStyle GraphStyle2 = {
    { GGRAPH_POINT_SQUARE, 5, Red },        // Point
    { GGRAPH_LINE_DOT, 2, Pink },           // Line
    { GGRAPH_LINE_SOLID, 0, White },        // X axis
    { GGRAPH_LINE_SOLID, 0, White },        // Y axis
    { GGRAPH_LINE_DASH, 5, Gray, 50 },      // X grid
    { GGRAPH_LINE_DOT, 7, Yellow, 50 },     // Y grid
    GWIN_GRAPH_STYLE_POSITIVE_AXIS_ARROWS   // Flags
};
 
int main(void) {
    GHandle     gh;
    uint16_t    i;
 
    gfxInit();
 
    // Create the graph window
    {
        GWindowInit wi;
 
        wi.show = TRUE;
        wi.x = wi.y = 0;
        wi.width = gdispGetWidth();
        wi.height = gdispGetHeight();
        gh = gwinGraphCreate(&g, &wi);
    }
 
    // Set the graph origin and style
    gwinGraphSetOrigin(gh, gwinGetWidth(gh)/2, gwinGetHeight(gh)/2);
    gwinGraphSetStyle(gh, &GraphStyle1);
    gwinGraphDrawAxis(gh);
 
    // Draw a sine wave
    for(i = 0; i < gwinGetWidth(gh); i++) {
        gwinGraphDrawPoint(gh, i-gwinGetWidth(gh)/2, 80*sin(2*0.2*M_PI*i/180));
    }
 
    // Modify the style
    gwinGraphStartSet(gh);
    GraphStyle1.point.color = Green;
    gwinGraphSetStyle(gh, &GraphStyle1);
 
    // Draw a different sine wave
    for(i = 0; i < gwinGetWidth(gh)*5; i++) {
        gwinGraphDrawPoint(gh, i/5-gwinGetWidth(gh)/2, 95*sin(2*0.2*M_PI*i/180));
    }
 
    // Change to a completely different style
    gwinGraphStartSet(gh);
    gwinGraphSetStyle(gh, &GraphStyle2);
 
    // Draw a set of points
    gwinGraphDrawPoints(gh, data, sizeof(data)/sizeof(data[0]));
 
    while(TRUE) {
        gfxSleepMilliseconds(100);
    }
}