[WIP] Pie chart

examples/cpu/CMakeLists.txt

@@ -6,6 +6,7 @@ add_example(bubblechart bubblechart.cpp cpu CXX11)
 add_example(field field.cpp cpu)
 add_example(fractal fractal.cpp cpu)
 add_example(histogram histogram.cpp cpu)
+add_example(pie pie.cpp cpu)
 add_example(plot3 plot3.cpp cpu)
 add_example(plotting plotting.cpp cpu)
 add_example(stream stream.cpp cpu)

examples/cpu/pie.cpp

@@ -0,0 +1,81 @@
+/*******************************************************
+ * Copyright (c) 2015-2019, ArrayFire
+ * All rights reserved.
+ *
+ * This file is distributed under 3-clause BSD license.
+ * The complete license agreement can be obtained at:
+ * http://arrayfire.com/licenses/BSD-3-Clause
+ ********************************************************/
+
+#include <forge.h>
+#define USE_FORGE_CPU_COPY_HELPERS
+#include <ComputeCopy.h>
+#include <cmath>
+#include <cstdlib>
+#include <iostream>
+#include <vector>
+
+const unsigned DIMX     = 1000;
+const unsigned DIMY     = 800;
+const unsigned NSECTORS = 10;
+
+std::vector<float> generateSectors(unsigned count = NSECTORS) {
+    std::vector<float> result;
+    float prefixSum = 0;
+    for (; count > 0; --count) {
+        result.push_back(prefixSum);
+        result.push_back(std::rand() & 0xffff);
+        prefixSum += result.back();
+    }
+    return result;
+}
+
+std::vector<float> generateColors(unsigned count = NSECTORS) {
+    std::vector<float> result;
+    for (; count > 0; --count) {
+        for (int channel = 0; channel < 3; ++channel)
+            result.push_back(std::rand() / (float)RAND_MAX);
+    }
+    return result;
+}
+
+int main(int argc, char* argv[]) {
+    /*
+     * First Forge call should be a window creation call
+     * so that necessary OpenGL context is created for any
+     * other forge::* object to be created successfully
+     */
+    forge::Window wnd(DIMX, DIMY, "Pie Demo");
+    wnd.makeCurrent();
+
+    forge::Chart chart(FG_CHART_2D);
+
+    /*
+     * Create pie object specifying number of bins
+     */
+    forge::Pie pie = chart.pie(NSECTORS, forge::f32);
+
+    GfxHandle* handles[2];
+    createGLBuffer(&handles[0], pie.vertices(), FORGE_VERTEX_BUFFER);
+    createGLBuffer(&handles[1], pie.colors(), FORGE_VERTEX_BUFFER);
+
+    std::vector<float> pieArray = generateSectors();
+    std::vector<float> colArray = generateColors();
+
+    /* set the axes limits to minimum and maximum values of data */
+    float valueRange =
+        pieArray[pieArray.size() - 2] + pieArray[pieArray.size() - 1];
+    chart.setAxesLimits(0, valueRange, 0, valueRange);
+
+    copyToGLBuffer(handles[0], (ComputeResourceHandle)pieArray.data(),
+                   pie.verticesSize());
+    copyToGLBuffer(handles[1], (ComputeResourceHandle)colArray.data(),
+                   pie.colorsSize());
+
+    do { wnd.draw(chart); } while (!wnd.close());
+
+    releaseGLBuffer(handles[0]);
+    releaseGLBuffer(handles[1]);
+
+    return 0;
+}

include/fg/chart.h

@@ -10,12 +10,12 @@
 #pragma once
 
 #include <fg/defines.h>
+#include <fg/histogram.h>
 #include <fg/image.h>
+#include <fg/pie.h>
 #include <fg/plot.h>
 #include <fg/surface.h>
 #include <fg/vector_field.h>
-#include <fg/histogram.h>
-
 
 #ifdef __cplusplus
 extern "C" {
@@ -148,6 +148,16 @@ FGAPI fg_err fg_append_image_to_chart(fg_chart pChart, fg_image pImage);
  */
 FGAPI fg_err fg_append_histogram_to_chart(fg_chart pChart, fg_histogram pHistogram);
 
+/**
+   Add an existing pie object to chart
+
+   \param[in] pChart is the chart to which pie has to be added
+   \param[in] pPie is the pie to be added to the chart
+
+   \return \ref fg_err error code
+ */
+FGAPI fg_err fg_append_pie_to_chart(fg_chart pChart, fg_pie pPie);
+
 /**
    Add an existing plot object to chart
 
@@ -211,6 +221,21 @@ FGAPI fg_err fg_add_image_to_chart(fg_image* pImage, fg_chart pHandle,
 FGAPI fg_err fg_add_histogram_to_chart(fg_histogram* pHistogram, fg_chart pHandle,
                                        const unsigned pNBins, const fg_dtype pType);
 
+/**
+   Create and add a Pie object to the current chart
+
+   \param[out] pPie is the handle of the pie object created
+   \param[in] pHandle is chart handle
+   \param[in] pNSectors is number of sectors the data is sorted out
+   \param[in] pType takes one of the values of \ref fg_dtype that indicates
+              the integral data type of pie data
+
+   \return \ref fg_err error code
+ */
+FGAPI fg_err fg_add_pie_to_chart(fg_pie *pPie, fg_chart pHandle,
+                                 const unsigned pNSectors,
+                                 const fg_dtype pType);
+
 /**
    Create and add an Plot object to the current chart
 
@@ -283,6 +308,16 @@ Remove a Histogram object from the current chart
 FGAPI fg_err fg_remove_histogram_from_chart(fg_chart pHandle,
                                             fg_histogram pHistogram);
 
+/**
+Remove a Pie object from the current chart
+
+\param[in] pHandle is chart handle
+\param[in] pPie is the handle of the pie object to remove
+
+\return \ref fg_err error code
+*/
+FGAPI fg_err fg_remove_pie_from_chart(fg_chart pHandle, fg_pie pPie);
+
 /**
 Remove a Plot object from the current chart
 
@@ -459,6 +494,13 @@ class Chart {
          */
         FGAPI void add(const Histogram& pHistogram);
 
+        /**
+           Add an existing Pie object to the current chart
+
+           \param[in] pPie is the Pie to render on the chart
+         */
+        FGAPI void add(const Pie &pPie);
+
         /**
            Add an existing Plot object to the current chart
 
@@ -494,6 +536,13 @@ class Chart {
         */
         FGAPI void remove(const Histogram &pHistogram);
 
+        /**
+        Remove an existing Pie object to the current chart
+
+        \param[in] pPie is the Pie to remove from the chart
+        */
+        FGAPI void remove(const Pie &pPie);
+
         /**
         Remove an existing Plot object to the current chart
 
@@ -537,6 +586,15 @@ class Chart {
          */
         FGAPI Histogram histogram(const unsigned pNBins, const dtype pDataType);
 
+        /**
+           Create and add a Pie object to the current chart
+
+           \param[in] pNSectors is number of sectors the data is sorted out
+           \param[in] pDataType takes one of the values of \ref dtype that
+           indicates the integral data type of pie data
+         */
+        FGAPI Pie pie(const unsigned pNSectors, const dtype pDataType);
+
         /**
            Create and add an Plot object to the current chart
 

include/fg/defines.h

@@ -49,6 +49,9 @@ typedef void* fg_image;
 /// \brief Histogram handle
 typedef void* fg_histogram;
 
+/// \brief Pie handle
+typedef void *fg_pie;
+
 /// \brief Plot handle
 typedef void* fg_plot;
 

include/fg/histogram.h

@@ -58,8 +58,8 @@ FGAPI fg_err fg_release_histogram(fg_histogram pHistogram);
    This is global alpha value for the histogram rendering that takes
    effect if individual bar alphas are not set by calling the following
    member functions
-       - Histogram::alphas()
-       - Histogram::alphasSize()
+       - fg_get_histogram_alpha_buffer
+       - fg_get_histogram_alpha_buffer_size
 
    \param[in] pHistogram is the histogram handle
    \param[in] pRed is Red component in range [0, 1]