[enhancement] New Graphics implementation with algorithm for spirograph (#557)

* skeleton of spirograph

* add graphics to cmake

* updating DIRECTORY.md

* added cmake to graphics folder

* add stub test function

* working program

* set pre-processor macro if GLUT is available

* use snprintf

details: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1967.htm

* conditional include for mac

* corrected conditional include for mac

* fix cmake for MACOS

* OpenGL animation if available, else plot to CSV

* MacOS does not provide glutBitmapString function

* formatting source-code for 8d570b4c28

* fix parameter

* try caps include path GL

* provide custom glutBitmapString cuntion

* add glut library to gitpod docker

* enable VNC in gitpod

* better documentation and cmake configuration

* enable keyboard inputs to pause and change parameters

* fix lgtm alerts

* implementation similar to one in C++ repo

* fix compilation errors on MSVC

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
This commit is contained in:
Krishna Vedala 2020-07-10 15:48:07 -04:00 committed by GitHub
parent cdf8453db8
commit 9a9781064f
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5 changed files with 423 additions and 34 deletions

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@ -1,9 +1,11 @@
FROM gitpod/workspace-full FROM gitpod/workspace-full-vnc
RUN sudo apt-get update \ RUN sudo apt-get update \
&& sudo apt-get install -y \ && sudo apt-get install -y \
doxygen \ doxygen \
graphviz \ graphviz \
ninja-build \ ninja-build \
freeglut3 \
freeglut3-dev \
&& pip install cpplint \ && pip install cpplint \
&& sudo rm -rf /var/lib/apt/lists/* && sudo rm -rf /var/lib/apt/lists/*

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@ -1,11 +1,38 @@
cmake_minimum_required(VERSION 3.3) cmake_minimum_required(VERSION 3.6)
project(Algorithms_in_C project(Algorithms_in_C
LANGUAGES C LANGUAGES C
VERSION 1.0.0 VERSION 1.0.0
DESCRIPTION "Set of algorithms implemented in C." DESCRIPTION "Set of algorithms implemented in C."
) )
set(CMAKE_C_STANDARD 11)
set(CMAKE_C_STANDARD_REQUIRED YES)
if(MSVC)
add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
# add_compile_options(/Za)
endif(MSVC)
find_library(MATH_LIBRARY m)
option(USE_OPENMP "flag to use OpenMP for multithreading" ON) option(USE_OPENMP "flag to use OpenMP for multithreading" ON)
if(USE_OPENMP)
find_package(OpenMP)
if (OpenMP_C_FOUND)
message(STATUS "Building with OpenMP Multithreading.")
else()
message(STATUS "No OpenMP found, no multithreading.")
endif()
endif()
add_subdirectory(misc)
add_subdirectory(sorting)
add_subdirectory(graphics)
add_subdirectory(searching)
add_subdirectory(conversions)
add_subdirectory(project_euler)
add_subdirectory(machine_learning)
add_subdirectory(numerical_methods)
cmake_policy(SET CMP0054 NEW) cmake_policy(SET CMP0054 NEW)
cmake_policy(SET CMP0057 NEW) cmake_policy(SET CMP0057 NEW)
@ -21,6 +48,7 @@ if(DOXYGEN_FOUND)
set(DOXYGEN_GENERATE_TREEVIEW YES) set(DOXYGEN_GENERATE_TREEVIEW YES)
set(DOXYGEN_JAVADOC_AUTOBRIEF YES) set(DOXYGEN_JAVADOC_AUTOBRIEF YES)
set(DOXYGEN_STRIP_CODE_COMMENTS NO) set(DOXYGEN_STRIP_CODE_COMMENTS NO)
set(DOXYGEN_ENABLE_PREPROCESSING YES)
set(DOXYGEN_EXT_LINKS_IN_WINDOW YES) set(DOXYGEN_EXT_LINKS_IN_WINDOW YES)
set(DOXYGEN_OPTIMIZE_OUTPUT_FOR_C YES) set(DOXYGEN_OPTIMIZE_OUTPUT_FOR_C YES)
set(DOXYGEN_CLANG_ASSISTED_PARSING YES) set(DOXYGEN_CLANG_ASSISTED_PARSING YES)
@ -34,6 +62,12 @@ if(DOXYGEN_FOUND)
set(DOXYGEN_INTERACTIVE_SVG YES) set(DOXYGEN_INTERACTIVE_SVG YES)
set(DOXYGEN_DOT_IMAGE_FORMAT "svg") set(DOXYGEN_DOT_IMAGE_FORMAT "svg")
endif() endif()
if(OPENMP_FOUND)
set(DOXYGEN_PREDEFINED "_OPENMP=1")
endif()
if(GLUT_FOUND)
set(DOXYGEN_PREDEFINED ${DOXYGEN_PREDEFINED} "GLUT_FOUND=1")
endif()
doxygen_add_docs( doxygen_add_docs(
doc doc
@ -42,32 +76,6 @@ if(DOXYGEN_FOUND)
) )
endif() endif()
set(CMAKE_C_STANDARD 11)
set(CMAKE_C_STANDARD_REQUIRED YES)
if(MSVC)
add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
# add_compile_options(/Za)
endif(MSVC)
find_library(MATH_LIBRARY m)
if(USE_OPENMP)
find_package(OpenMP)
if (OpenMP_C_FOUND)
message(STATUS "Building with OpenMP Multithreading.")
else()
message(STATUS "No OpenMP found, no multithreading.")
endif()
endif()
add_subdirectory(misc)
add_subdirectory(sorting)
add_subdirectory(searching)
add_subdirectory(conversions)
add_subdirectory(project_euler)
add_subdirectory(machine_learning)
add_subdirectory(numerical_methods)
set(CPACK_PROJECT_NAME ${PROJECT_NAME}) set(CPACK_PROJECT_NAME ${PROJECT_NAME})
set(CPACK_PROJECT_VERSION ${PROJECT_VERSION}) set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})

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@ -107,6 +107,9 @@
* [Word Count](https://github.com/TheAlgorithms/C/blob/master/exercism/word_count/word_count.c) * [Word Count](https://github.com/TheAlgorithms/C/blob/master/exercism/word_count/word_count.c)
* [Word Count](https://github.com/TheAlgorithms/C/blob/master/exercism/word_count/word_count.h) * [Word Count](https://github.com/TheAlgorithms/C/blob/master/exercism/word_count/word_count.h)
## Graphics
* [Spirograph](https://github.com/TheAlgorithms/C/blob/master/graphics/spirograph.c)
## Greedy Approach ## Greedy Approach
* [Djikstra](https://github.com/TheAlgorithms/C/blob/master/greedy_approach/djikstra.c) * [Djikstra](https://github.com/TheAlgorithms/C/blob/master/greedy_approach/djikstra.c)

88
graphics/CMakeLists.txt Normal file
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@ -0,0 +1,88 @@
find_package(OpenGL)
if(OpenGL_FOUND)
find_package(GLUT)
if(NOT GLUT_FOUND)
message("FreeGLUT library will be downloaded and built.")
include(ExternalProject)
ExternalProject_Add (
FREEGLUT-PRJ
URL https://sourceforge.net/projects/freeglut/files/freeglut/3.2.1/freeglut-3.2.1.tar.gz
URL_MD5 cd5c670c1086358598a6d4a9d166949d
CMAKE_GENERATOR ${CMAKE_GENERATOR} --config Release
CMAKE_GENERATOR_TOOLSET ${CMAKE_GENERATOR_TOOLSET}
CMAKE_GENERATOR_PLATFORM ${CMAKE_GENERATOR_PLATFORM}
CMAKE_ARGS -DCMAKE_BUILD_TYPE=Release
-DFREEGLUT_BUILD_SHARED_LIBS=OFF
-DFREEGLUT_BUILD_STATIC_LIBS=ON
-DFREEGLUT_BUILD_DEMOS=OFF
PREFIX ${CMAKE_CURRENT_BINARY_DIR}/freeglut
# BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/freeglut-build
# BUILD_IN_SOURCE ON
# UPDATE_COMMAND ""
INSTALL_COMMAND ""
# CONFIGURE_COMMAND ""
# BUILD_COMMAND ""
)
ExternalProject_Get_Property(FREEGLUT-PRJ SOURCE_DIR)
ExternalProject_Get_Property(FREEGLUT-PRJ BINARY_DIR)
set(FREEGLUT_BIN_DIR ${BINARY_DIR})
set(FREEGLUT_SRC_DIR ${SOURCE_DIR})
# add_library(libfreeglut STATIC IMPORTED)
# set_target_properties(libfreeglut PROPERTIES IMPORTED_LOCATION ${FREEGLUT_BIN_DIR})
# set(FREEGLUT_BUILD_DEMOS OFF CACHE BOOL "")
# set(FREEGLUT_BUILD_SHARED_LIBS OFF CACHE BOOL "")
# set(FREEGLUT_BUILD_STATIC_LIBS ON CACHE BOOL "")
# add_subdirectory(${FREEGLUT_SRC_DIR} ${FREEGLUT_BIN_DIR} EXCLUDE_FROM_ALL)
# add_subdirectory(${BINARY_DIR})
# find_package(FreeGLUT)
endif(NOT GLUT_FOUND)
else(OpenGL_FOUND)
message(WARNING "OPENGL not found. Will not build graphical outputs.")
endif(OpenGL_FOUND)
# If necessary, use the RELATIVE flag, otherwise each source file may be listed
# with full pathname. RELATIVE may makes it easier to extract an executable name
# automatically.
file( GLOB APP_SOURCES RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} *.c )
# file( GLOB APP_SOURCES ${CMAKE_SOURCE_DIR}/*.c )
# AUX_SOURCE_DIRECTORY(${CMAKE_CURRENT_SOURCE_DIR} APP_SOURCES)
foreach( testsourcefile ${APP_SOURCES} )
# I used a simple string replace, to cut off .cpp.
string( REPLACE ".c" "" testname ${testsourcefile} )
add_executable( ${testname} ${testsourcefile} )
# set_target_properties(${testname} PROPERTIES LINKER_LANGUAGE C)
if(OpenMP_C_FOUND)
target_link_libraries(${testname} PRIVATE OpenMP::OpenMP_C)
endif()
if(MATH_LIBRARY)
target_link_libraries(${testname} PRIVATE ${MATH_LIBRARY})
endif()
if(OpenGL_FOUND)
if(NOT GLUT_FOUND)
add_dependencies(${testname} FREEGLUT-PRJ)
target_compile_definitions(${testname} PRIVATE FREEGLUT_STATIC)
target_include_directories(${testname} PRIVATE ${FREEGLUT_SRC_DIR}/include)
target_link_directories(${testname} PRIVATE ${FREEGLUT_BIN_DIR}/lib)
target_link_libraries(${testname} PRIVATE OpenGL::GL)
target_link_libraries(${testname} INTERFACE FREEGLUT-PRJ)
# target_include_directories(${testname} PRIVATE ${FREEGLUT_INCLUDE_DIRS})
# target_link_libraries(${testname} INTERFACE freeglut_static)
else()
target_include_directories(${testname} PRIVATE ${GLUT_INCLUDE_DIRS})
target_link_libraries(${testname} PRIVATE OpenGL::GL ${GLUT_LIBRARIES})
endif()
target_compile_definitions(${testname} PRIVATE USE_GLUT)
endif(OpenGL_FOUND)
if(APPLE)
target_compile_options(${testname} PRIVATE -Wno-deprecated)
endif(APPLE)
install(TARGETS ${testname} DESTINATION "bin/graphics")
endforeach( testsourcefile ${APP_SOURCES} )

288
graphics/spirograph.c Normal file
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@ -0,0 +1,288 @@
/**
* @file
* @author [Krishna Vedala](https://github.com/kvedala)
* @brief Implementation of
* [Spirograph](https://en.wikipedia.org/wiki/Spirograph)
*
* @details
* Implementation of the program is based on the geometry shown in the figure
* below:
*
* <a
* href="https://commons.wikimedia.org/wiki/File:Resonance_Cascade.svg"><img
* src="https://upload.wikimedia.org/wikipedia/commons/3/39/Resonance_Cascade.svg"
* alt="Spirograph geometry from Wikipedia" style="width: 250px"/></a>
*/
#define _USE_MATH_DEFINES /**< required for MSVC compiler */
#include <math.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
/** Generate spirograph curve into arrays `x` and `y` such that the i^th point
* in 2D is represented by `(x[i],y[i])`. The generating function is given by:
* \f{eqnarray*}{
* x &=& R\left[ (1-k) \cos (t) + l\cdot k\cdot\cos \left(\frac{1-k}{k}t\right)
* \right]\\
* y &=& R\left[ (1-k) \sin (t) - l\cdot k\cdot\sin \left(\frac{1-k}{k}t\right)
* \right] \f}
* where
* * \f$R\f$ is the scaling parameter that we will consider \f$=1\f$
* * \f$l=\frac{\rho}{r}\f$ is the relative distance of marker from the centre
* of inner circle and \f$0\le l\le1\f$
* * \f$\rho\f$ is physical distance of marker from centre of inner circle
* * \f$r\f$ is the radius of inner circle
* * \f$k=\frac{r}{R}\f$ is the ratio of radius of inner circle to outer circle
* and \f$0<k<1\f$
* * \f$R\f$ is the radius of outer circle
* * \f$t\f$ is the angle of rotation of the point i.e., represents the time
* parameter
*
* Since we are considering ratios, the actual values of \f$r\f$ and
* \f$R\f$ are immaterial.
*
* @param [out] x output array containing absicca of points (must be
* pre-allocated)
* @param [out] y output array containing ordinates of points (must be
* pre-allocated)
* @param l the relative distance of marker from the centre of
* inner circle and \f$0\le l\le1\f$
* @param k the ratio of radius of inner circle to outer circle and
* \f$0<k<1\f$
* @param N number of sample points along the trajectory (higher = better
* resolution but consumes more time and memory)
* @param num_rot the number of rotations to perform (can be fractional value)
*/
void spirograph(double *x, double *y, double l, double k, size_t N, double rot)
{
double dt = rot * 2.f * M_PI / N;
double t = 0.f, R = 1.f;
const double k1 = 1.f - k;
for (size_t dk = 0; dk < N; dk++, t += dt)
{
x[dk] = R * (k1 * cos(t) + l * k * cos(k1 * t / k));
y[dk] = R * (k1 * sin(t) - l * k * sin(k1 * t / k));
}
}
/**
* @brief Test function to save resulting points to a CSV file.
*
*/
void test(void)
{
size_t N = 500;
double l = 0.3, k = 0.75, rot = 10.;
char fname[50];
snprintf(fname, 50, "spirograph_%.2f_%.2f_%.2f.csv", l, k, rot);
FILE *fp = fopen(fname, "wt");
if (!fp)
{
perror(fname);
exit(EXIT_FAILURE);
}
double *x = (double *)malloc(N * sizeof(double));
double *y = (double *)malloc(N * sizeof(double));
spirograph(x, y, l, k, N, rot);
for (size_t i = 0; i < N; i++)
{
fprintf(fp, "%.5g, %.5g", x[i], y[i]);
if (i < N - 1)
{
fputc('\n', fp);
}
}
fclose(fp);
free(x);
free(y);
}
#ifdef USE_GLUT // this is set by CMAKE automatically, if available
#ifdef __APPLE__
#include <GLUT/glut.h> // include path on Macs is different
#else
#include <GL/glut.h>
#endif
static bool paused = 0; /**< flag to set pause/unpause animation */
static const int animation_speed = 25; /**< animation delate in ms */
static const double step = 0.01; /**< animation step size */
static double l_ratio = 0.1; /**< the l-ratio defined in docs */
static double k_ratio = 0.1; /**< the k-ratio defined in docs */
static const double num_rot = 20.; /**< number of rotations to simulate */
/** A wrapper that is not available in all GLUT implementations.
*/
static inline void glutBitmapString(void *font, char *string)
{
for (char *ch = string; *ch != '\0'; ch++) glutBitmapCharacter(font, *ch);
}
/**
* @brief Function to graph (x,y) points on the OpenGL graphics window.
*
* @param x array containing absicca of points (must be pre-allocated)
* @param y array containing ordinates of points (must be pre-allocated)
* @param N number of points in the the arrays
*/
void display_graph(const double *x, const double *y, size_t N, double l,
double k)
{
glClearColor(1.0f, 1.0f, 1.0f,
0.0f); // Set background color to white and opaque
glClear(GL_COLOR_BUFFER_BIT); // Clear the color buffer (background)
if (x && y)
{
glBegin(GL_LINES); // draw line segments
glColor3f(0.f, 0.f, 1.f); // blue
glPointSize(2.f); // point size in pixels
for (size_t i = 1; i < N; i++)
{
glVertex2f(x[i - 1], y[i - 1]); // line from
glVertex2f(x[i], y[i]); // line to
}
glEnd();
}
glColor3f(0.f, 0.f, 0.f);
char buffer[20];
snprintf(buffer, 20, "l = %.3f", l);
glRasterPos2f(-.85, .85);
glutBitmapString(GLUT_BITMAP_HELVETICA_18, buffer);
snprintf(buffer, 20, "k = %.3f", k);
glRasterPos2f(-.85, .75);
glutBitmapString(GLUT_BITMAP_HELVETICA_18, buffer);
glutSwapBuffers();
}
/**
* @brief Test function with animation
*
*/
void test2(void)
{
const size_t N = 1000; // number of samples
static bool direction1 = true; // increment if true, otherwise decrement
static bool direction2 = true; // increment if true, otherwise decrement
double *x = (double *)malloc(N * sizeof(double));
double *y = (double *)malloc(N * sizeof(double));
spirograph(x, y, l_ratio, k_ratio, N, num_rot);
display_graph(x, y, N, l_ratio, k_ratio);
free(x); // free dynamic memories
free(y);
if (paused)
// if paused, do not update l_ratio and k_ratio
return;
if (direction1) // increment k_ratio
{
if (k_ratio >= (1.f - step)) // maximum limit
direction1 = false; // reverse direction of k_ratio
else
k_ratio += step;
}
else // decrement k_ratio
{
if (k_ratio <= step) // minimum limit
{
direction1 = true; // reverse direction of k_ratio
if (direction2) // increment l_ratio
{
if (l_ratio >= (1.f - step)) // max limit of l_ratio
direction2 = false; // reverse direction of l_ratio
else
l_ratio += step;
}
else // decrement l_ratio
{
if (l_ratio <= step) // minimum limit of l_ratio
direction2 = true; // reverse direction of l_ratio
else
l_ratio -= step;
}
}
else // no min limit of k_ratio
k_ratio -= step;
}
}
/**
* @brief GLUT timer callback function to add animation delay.
*/
void timer_cb(int id)
{
glutPostRedisplay();
glutTimerFunc(animation_speed, timer_cb, 0);
}
/**
* @brief Keypress event call back function.
*
* @param key ID of the key pressed
* @param x mouse pointer position at event
* @param y mouse pointer position at event
*/
void keyboard_cb(unsigned char key, int x, int y)
{
switch (key)
{
case ' ': // spacebar toggles pause
paused = !paused; // toggle
break;
case '+': // up arrow key
k_ratio += step;
display_graph(NULL, NULL, 1, l_ratio, k_ratio);
break;
case '_': // down arrow key
k_ratio -= step;
display_graph(NULL, NULL, 1, l_ratio, k_ratio);
break;
case '=': // left arrow key
l_ratio += step;
display_graph(NULL, NULL, 1, l_ratio, k_ratio);
break;
case '-': // right arrow key
l_ratio -= step;
display_graph(NULL, NULL, 1, l_ratio, k_ratio);
break;
case 0x1B: // escape key exits
exit(EXIT_SUCCESS);
}
}
#endif
/** Main function */
int main(int argc, char **argv)
{
test();
#ifdef USE_GLUT
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
glutCreateWindow("Spirograph");
glutInitWindowSize(400, 400);
// glutIdleFunc(glutPostRedisplay);
glutTimerFunc(animation_speed, timer_cb, 0);
glutKeyboardFunc(keyboard_cb);
glutDisplayFunc(test2);
glutMainLoop();
#endif
return 0;
}