Reorganize cpp/opengl-cmake

+ So project structure is closer to that of cpp/sdl-cmake

cpp/opengl-cmake/CMakeLists.txt

@@ -15,15 +15,15 @@ project(
     LANGUAGES    CXX
 )
 
-# Add test executable
-add_executable(opengl-test "test-gl.cpp")
+add_library(lib-opengl-test "src/lib-opengl-test.cpp")
+target_include_directories(lib-opengl-test PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/src)
 
 # Find OpenGL package
 find_package(OpenGL REQUIRED)
 if (OPENGL_FOUND)
   # Link opengl-test executable to OpenGL
-  target_include_directories(opengl-test PUBLIC ${OPENGL_INCLUDE_DIR})
-  target_link_libraries(opengl-test PUBLIC ${OPENGL_LIBRARIES})
+  target_include_directories(lib-opengl-test PUBLIC ${OPENGL_INCLUDE_DIR})
+  target_link_libraries(lib-opengl-test PUBLIC ${OPENGL_LIBRARIES})
 
 else()
   message(
@@ -35,13 +35,18 @@ endif()
 # Find GLUT package
 find_package(GLUT REQUIRED)
 if (GLUT_FOUND)
-  # Link opengl-test executable to GLUT
-  target_include_directories(opengl-test PUBLIC ${GLUT_INCLUDE_DIR})
-  target_link_libraries(opengl-test PUBLIC ${GLUT_LIBRARIES})
+  # Link lib-opengl-test executable to GLUT
+  target_include_directories(lib-opengl-test PUBLIC ${GLUT_INCLUDE_DIR})
+  target_link_libraries(lib-opengl-test PUBLIC ${GLUT_LIBRARIES})
 
 else()
   message(
-      "Error: CMake was unable to find the OpenGL package\n"
-      "Please install OpenGL and try again\n"
+      "Error: CMake was unable to find the GLUT package\n"
+      "Please install GLUT (freeglut3-dev) and try again\n"
   )
 endif()
+
+# Add test executable
+add_executable(opengl-test "apps/test-gl.cpp")
+target_link_libraries(opengl-test PRIVATE lib-opengl-test)
+target_include_directories(opengl-test PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/src)

cpp/opengl-cmake/apps/test-gl.cpp

@@ -0,0 +1,60 @@
+/*#############################################################################
+## Requires freeglut3-dev to be installed with your package manager          ##
+## To build an executable: `g++ test-gl.cpp -w -lGL -lGLU -lglut -o test`    ##
+##                                                                           ##
+## Testing building OpenGL projects with source code from lazyfoo -          ##
+## https://lazyfoo.net/tutorials/OpenGL/                                     ##
+##############################################################################
+## test-gl.cpp
+*/
+
+#include <lib-opengl-test.hpp>
+
+#include <GL/freeglut.h>
+
+#include <cstdio>
+
+//Screen constants
+const int SCREEN_WIDTH = 640;
+const int SCREEN_HEIGHT = 480;
+const int SCREEN_FPS = 60;
+
+//Color modes
+const int COLOR_MODE_CYAN = 0;
+const int COLOR_MODE_MULTI = 1;
+
+int main( int argc, char* args[] )
+{
+  //Initialize FreeGLUT
+  glutInit( &argc, args );
+
+  //Create OpenGL 2.1 context
+  glutInitContextVersion( 2, 1 );
+
+  //Create Double Buffered Window
+  glutInitDisplayMode( GLUT_DOUBLE );
+  glutInitWindowSize( SCREEN_WIDTH, SCREEN_HEIGHT );
+  glutCreateWindow( "OpenGL" );
+
+  //Do post window/context creation initialization
+  if( !initGL() )
+  {
+    printf( "Unable to initialize graphics library!\n" );
+    return 1;
+  }
+
+  //Set keyboard handler
+  glutKeyboardFunc( handleKeys );
+
+  //Set rendering function
+  glutDisplayFunc( render );
+
+  //Set main loop
+  glutTimerFunc( 1000 / SCREEN_FPS, runMainLoop, 0 );
+
+  //Start GLUT main loop
+  glutMainLoop();
+
+  return 0;
+}
+

cpp/opengl-cmake/src/lib-opengl-test.cpp

@@ -1,18 +1,11 @@
-/*#############################################################################
-## Author: Shaun Reed                                                        ##
-## Requires freeglut3-dev to be installed with your package manager          ##
-## To build an executable: `g++ test-gl.cpp -w -lGL -lGLU -lglut -o test`    ##
-##                                                                           ##
-## Testing building OpenGL projects with source code from lazyfoo -          ##
-## https://lazyfoo.net/tutorials/OpenGL/                                     ##
-##############################################################################
-## test-gl.cpp
-*/
+
+#include <lib-opengl-test.hpp>
 
 #include <GL/freeglut.h>
 #include <GL/gl.h>
 #include <GL/glu.h>
-#include <stdio.h>
+
+#include <cstdio>
 
 //Screen constants
 const int SCREEN_WIDTH = 640;
@@ -24,11 +17,21 @@ const int COLOR_MODE_CYAN = 0;
 const int COLOR_MODE_MULTI = 1;
 
 //The current color rendering mode
-int gColorMode = COLOR_MODE_CYAN;
+int gColorMode = 0;
 
 //The projection scale
 GLfloat gProjectionScale = 1.f;
 
+void runMainLoop( int val )
+{
+  //Frame logic
+  update();
+  render();
+
+  //Run frame one more time
+  glutTimerFunc( 1000 / SCREEN_FPS, runMainLoop, val );
+}
+
 bool initGL()
 {
   //Initialize Projection Matrix
@@ -139,57 +142,3 @@ void handleKeys( unsigned char key, int x, int y )
   }
 }
 
-void runMainLoop( int val );
-/*
-Pre Condition:
- -Initialized freeGLUT
-Post Condition:
- -Calls the main loop functions and sets itself to be called back in 1000 / SCREEN_FPS milliseconds
-Side Effects:
- -Sets glutTimerFunc
-*/
-
-int main( int argc, char* args[] )
-{
-  //Initialize FreeGLUT
-  glutInit( &argc, args );
-
-  //Create OpenGL 2.1 context
-  glutInitContextVersion( 2, 1 );
-
-  //Create Double Buffered Window
-  glutInitDisplayMode( GLUT_DOUBLE );
-  glutInitWindowSize( SCREEN_WIDTH, SCREEN_HEIGHT );
-  glutCreateWindow( "OpenGL" );
-
-  //Do post window/context creation initialization
-  if( !initGL() )
-  {
-    printf( "Unable to initialize graphics library!\n" );
-    return 1;
-  }
-
-  //Set keyboard handler
-  glutKeyboardFunc( handleKeys );
-
-  //Set rendering function
-  glutDisplayFunc( render );
-
-  //Set main loop
-  glutTimerFunc( 1000 / SCREEN_FPS, runMainLoop, 0 );
-
-  //Start GLUT main loop
-  glutMainLoop();
-
-  return 0;
-}
-
-void runMainLoop( int val )
-{
-  //Frame logic
-  update();
-  render();
-
-  //Run frame one more time
-  glutTimerFunc( 1000 / SCREEN_FPS, runMainLoop, val );
-}

cpp/opengl-cmake/src/lib-opengl-test.hpp

@@ -0,0 +1,25 @@
+
+#ifndef LIB_OPENGL_TEST_HPP
+#define LIB_OPENGL_TEST_HPP
+
+#include <GL/freeglut.h>
+#include <GL/gl.h>
+#include <GL/glu.h>
+
+void runMainLoop( int val );
+/*
+Pre Condition:
+ -Initialized freeGLUT
+Post Condition:
+ -Calls the main loop functions and sets itself to be called back in 1000 / SCREEN_FPS milliseconds
+Side Effects:
+ -Sets glutTimerFunc
+*/
+
+bool initGL();
+void update();
+void render();
+
+void handleKeys( unsigned char key, int x, int y );
+
+#endif // LIB_OPENGL_TEST_HPP