[Code] Neuen Beispielcode ergänzt

Code/CMakeLists.txt

@@ -7,4 +7,14 @@ endif()
 find_package(OpenGL REQUIRED)
 find_package(GLUT REQUIRED)
 
-add_subdirectory(hello_world)
+add_executable (hello_world hello_world/helloWorld.c)
+target_include_directories(hello_world PRIVATE ${OPENGL_INCLUDE_DIRS}  ${GLUT_INCLUDE_DIRS})
+target_link_libraries(hello_world ${OPENGL_LIBRARIES} ${GLUT_LIBRARY})
+
+add_executable (culling box/template_culling.c)
+target_include_directories(culling PRIVATE ${OPENGL_INCLUDE_DIRS}  ${GLUT_INCLUDE_DIRS})
+target_link_libraries(culling ${OPENGL_LIBRARIES} ${GLUT_LIBRARY})
+
+add_executable (koordinatensystem box/template_koordinatensystemUndPunkte.c)
+target_include_directories(koordinatensystem PRIVATE ${OPENGL_INCLUDE_DIRS}  ${GLUT_INCLUDE_DIRS})
+target_link_libraries(koordinatensystem ${OPENGL_LIBRARIES} ${GLUT_LIBRARY})

Code/box/template_culling.c

@@ -0,0 +1,84 @@
+#include <GL/glut.h>
+#include <string.h>
+
+int width = 800;
+int height = 600;
+
+void init(int argc, char** argv) {
+	glutInit(&argc, argv);					
+	glutInitDisplayMode(GLUT_SINGLE);		
+	glutInitWindowSize(width, height);		
+	glutInitWindowPosition(100, 100);		
+	glViewport(0,0,width,height);
+	glutCreateWindow("Culling");		
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	glMatrixMode(GL_MODELVIEW);
+	glOrtho(-2.0, 2.0,-2.0, 2.0, -2.0, 2.0);
+	gluLookAt(0.25,0.5,0.1,0,0,0,0,1,0);
+
+
+	////////////////////////////////////////////////////////////////////
+
+    glEnable(GL_CULL_FACE);
+    glCullFace(GL_FRONT);
+
+	////////////////////////////////////////////////////////////////////
+}
+
+
+void display(void)
+{
+
+	glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glEnable(GL_DEPTH_TEST);
+	glDepthFunc(GL_LEQUAL);
+
+	glBegin(GL_QUADS);
+
+		glColor3f(1.0f, 0.0f, 0.0f);
+		// FRONT
+		glVertex3f(-0.5f, -0.5f,  0.5f);
+		glVertex3f( 0.5f, -0.5f,  0.5f);
+		glVertex3f( 0.5f,  0.5f,  0.5f);
+		glVertex3f(-0.5f,  0.5f,  0.5f);
+		// BACK
+		glVertex3f(-0.5f, -0.5f, -0.5f);
+		glVertex3f(-0.5f,  0.5f, -0.5f);
+		glVertex3f( 0.5f,  0.5f, -0.5f);
+		glVertex3f( 0.5f, -0.5f, -0.5f);
+
+		glColor3f(0.0f, 1.0f, 0.0f);
+		// LEFT
+		glVertex3f(-0.5f, -0.5f,  0.5f);
+		glVertex3f(-0.5f,  0.5f,  0.5f);
+		glVertex3f(-0.5f,  0.5f, -0.5f);
+		glVertex3f(-0.5f, -0.5f, -0.5f);
+		// RIGHT
+		glVertex3f( 0.5f, -0.5f, -0.5f);
+		glVertex3f( 0.5f,  0.5f, -0.5f);
+		glVertex3f( 0.5f,  0.5f,  0.5f);
+		glVertex3f( 0.5f, -0.5f,  0.5f);
+
+		glColor3f(0.0f, 0.0f, 1.0f);
+		// BOTTOM
+        glVertex3f(-0.5f, -0.5f,  0.5f);
+        glVertex3f(-0.5f, -0.5f, -0.5f);
+        glVertex3f( 0.5f, -0.5f, -0.5f);
+        glVertex3f( 0.5f, -0.5f,  0.5f);
+    glEnd();
+
+	glFlush();
+}
+
+
+int main(int argc, char** argv)
+{
+	init(argc, argv);
+	glutDisplayFunc(display);
+	glutMainLoop();	
+	return 0;
+}
+
+

Code/box/template_koordinatensystemUndPunkte.c

@@ -0,0 +1,184 @@
+#include <GL/glut.h>
+#include <string.h>
+#include <math.h>
+#include <stdio.h>
+
+#pragma warning(disable:4996)
+
+#define PI 3.14159265358979323846
+
+int width = 800;
+int height = 600;
+
+void init(int argc, char** argv) {
+	glutInit(&argc, argv);
+	glutInitDisplayMode(GLUT_SINGLE);
+	glutInitWindowSize(width, height);
+	glutInitWindowPosition(100, 100);
+	glViewport(0, 0, width, height);
+	glutCreateWindow("Programmieruebung Kreis-Plotter");
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	gluOrtho2D(0, width, 0, height);
+	glMatrixMode(GL_MODELVIEW);
+	glEnable(GL_POINT_SMOOTH);
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+}
+
+void drawCoordinateSystem(float* origin, int xLength, int yLength, int numTicksX, int numTicksY, float minX, float maxX, float minY, float maxY) {
+
+	float xTickDistance = (float) xLength / (float) numTicksX;
+	float yTickDistance = (float) yLength / (float) numTicksY;
+
+	int  k;
+	float j;
+
+	float resX, resY;
+
+	char label[10];
+
+	resX = (maxX - minX) / xLength;
+	resY = (maxY - minY) / yLength;
+
+	glColor3f(0.0, 0.0, 0.0);
+	/* drawing the coordinate system */
+	glBegin(GL_LINES);
+	// x axis
+	glVertex2f(origin[0], origin[1]);
+	glVertex2f(origin[0] + xLength, origin[1]);
+	// y axis
+	glVertex2f(origin[0], origin[1]);
+	glVertex2f(origin[0], origin[1] + yLength);
+	// arrow head at x axis
+	glVertex2f(origin[0] + xLength, origin[1]);
+	glVertex2f(origin[0] + xLength - 15, origin[1] - 10);
+	glVertex2f(origin[0] + xLength, origin[1]);
+	glVertex2f(origin[0] + xLength - 15, origin[1] + 10);
+	// arrow head at y axis
+	glVertex2f(origin[0], origin[1] + yLength);
+	glVertex2f(origin[0] - 10, origin[1] + yLength - 15);
+	glVertex2f(origin[0], origin[1] + yLength);
+	glVertex2f(origin[0] + 10, origin[1] + yLength - 15);
+	glEnd();
+
+	// drawing ticks at x axis
+	for (j = 0; j < xLength; j = j + xTickDistance) {
+		glBegin(GL_LINES);
+		glVertex2f(origin[0] + j, origin[1] - 5);
+		glVertex2f(origin[0] + j, origin[1] + 5);
+		glEnd();
+		sprintf(label, "%5.2f", minX + (j*resX));
+		glRasterPos2i((int) round(origin[0] + j - (8 * 5)), (int) round(origin[1] - 13 - 10));
+		for (k = 0; k < 5; k++) {
+			glutBitmapCharacter(GLUT_BITMAP_8_BY_13, label[k]);
+		}
+	}
+
+	// drawing ticks at y axis
+	for (j = 0; j < yLength; j = j + yTickDistance) {
+		glBegin(GL_LINES);
+		glVertex2f(origin[0] - 5, origin[1] + j);
+		glVertex2f(origin[0] + 5, origin[1] + j);
+		glEnd();
+		sprintf(label, "%5.2f", minY + (j*resY));
+		glRasterPos2i((int) round(origin[0] - (8 * 5) - 10), (int) round(origin[1] + j - 13 / 2));
+		for (k = 0; k < 5; k++) {
+			glutBitmapCharacter(GLUT_BITMAP_8_BY_13, label[k]);
+		}
+	}
+}
+
+
+void drawCircle(float origin[2], float center[2], float radius, GLint numPoints)
+{
+	//////////////////////////////////////////////////////////////////////////////////////////////
+	// - calculate numPoints points on the surface of the circle with given center and radius
+	//		hint: see circle equation in parametric form 
+	// - position points in the coordinate system starting at given origin
+	// - draw the points by OpenGL commands
+
+	
+	
+	
+	
+	
+	
+	
+	
+	
+	
+
+
+	//////////////////////////////////////////////////////////////////////////////////////////////
+}
+
+
+
+
+void display(void)
+{
+
+	int n;
+	int xTickDistance = 50;
+	int yTickDistance = 50;
+	int numPoints = 30;
+	float radius[] = { 50, 100, 150 };
+	float center[] = { 300, 200 };
+	float origin[] = { 100, 100 };
+	GLfloat c[] = { 0.0,0.0,0.0 };
+	int xLength = 600;
+	int yLength = 400;
+	float size = 2;
+	
+
+	/* settings for the coordinate system */
+	int numTicksX = 6;
+	int numTicksY = 4;
+	float minX = 0;
+	float maxX = 600;
+	float minY = 0;
+	float maxY = 400;
+
+
+	/* clearing the background color */
+	glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+
+	drawCoordinateSystem(origin, xLength, yLength, numTicksX, numTicksY, minX, maxX, minY, maxY);
+
+
+	for (n = 0; n < 3; n++) {
+
+		///////////////////////////////////////////////////////////////////////////////
+		// - set the point size different for each loop iteration
+		// - set the color different for each loop iteration
+
+	
+	
+	
+	
+	
+	
+
+
+		//////////////////////////////////////////////////////////////////////////////
+		drawCircle(origin, center, radius[n], numPoints);
+	}
+
+
+	glFlush();
+}
+
+
+int main(int argc, char** argv)
+{
+	init(argc, argv);
+
+	glutDisplayFunc(display);
+	glutMainLoop();
+	return 0;
+}
+
+

Code/hello_world/CMakeLists.txt

@@ -1,5 +0,0 @@
-cmake_minimum_required (VERSION 3.8)
-
-add_executable (hello_world helloWorld.c)
-target_include_directories(hello_world PRIVATE ${OPENGL_INCLUDE_DIRS}  ${GLUT_INCLUDE_DIRS} )
-target_link_libraries(hello_world ${OPENGL_LIBRARIES} ${GLUT_LIBRARY} )

Code/hello_world/helloWorld.c

@@ -1,8 +1,8 @@
 #include <GL/glut.h>
 #include <string.h>
 
-int width = 640;
+static int width = 640;
-int height = 480;
+static int height = 480;
 
 void init(int argc, char** argv)
 {
@@ -22,7 +22,7 @@ void init(int argc, char** argv)
 void display(void)
 {
     char* myText = "Hello World!";
-    int j;
+    unsigned long j;
 
     glClear(GL_COLOR_BUFFER_BIT);
     glColor3f(1.0, 0.0, 0.0);
@@ -36,7 +36,7 @@ void display(void)
 
     glColor3f(1.0, 1.0, 1.0);
     glRasterPos2i((width / 2) - (width / 4) + 10, (height / 2) - (height / 4) + 10);
-    for (j = 0; j < strlen(myText); j++) {
+    for (j = 0ul; j < strlen(myText); j++) {
         glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, myText[j]);
     }