BBC.rar_Bernstein_bezier bernstein

#include <stdlib.h> #include <stdio.h> #include <GL/glut.h> int antialiasing = 0; int BizierSize = 0; GLuint selectedPoint = ~0; int winWidth, winHeight; GLuint selectBuffer[64]; GLdouble modelMatrix[16], projMatrix[16]; GLint viewport[4]; static bool add_node=false; static bool del_node=false; static bool move_node=false; static int count=0; GLfloat BC[100][3]; GLfloat *Bizier = &BC[0][0]; void evaluateCurve(void) { glEnable(GL_MAP2_VERTEX_3); glMap1f(GL_MAP1_VERTEX_3, // Type of data generated 0.0f, // Lower u range 100.0f, // Upper u range 3, // Distance between points in the data BizierSize, // number of control points &BC[0][0]); // array of control points // Enable the evaluator glEnable(GL_MAP1_VERTEX_3); // Map a grid of 100 points from 0 to 100 glMapGrid1d(100,0.0,100.0); // Evaluate the grid, using lines glEvalMesh1(GL_LINE,0,100); } void drawControlPoints(void) { int i; // Counting variable // Set point size larger to make more visible glPointSize(5.0f); // Loop through all control points for this example for (i = 0; i < BizierSize; i++) { glLoadName(i); glBegin(GL_POINTS); glVertex2fv(&Bizier[i * 3]); glEnd(); } } void selectControlPoints(void) { int i; for (i = 0; i < BizierSize; i++) { glLoadName(i); glBegin(GL_POINTS); glVertex2fv(&Bizier[i * 3]); glEnd(); } } void display(void) { glClear(GL_COLOR_BUFFER_BIT); evaluateCurve(); drawControlPoints(); glutSwapBuffers(); } void ortho(void) { if (winWidth <= winHeight) glOrtho(-10.0, 10.0, -10.0 * (GLfloat) winHeight / (GLfloat) winWidth, 10.0 * (GLfloat) winHeight / (GLfloat) winWidth, -10.0, 10.0); else glOrtho(-10.0 * (GLfloat) winWidth / (GLfloat) winHeight, 10.0 * (GLfloat) winWidth / (GLfloat) winHeight, -10.0, 10.0, -10.0, 10.0); } GLuint pick(int x, int y) { int hits; (void) glRenderMode(GL_SELECT); glInitNames(); glPushName(~0); glMatrixMode(GL_PROJECTION); glPushMatrix(); glLoadIdentity(); gluPickMatrix(x, winHeight - y, 16.0, 16.0, viewport); ortho(); glMatrixMode(GL_MODELVIEW); selectControlPoints(); glMatrixMode(GL_PROJECTION); glPopMatrix(); glMatrixMode(GL_MODELVIEW); hits = glRenderMode(GL_RENDER); if (hits) { #ifdef DEBUG { unsigned int i; GLint names; GLuint *ptr; printf("hits = %d\n", hits); ptr = (GLuint *) selectBuffer; for (i = 0; i < hits; i++) { /* for each hit */ int j; names = *ptr; printf("number of names for hit = %d\n", *ptr); ptr++; printf(" z1 is %g;", (float) *ptr / 0xffffffff); ptr++; printf(" z2 is %g\n", (float) *ptr / 0xffffffff); ptr++; printf(" the name is "); for (j = 0; j < names; j++) { /* For each name. */ printf("%d ", *ptr); ptr++; } printf("\n"); } } #endif return selectBuffer[3]; } else return ~0; } void reshape(int w, int h) { glViewport(0, 0, w, h); winWidth = w; winHeight = h; glMatrixMode(GL_PROJECTION); glLoadIdentity(); ortho(); glGetDoublev(GL_PROJECTION_MATRIX, projMatrix); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glGetDoublev(GL_MODELVIEW_MATRIX, modelMatrix); viewport[0] = 0; viewport[1] = 0; viewport[2] = winWidth; viewport[3] = winHeight; } void mouse(int button, int state, int x, int y) { if (button == GLUT_LEFT_BUTTON) { if (state == GLUT_DOWN && move_node==true) selectedPoint = pick(x, y); else if(state == GLUT_DOWN && del_node==true) { selectedPoint = pick(x, y); for(int i = selectedPoint; i < BizierSize; i++) { Bizier[i * 3] = Bizier[i * 3 + 3]; Bizier[i * 3+1] = Bizier[i * 3 + 4]; Bizier[i * 3+2] = Bizier[i * 3 + 5]; } BizierSize--; del_node=false; glutPostRedisplay(); } else if(state == GLUT_DOWN && add_node==true) { GLdouble objx, objy, objz; gluUnProject(x, winHeight - y, 0, modelMatrix, projMatrix, viewport, &objx, &objy, &objz); BC[BizierSize][0] = objx; BC[BizierSize][1] = objy; BC[BizierSize][2] = 0.0; BizierSize++; glutPostRedisplay(); } else selectedPoint = -1; } } void motion(int x, int y) { GLdouble objx, objy, objz; if (selectedPoint != ~0) { gluUnProject(x, winHeight - y, 0, modelMatrix, projMatrix, viewport, &objx, &objy, &objz); BC[selectedPoint][0] = objx; BC[selectedPoint][1] = objy; glutPostRedisplay(); } } /* ARGSUSED1 */ static void keyboard(unsigned char key, int x, int y) { switch (key) { case 27: exit(0); } } enum { M_ADD_NODE, M_DEL_NODE, MOVE_NODE, M_QUIT }; void menu(int value) { switch (value) { case M_ADD_NODE: add_node=true; del_node=false; move_node=false; evaluateCurve(); break; case M_DEL_NODE: add_node=false; del_node=true; move_node=false; evaluateCurve(); break; case MOVE_NODE: add_node=false; del_node=false; move_node=true; break; case M_QUIT: exit(0); break; } glutPostRedisplay(); } int main(int argc, char **argv) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB); glutCreateWindow("editgrid"); glutReshapeFunc(reshape); glutDisplayFunc(display); glutMouseFunc(mouse); glutKeyboardFunc(keyboard); glutMotionFunc(motion); glutCreateMenu(menu); glutAddMenuEntry("Add Node", M_ADD_NODE); glutAddMenuEntry("Del Node", M_DEL_NODE); glutAddMenuEntry("Move Node", MOVE_NODE); glutAddMenuEntry("Quit", M_QUIT); glutAttachMenu(GLUT_RIGHT_BUTTON); glSelectBuffer(sizeof(selectBuffer), selectBuffer); // evaluateCurve(); glutMainLoop(); return 0; /* ANSI C requires main to return int. */ }