[OpenGL] Case Study 03: recursive program of three-dimensional Sierpinski embedding pad

// A.3 recursive program of three-dimensional Sierpinski embedding pad/* recursive subdivision of a tetrahedron to form 3D Sierpinski gasket * // * Number of recursive steps given on command line */# include <stdlib. h> # include <Gl/glut. h>/* Initial tetrahedron */glfloat V [4] [3] = {0.0, 0.0, 1.0}, {0.0, 0.942809,-0.33333}, {-0.816497, -0.471405,-0.333333}, {0.816497,-0.471405,-0.333333 }}; glfloat colors [4] [3] = {1.0, 0.0, 0.0}, {0.0, 1.0, 0.0}, {0.0, 0.0, 1.0 },{ 0.0, 0.0, 0.0 }}; int N; void triangle (glfloat * va, glfloat * Vb, glfloat * Vc) {glvertex3fv (VA ); glvertex3fv (VB); glvertex3fv (VC);} void Tetra (glfloat * a, glfloat * B, glfloat * C, glfloat * D) {glcolor3fv (colors [0]); triangle (A, B, C); glcolor3fv (colors [1]); triangle (A, C, D); glcolor3fv (colors [2]); triangle (A, D, b); glcolor3fv (colors [3]); triangle (B, D, C);} void divide_tetra (glfloat * a, glfloat * B, glfloat * C, glflo At * D, int m) {glfloat mid [6] [3]; Int J; If (M> 0) {/* compute six midpoints */For (j = 0; j <3; j ++) Mid [0] [J] = (a [J] + B [J])/2; for (j = 0; j <3; j ++) Mid [1] [J] = (a [J] + C [J])/2; for (j = 0; j <3; j ++) mid [2] [J] = (a [J] + d [J])/2; for (j = 0; j <3; j ++) mid [3] [J] = (B [J] + C [J])/2; for (j = 0; j <3; j ++) mid [4] [J] = (C [J] + d [J])/2; for (j = 0; j <3; j ++) mid [5] [J] = (B [J] + d [J])/2;/* create 4 tetrahedrons by subdivision */divide_tetra (A, mid [0], mid [1 ], Mid [2] m-1); divide_tetra (mid [0], B, mid [3], mid [5] m-1); divide_tetra (mid [1], mid [3], C, mid [4] m-1); divide_tetra (mid [2], mid [4], D, mid [5], m-1 );} else Tetra (A, B, C, D);/* draw tetrahedron at end of recursion */} void display (void) {glclear (gl_color_buffer_bit | gl_depth_buffer_bit ); glbegin (gl_triangles); divide_tetra (V [0], V [1], V [2], V [3], n); glend (); glflush ();} void myreshape (int w, int h) {glviewport (0, 0, W, H); glmatrixmode (gl_projection); glloadidentity (); If (W <= h) glortho (-2.0, 2.0,-2.0 * (glfloat) h/(glfloat) W, 2.0 * (glfloat) h/(glfloat) W,-10.0, 10.0); elseglortho (-2.0 * (glfloat) W/(glfloat) h, 2.0 * (glfloat) w/(glfloat) h,-2.0, 2.0,-10.0, 10.0); glmatrixmode (gl_modelview); glupostredisplay ();} void main (INT argc, char ** argv) {n = 10; // n = atoi (argv [1]);/* or set number of subdivision St EPS here * // note that an error is reported if the previous sentence is directly used in vs or VC ++, because you need to enter a parameter. // You can use the command prompt line to open the debug folder of the project in windows, and press shift to right-click // select to open the command prompt line at the current position. // Input: main.exe 10 //. main.exe is determined based on your own situation. The next 10 is the number of recursion. You can customize it. // The actual detection result is stuck when the number is greater than 15, if the number is greater than 20, the system will directly crash to the machine, such as gluinitdisplaymode (& argc, argv), gluinitdisplaymode (glu_single | glu_rgb | glu_depth), gluinitwindowsize (500,500 ); gludisplayfunc (Display); glable (gl_depth_test); glclearcolor (1.0, 1.0, 1.0, 1.0); glumainloop ();}