c++ - switch between glOrtho and gluPerspective -
i'm working in little opengl - glut program (i'm totally noob), , i'm having many problems switching between gluperspective , glortho pressing key (for example 'p').
i've take screenhots illustrate problem... using gluperspective , glortho
and here's code...
#if defined(__apple__) #include <opengl/opengl.h> #include <glut/glut.h> #else #include <gl/gl.h> #include <gl/greeglut.h> #endif #include <iostream> #include <math.h> #include "model.h" using namespace std; // actual vector representing camera\'s direction float lx = 0.0f,lz = -1.0f; // xz position of camera float x = 0.0f,z = 5.0f; // angle rotating triangle float angle = 0.0f; float fov = 45.0; model m; model m1; model m2; model m3; double maxx, maxy, maxz; double minx, miny, minz; double centx, centy, centz; double maxtam; bool persp = true; double min(double x, double y) { if(x < y) return x; return y; } double max(double x, double y) { if(x > y) return x; return y; } void setminmaxxyz(void) { maxx = minx = m.vertices()[0]; maxy = miny = m.vertices()[1]; maxz = minz = m.vertices()[2]; for(int = 3; < m.vertices().size(); += 3) { maxx = max(maxx,m.vertices()[i]); minx = min(minx,m.vertices()[i]); maxy = max(maxy,m.vertices()[i+1]); miny = min(miny,m.vertices()[i+1]); maxz = max(maxz,m.vertices()[i+2]); minz = min(minz,m.vertices()[i+2]); } centx = ((maxx - minx)/2) + minx; centy = ((maxy - miny)/2) + miny; centz = ((maxz - minz)/2) + minz; } void changeview(void) { int w = glutget(glut_window_width); int h = glutget(glut_window_height); float ratio = w * 1.0 / h; glmatrixmode(gl_projection); glloadidentity(); if(persp) gluperspective(fov, ratio, 0.1f, 100.0f); else glortho(-1,1,-1,1,-0.5,100.0); glmatrixmode(gl_modelview); } void changesize(int w, int h) { // prevent divide zero, when window short // (you cant make window of 0 width). if(h == 0) h = 1; if(w == 0) w = 1; float ratio = w * 1.0 / h; glmatrixmode(gl_projection); glloadidentity(); if(persp) gluperspective(fov, ratio, 0.1f, 100.0f); else glortho(-1,1,-1,1,0.1,100.0); glviewport(0,0,w,h); glmatrixmode(gl_modelview); glutpostredisplay(); } void renderscene(void) { glclear(gl_color_buffer_bit | gl_depth_buffer_bit); // reset transformations glloadidentity(); // posicionament de la càmera glulookat( x, 1.0f, z, x+lx, 1.0f, z+lz, 0.0f, 1.0f, 0.0f); glclearcolor(0.5,0.5,1.0,1.0); // dibuix terra glcolor3f(0.0f, 255.0f, 0.0f); glbegin(gl_quads); glvertex3f(-5.0f, 0.0f, -5.0f); glvertex3f(-5.0f, 0.0f, 5.0f); glvertex3f( 5.0f, 0.0f, 5.0f); glvertex3f( 5.0f, 0.0f, -5.0f); glend(); // models .obj (int = 0; < 3; ++i) { float transx, transy, transz; if(i == 0) { m = m1; transx = -1.25; transy = 0.5; transz = -2.0; } else if(i == 1) { m = m2; transx = -0.5; transy = 0.5; transz = 2.5; } else { m = m3; transx = 2.5; transy = 0.25; transz = -0.5; } setminmaxxyz(); maxtam = max(max(maxx - minx, maxy - miny), maxz - minz); glpushmatrix(); gltranslated(-(centx / maxtam), -(centy / maxtam), -(centz / maxtam)); gltranslated(transx,transy,transz); glscaled(1.0/maxtam,1.0/maxtam,1.0/maxtam); glbegin(gl_triangles); for(int = 0; < m.faces().size(); i++){ const face &f = m.faces()[i]; glcolor3f(materials[f.mat].diffuse[0],materials[f.mat].diffuse[1],materials[f.mat].diffuse[2]); for(int j = 0; j < 3; j++) glvertex3dv(&m.vertices()[f.v[j]]); } glend(); glpopmatrix(); } glutswapbuffers(); } void processkeys(unsigned char key, int x, int y) { if (key == 27) exit(0); else if(key == 'p'){ persp = not persp; changeview(); } } void processspecialkeys(int key, int xx, int yy) { float fraction = 0.1f; switch (key) { case glut_key_left : angle -= 0.01f; lx = sin(angle); lz = -cos(angle); break; case glut_key_right : angle += 0.01f; lx = sin(angle); lz = -cos(angle); break; case glut_key_up : x += lx * fraction; z += lz * fraction; break; case glut_key_down : x -= lx * fraction; z -= lz * fraction; break; } } void idle(void) { glutpostredisplay(); } void iniview(void) { int w = glutget(glut_window_width); int h = glutget(glut_window_height); float ratio = w * 1.0 / h; glmatrixmode(gl_projection); glloadidentity(); gluperspective(45.0f, ratio, 0.1f, 100.0f); //glortho(-1,1,-1,1,0.01,1000); glmatrixmode(gl_modelview); } int main(int argc, char **argv) { // init glut creació finestra glutinit(&argc, argv); glutinitdisplaymode(glut_depth | glut_double | glut_rgba); glutinitwindowposition(100,100); glutinitwindowsize(800,800); glutcreatewindow("idi: bloc 3 - càmeres perspectives"); // carregar models .obj m1.load("model/legoman-assegut.obj"); m2.load("model/shaun_hastings.obj"); m3.load("model/porsche.obj"); // crides glutdisplayfunc(renderscene); glutreshapefunc(changesize); glutidlefunc(idle); glutkeyboardfunc(processkeys); glutspecialfunc(processspecialkeys); iniview(); // opengl init glenable(gl_depth_test); // loop glutmainloop(); return 1; } it's supposed should see green "floor" in glortho view... i'm doing wrong??
ps. model objects .obj files delivered teacher.
edit:
finally, glortho works properly. now... i've got question, how can maximize window , (in glortho mode) image not deform??
in changesize() function... when i'm using gluperspective works fine, not glortho!!
the fact don't see floor orthographic projection expected given way set modelview matrix: happens because floor parallel xz plane - , view vector is, too.
// posicionament de la càmera glulookat( x, 1.0f, z, x+lx, 1.0f, z+lz, 0.0f, 1.0f, 0.0f); the first 3 arguments of glulookat xyz-components of camera position, next 3 arguments xyz of 'center of interest'. vector between 2 points view vector, , y-component 0, meaning parallel xz , floor.
if want see floor + orthographic projection, you'll have tilt camera looks down.
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