2025-04-27 07:49:33 -04:00

283 lines
10 KiB
C

/* $Revision: 1.4 $ */
/* compile: cc -o glxdino glxdino.c -lGLU -lGL -lX11 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h> /* for cos() and sin() */
#include <GL/glx.h> /* this includes the necessary X and gl.h headers */
#include <GL/glu.h>
typedef enum {
RESERVED, BODY_SIDE, BODY_EDGE, BODY_WHOLE, ARM_SIDE, ARM_EDGE, ARM_WHOLE,
LEG_SIDE, LEG_EDGE, LEG_WHOLE, EYE_SIDE, EYE_EDGE, EYE_WHOLE, DINOSAUR
} displayLists;
Display *dpy;
Window win;
GLfloat angle = 0.5; /* in radians */
GLboolean doubleBuffer = GL_TRUE, iconic = GL_FALSE, keepAspect = GL_FALSE;
int W = 300, H = 300;
XSizeHints sizeHints = {0};
GLdouble bodyWidth = 2.0;
int dblBuf[] = {GLX_DOUBLEBUFFER, GLX_RGBA, GLX_DEPTH_SIZE, 16, None};
GLfloat lightGreen[] = {0.1, 1.0, 0.3}, darkGreen[] = {0.0, 0.4, 0.1},
anotherGreen[] = {0.0, 0.8, 0.1}, bloodRed[] = {1.0, 0.0, 0.1};
GLfloat body[][2] = { {0, 3}, {1, 1}, {5, 1}, {8, 4}, {10, 4}, {11, 5}, {11, 11.5},
{13, 12}, {13, 13}, {10, 13.5}, {13, 14}, {13, 15}, {11, 16}, {8, 16}, {7, 15},
{7, 13}, {8, 12}, {7, 11}, {6, 6}, {4, 3}, {3, 2}, {1, 2}};
GLfloat arm[][2] = { {8, 10}, {9, 9}, {10, 9}, {13, 8}, {14, 9}, {16, 9}, {15, 9.5},
{16, 10}, {15, 10}, {15.5, 11}, {14.5, 10}, {14, 11}, {14, 10}, {13, 9}, {11, 11},
{9, 11}};
GLfloat leg[][2] = { {8, 6}, {8, 4}, {9, 3}, {9, 2}, {8, 1}, {8, 0.5}, {9, 0}, {12, 0},
{10, 1}, {10, 2}, {12, 4}, {11, 6}, {10, 7}, {9, 7}};
GLfloat eye[][2] = { {8.75, 15}, {9, 14.7}, {9.6, 14.7}, {10.1, 15}, {9.6, 15.25},
{9, 15.25}};
void
fatalError(char *message)
{
fprintf(stderr, "glxdino: %s\n", message);
exit(1);
}
void
extrudeSolidFromPolygon(GLfloat data[][2], unsigned int dataSize, GLdouble thickness, GLuint side,
GLuint edge, GLuint whole, GLfloat * sideColor, GLfloat * edgeColor)
{
static GLUtriangulatorObj *tobj = NULL;
GLdouble vertex[3];
int i;
if (tobj == NULL) {
tobj = gluNewTess(); /* create and initialize a GLU polygon tesselation object */
gluTessCallback(tobj, GLU_BEGIN, glBegin);
gluTessCallback(tobj, GLU_VERTEX, glVertex2fv); /* semi-tricky */
gluTessCallback(tobj, GLU_END, glEnd);
}
glNewList(side, GL_COMPILE);
gluBeginPolygon(tobj);
for (i = 0; i < dataSize / (2 * sizeof(GLfloat)); i++) {
vertex[0] = data[i][0]; vertex[1] = data[i][1]; vertex[2] = 0;
gluTessVertex(tobj, vertex, &data[i]);
}
gluEndPolygon(tobj);
glEndList();
glNewList(edge, GL_COMPILE);
glBegin(GL_QUAD_STRIP);
for (i = 0; i < dataSize / (2 * sizeof(GLfloat)); i++) {
vertex[0] = data[i][0]; vertex[1] = data[i][1]; vertex[2] = 0;
glVertex3dv(vertex);
vertex[2] = thickness;
glVertex3dv(vertex);
}
vertex[0] = data[0][0]; vertex[1] = data[0][1]; vertex[2] = 0;
glVertex3dv(vertex);
vertex[2] = thickness;
glVertex3dv(vertex);
glEnd();
glEndList();
glNewList(whole, GL_COMPILE);
glColor3fv(edgeColor);
glFrontFace(GL_CW);
glCallList(edge);
glColor3fv(sideColor);
glCallList(side);
glPushMatrix();
glTranslatef(0.0, 0.0, thickness);
glFrontFace(GL_CCW);
glCallList(side);
glPopMatrix();
glEndList();
}
void
makeDinosaur(void)
{
GLfloat bodyWidth = 3.0;
extrudeSolidFromPolygon(body, sizeof(body), bodyWidth, BODY_SIDE, BODY_EDGE,
BODY_WHOLE, lightGreen, darkGreen);
extrudeSolidFromPolygon(arm, sizeof(arm), bodyWidth / 4, ARM_SIDE, ARM_EDGE,
ARM_WHOLE, darkGreen, anotherGreen);
extrudeSolidFromPolygon(leg, sizeof(leg), bodyWidth / 2, LEG_SIDE, LEG_EDGE,
LEG_WHOLE, darkGreen, anotherGreen);
extrudeSolidFromPolygon(eye, sizeof(eye), bodyWidth + 0.2, EYE_SIDE, EYE_EDGE,
EYE_WHOLE, bloodRed, bloodRed);
glNewList(DINOSAUR, GL_COMPILE);
glCallList(BODY_WHOLE);
glPushMatrix();
glTranslatef(0.0, 0.0, -0.1);
glCallList(EYE_WHOLE);
glTranslatef(0.0, 0.0, bodyWidth + 0.1);
glCallList(ARM_WHOLE);
glCallList(LEG_WHOLE);
glTranslatef(0.0, 0.0, -bodyWidth - bodyWidth / 4);
glCallList(ARM_WHOLE);
glTranslatef(0.0, 0.0, -bodyWidth / 4);
glCallList(LEG_WHOLE);
glPopMatrix();
glEndList();
}
void
redraw(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glCallList(DINOSAUR);
if (doubleBuffer) glXSwapBuffers(dpy, win); /* buffer swap does implicit glFlush */
else glFlush(); /* explicit flush for single buffered case */
}
void
main(int argc, char **argv)
{
XVisualInfo *vi;
Colormap cmap;
XSetWindowAttributes swa;
XWMHints *wmHints;
Atom wmDeleteWindow;
GLXContext cx;
XEvent event;
GLboolean needRedraw = GL_FALSE, recalcModelView = GL_TRUE;
char *display = NULL, *geometry = NULL;
int dummy, flags, x, y, width, height, lastX, i;
/*** (1) process normal X command line arguments ***/
for (i = 1; i < argc; i++) {
if (!strcmp(argv[i], "-geometry")) {
i++;
if (i >= argc) fatalError("follow -geometry option with geometry parameter");
geometry = argv[i];
} else if (!strcmp(argv[i], "-display")) {
i++;
if (i >= argc) fatalError("follow -display option with display parameter");
display = argv[i];
} else if (!strcmp(argv[i], "-iconic")) iconic = GL_TRUE;
else if (!strcmp(argv[i], "-keepaspect")) keepAspect = GL_TRUE;
else fatalError("bad option");
}
/*** (2) open a connection to the X server ***/
dpy = XOpenDisplay(display);
if (dpy == NULL) fatalError("could not open display");
/*** (3) make sure OpenGL's GLX extension supported ***/
if (!glXQueryExtension(dpy, &dummy, &dummy)) fatalError("X server has no OpenGL GLX extension");
/*** (4) find an appropriate visual ***/
/* find an OpenGL-capable RGB visual with depth buffer */
vi = glXChooseVisual(dpy, DefaultScreen(dpy), dblBuf);
if (vi == NULL) {
vi = glXChooseVisual(dpy, DefaultScreen(dpy), &dblBuf[1]);
if (vi == NULL) fatalError("no RGB visual with depth buffer");
doubleBuffer = GL_FALSE;
}
if (vi->class != TrueColor) fatalError("TrueColor visual required for this program");
/*** (5) create an OpenGL rendering context ***/
/* create an OpenGL rendering context */
cx = glXCreateContext(dpy, vi, /* no sharing of display lists */ None,
/* direct rendering if possible */ GL_TRUE);
if (cx == NULL) fatalError("could not create rendering context");
/*** (6) create an X window with the selected visual and right properties ***/
flags = XParseGeometry(geometry, &x, &y, (unsigned int *) &width, (unsigned int *) &height);
if (WidthValue & flags) {
sizeHints.flags |= USSize;
sizeHints.width = width;
W = width;
}
if (HeightValue & flags) {
sizeHints.flags |= USSize;
sizeHints.height = height;
H = height;
}
if (XValue & flags) {
if (XNegative & flags) x = DisplayWidth(dpy, DefaultScreen(dpy)) + x - sizeHints.width;
sizeHints.flags |= USPosition;
sizeHints.x = x;
}
if (YValue & flags) {
if (YNegative & flags) y = DisplayHeight(dpy, DefaultScreen(dpy)) + y - sizeHints.height;
sizeHints.flags |= USPosition;
sizeHints.y = y;
}
if (keepAspect) {
sizeHints.flags |= PAspect;
sizeHints.min_aspect.x = sizeHints.max_aspect.x = W;
sizeHints.min_aspect.y = sizeHints.max_aspect.y = H;
}
/* create an X colormap since probably not using default visual */
cmap = XCreateColormap(dpy, RootWindow(dpy, vi->screen), vi->visual, AllocNone);
swa.colormap = cmap;
swa.border_pixel = 0;
swa.event_mask = ExposureMask | ButtonPressMask | Button1MotionMask | StructureNotifyMask;
win = XCreateWindow(dpy, RootWindow(dpy, vi->screen), sizeHints.x, sizeHints.y, W, H,
0, vi->depth, InputOutput, vi->visual,
CWBorderPixel|CWColormap|CWEventMask, &swa);
XSetStandardProperties(dpy, win, "OpenGLosaurus", "glxdino", None, argv, argc, &sizeHints);
wmHints = XAllocWMHints();
wmHints->initial_state = iconic ? IconicState : NormalState;
wmHints->flags = StateHint;
XSetWMHints(dpy, win, wmHints);
wmDeleteWindow = XInternAtom(dpy, "WM_DELETE_WINDOW", False);
XSetWMProtocols(dpy, win, &wmDeleteWindow, 1);
/*** (7) bind the rendering context to the window ***/
glXMakeCurrent(dpy, win, cx);
/*** (8) make the desired display lists ***/
makeDinosaur();
/*** (9) request the X window to be displayed on the screen ***/
XMapWindow(dpy, win);
/*** (10) configure the OpenGL context for rendering ***/
glEnable(GL_CULL_FACE); /* ~50% better perfomance than non-face culled on Starter Indigo */
glEnable(GL_DEPTH_TEST); /* enable depth buffering */
glClearColor(0.0, 0.0, 0.0, 0.0); /* frame buffer clears should be to black */
glMatrixMode(GL_PROJECTION); /* set up projection transform */
glLoadIdentity();
gluPerspective(40.0, 1, 1.0, 40.0);
glMatrixMode(GL_MODELVIEW); /* now change to modelview */
/*** (11) dispatch X events ***/
while (1) {
do {
XNextEvent(dpy, &event);
switch (event.type) {
case ButtonPress:
lastX = event.xbutton.x;
break;
case MotionNotify:
recalcModelView = GL_TRUE;
angle += (lastX - event.xmotion.x) / (GLfloat) 50; /* fifty is empirical scale factor */
lastX = event.xmotion.x;
break;
case ConfigureNotify:
glViewport(0, 0, event.xconfigure.width, event.xconfigure.height);
/* fall through... */
case Expose:
needRedraw = GL_TRUE;
break;
case ClientMessage:
if (event.xclient.data.l[0] == wmDeleteWindow) exit(0);
break;
}
} while (XPending(dpy));/* loop to compress events */
if (recalcModelView) {
/* reset modelview matrix to the identity matrix */
glLoadIdentity();
gluLookAt(30 * sin(angle), 0, 30 * cos(angle), 0, 0, 0, 0, 1, 0);
glTranslatef(-8, -8, -bodyWidth / 2);
recalcModelView = GL_FALSE;
needRedraw = GL_TRUE;
}
if (needRedraw) {
redraw();
needRedraw = GL_FALSE;
}
}
}