#include <stdio.h>
#include <string.h>
#include <GL/glut.h>
+#include "../XGL/xgl.h"
#include "obj.h"
#include "scenery.h"
float normals[MAXNODES][3];
+/* given three points defining a triangle, calculate the normal */
+void calc_normal(float p1[3], float p2[3], float p3[3], double normal[3])
+{
+ double v1[3], v2[3];
+ float temp;
+
+ v1[0] = p2[0] - p1[0]; v1[1] = p2[1] - p1[1]; v1[2] = p2[2] - p1[2];
+ v2[0] = p3[0] - p1[0]; v2[1] = p3[1] - p1[1]; v2[2] = p3[2] - p1[2];
+
+ MAT3cross_product(normal, v1, v2);
+ MAT3_NORMALIZE_VEC(normal,temp);
+
+ /* printf(" Normal = %.2f %.2f %.2f\n", normal[0], normal[1], normal[2]);*/
+}
+
+
/* Load a .obj file and generate the GL call list */
GLint fgObjLoad(char *path) {
- char line[256], winding[256];
+ char line[256], winding_str[256];
double v1[3], v2[3], approx_normal[3], dot_prod, temp;
struct fgCartesianPoint ref;
GLint area;
FILE *f;
int first, ncount, vncount, n1, n2, n3, n4;
- int i;
+ static int use_vertex_norms = 1;
+ int i, winding;
+ int last1, last2, odd;
if ( (f = fopen(path, "r")) == NULL ) {
printf("Cannot open file: %s\n", path);
exit(-1);
}
- area = glGenLists(1);
- glNewList(area, GL_COMPILE);
+ area = xglGenLists(1);
+ xglNewList(area, GL_COMPILE);
first = 1;
ncount = 1;
while ( fgets(line, 250, f) != NULL ) {
if ( line[0] == '#' ) {
/* comment -- ignore */
+ } else if ( line[0] == '\n' ) {
+ /* empty line -- ignore */
} else if ( strncmp(line, "v ", 2) == 0 ) {
/* node (vertex) */
if ( ncount < MAXNODES ) {
exit(-1);
}
} else if ( strncmp(line, "winding ", 8) == 0 ) {
- sscanf(line+8, "%s", winding);
- printf("WINDING = %s\n", winding);
+ sscanf(line+8, "%s", winding_str);
+ printf(" WINDING = %s\n", winding_str);
- /* can't call glFrontFace() between glBegin() & glEnd() */
- glEnd();
+ /* can't call xglFrontFace() between xglBegin() & xglEnd() */
+ xglEnd();
first = 1;
- if ( strcmp(winding, "cw") == 0 ) {
- glFrontFace( GL_CW );
+ if ( strcmp(winding_str, "cw") == 0 ) {
+ xglFrontFace( GL_CW );
+ winding = 0;
} else {
- glFrontFace ( GL_CCW );
+ xglFrontFace ( GL_CCW );
+ winding = 1;
}
} else if ( line[0] == 't' ) {
/* start a new triangle strip */
if ( !first ) {
/* close out the previous structure and start the next */
- glEnd();
+ xglEnd();
} else {
first = 0;
}
- /* printf("new tri strip = %s", line); */
+ /* printf(" new tri strip = %s", line); */
sscanf(line, "t %d %d %d %d\n", &n1, &n2, &n3, &n4);
/* printf("(t) = "); */
- /* try to get the proper rotation by calculating an
- * approximate normal and seeing if it is close to the
- * precalculated normal */
- /*v1[0] = nodes[n2][0] - nodes[n1][0];
- v1[1] = nodes[n2][1] - nodes[n1][1];
- v1[2] = nodes[n2][2] - nodes[n1][2];
- v2[0] = nodes[n3][0] - nodes[n1][0];
- v2[1] = nodes[n3][1] - nodes[n1][1];
- v2[2] = nodes[n3][2] - nodes[n1][2];
- MAT3cross_product(approx_normal, v1, v2);
- MAT3_NORMALIZE_VEC(approx_normal,temp);
- printf("Approx normal = %.2f %.2f %.2f\n", approx_normal[0],
- approx_normal[1], approx_normal[2]);
- dot_prod = MAT3_DOT_PRODUCT(normals[n1], approx_normal);
- printf("Dot product = %.4f\n", dot_prod); */
- /* angle = acos(dot_prod); */
- /* printf("Normal ANGLE = %.3f rads.\n", angle); */
-
- /* if ( dot_prod < -0.5 ) {
- glFrontFace( GL_CW );
+ xglBegin(GL_TRIANGLE_STRIP);
+
+ if ( winding ) {
+ odd = 1;
} else {
- glFrontFace( GL_CCW );
- } */
+ odd = 0;
+ }
- glBegin(GL_TRIANGLE_STRIP);
+ if ( use_vertex_norms ) {
+ xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
+ xglVertex3d(nodes[n1][0] - ref.x, nodes[n1][1] - ref.y,
+ nodes[n1][2] - ref.z);
- glNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
- glVertex3d(nodes[n1][0] - ref.x, nodes[n1][1] - ref.y,
- nodes[n1][2] - ref.z);
+ xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
+ xglVertex3d(nodes[n2][0] - ref.x, nodes[n2][1] - ref.y,
+ nodes[n2][2] - ref.z);
- glNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
- glVertex3d(nodes[n2][0] - ref.x, nodes[n2][1] - ref.y,
- nodes[n2][2] - ref.z);
+ xglNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
+ xglVertex3d(nodes[n3][0] - ref.x, nodes[n3][1] - ref.y,
+ nodes[n3][2] - ref.z);
+ } else {
+ if ( odd ) {
+ calc_normal(nodes[n1], nodes[n2], nodes[n3], approx_normal);
+ } else {
+ calc_normal(nodes[n2], nodes[n1], nodes[n3], approx_normal);
+ }
+ xglNormal3dv(approx_normal);
+
+ xglVertex3d(nodes[n1][0] - ref.x, nodes[n1][1] - ref.y,
+ nodes[n1][2] - ref.z);
+ xglVertex3d(nodes[n2][0] - ref.x, nodes[n2][1] - ref.y,
+ nodes[n2][2] - ref.z);
+ xglVertex3d(nodes[n3][0] - ref.x, nodes[n3][1] - ref.y,
+ nodes[n3][2] - ref.z);
+ }
- glNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
- glVertex3d(nodes[n3][0] - ref.x, nodes[n3][1] - ref.y,
- nodes[n3][2] - ref.z);
+ odd = 1 - odd;
+ last1 = n2;
+ last2 = n3;
if ( n4 > 0 ) {
- glNormal3d(normals[n4][0], normals[n4][1], normals[n4][2]);
- glVertex3d(nodes[n4][0] - ref.x, nodes[n4][1] - ref.y,
- nodes[n4][2] - ref.z);
+ if ( use_vertex_norms ) {
+ xglNormal3d(normals[n4][0], normals[n4][1], normals[n4][2]);
+ } else {
+ calc_normal(nodes[n3], nodes[n2], nodes[n4], approx_normal);
+ xglNormal3dv(approx_normal);
+ }
+ xglVertex3d(nodes[n4][0] - ref.x, nodes[n4][1] - ref.y,
+ nodes[n4][2] - ref.z);
+
+ odd = 1 - odd;
+ last1 = n3;
+ last2 = n4;
}
} else if ( line[0] == 'f' ) {
/* unoptimized face */
if ( !first ) {
/* close out the previous structure and start the next */
- glEnd();
+ xglEnd();
} else {
first = 0;
}
- glBegin(GL_TRIANGLES);
+ xglBegin(GL_TRIANGLES);
/* printf("new triangle = %s", line);*/
sscanf(line, "f %d %d %d\n", &n1, &n2, &n3);
- glNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
- glVertex3d(nodes[n1][0] - ref.x, nodes[n1][1] - ref.y,
- nodes[n1][2] - ref.z);
+ xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
+ xglVertex3d(nodes[n1][0] - ref.x, nodes[n1][1] - ref.y,
+ nodes[n1][2] - ref.z);
- glNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
- glVertex3d(nodes[n2][0] - ref.x, nodes[n2][1] - ref.y,
- nodes[n2][2] - ref.z);
+ xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
+ xglVertex3d(nodes[n2][0] - ref.x, nodes[n2][1] - ref.y,
+ nodes[n2][2] - ref.z);
- glNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
- glVertex3d(nodes[n3][0] - ref.x, nodes[n3][1] - ref.y,
- nodes[n3][2] - ref.z);
+ xglNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
+ xglVertex3d(nodes[n3][0] - ref.x, nodes[n3][1] - ref.y,
+ nodes[n3][2] - ref.z);
} else if ( line[0] == 'q' ) {
/* continue a triangle strip */
n1 = n2 = 0;
sscanf(line, "q %d %d\n", &n1, &n2);
/* printf("read %d %d\n", n1, n2); */
- glNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
- glVertex3d(nodes[n1][0] - ref.x, nodes[n1][1] - ref.y,
- nodes[n1][2] - ref.z);
+ if ( use_vertex_norms ) {
+ xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
+ } else {
+ if ( odd ) {
+ calc_normal(nodes[last1], nodes[last2], nodes[n1],
+ approx_normal);
+ } else {
+ calc_normal(nodes[last2], nodes[last1], nodes[n1],
+ approx_normal);
+ }
+ xglNormal3dv(approx_normal);
+ }
+
+ xglVertex3d(nodes[n1][0] - ref.x, nodes[n1][1] - ref.y,
+ nodes[n1][2] - ref.z);
+
+ odd = 1 - odd;
+ last1 = last2;
+ last2 = n1;
if ( n2 > 0 ) {
/* printf(" (cont)\n"); */
- glNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
- glVertex3d(nodes[n2][0] - ref.x, nodes[n2][1] - ref.y,
- nodes[n2][2] - ref.z);
+
+ if ( use_vertex_norms ) {
+ xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
+ } else {
+ if ( odd ) {
+ calc_normal(nodes[last1], nodes[last2], nodes[n2],
+ approx_normal);
+ } else {
+ calc_normal(nodes[last2], nodes[last1], nodes[n2],
+ approx_normal);
+ }
+ xglNormal3dv(approx_normal);
+ }
+
+ xglVertex3d(nodes[n2][0] - ref.x, nodes[n2][1] - ref.y,
+ nodes[n2][2] - ref.z);
+
+ odd = 1 -odd;
+ last1 = last2;
+ last2 = n2;
}
} else {
printf("Unknown line in %s = %s\n", path, line);
}
}
- glEnd();
+ xglEnd();
/* Draw normal vectors (for visually verifying normals)*/
/*
- glBegin(GL_LINES);
- glColor3f(0.0, 0.0, 0.0);
+ xglBegin(GL_LINES);
+ xglColor3f(0.0, 0.0, 0.0);
for ( i = 0; i < ncount; i++ ) {
- glVertex3d(nodes[i][0] - ref.x,
- nodes[i][1] - ref.y,
- nodes[i][2] - ref.z);
- glVertex3d(nodes[i][0] - ref.x + 500*normals[i][0],
- nodes[i][1] - ref.y + 500*normals[i][1],
- nodes[i][2] - ref.z + 500*normals[i][2]);
+ xglVertex3d(nodes[i][0] - ref.x,
+ nodes[i][1] - ref.y,
+ nodes[i][2] - ref.z);
+ xglVertex3d(nodes[i][0] - ref.x + 500*normals[i][0],
+ nodes[i][1] - ref.y + 500*normals[i][1],
+ nodes[i][2] - ref.z + 500*normals[i][2]);
}
- glEnd();
+ xglEnd();
*/
- glEndList();
+ xglFrontFace ( GL_CCW );
+
+ xglEndList();
fclose(f);
/* $Log$
-/* Revision 1.10 1997/12/12 21:41:28 curt
-/* More light/material property tweaking ... still a ways off.
+/* Revision 1.15 1997/12/30 20:47:51 curt
+/* Integrated new event manager with subsystem initializations.
/*
+ * Revision 1.14 1997/12/30 01:38:46 curt
+ * Switched back to per vertex normals and smooth shading for terrain.
+ *
+ * Revision 1.13 1997/12/18 23:32:36 curt
+ * First stab at sky dome actually starting to look reasonable. :-)
+ *
+ * Revision 1.12 1997/12/17 23:13:47 curt
+ * Began working on rendering the sky.
+ *
+ * Revision 1.11 1997/12/15 23:55:01 curt
+ * Add xgl wrappers for debugging.
+ * Generate terrain normals on the fly.
+ *
+ * Revision 1.10 1997/12/12 21:41:28 curt
+ * More light/material property tweaking ... still a ways off.
+ *
* Revision 1.9 1997/12/12 19:52:57 curt
* Working on lightling and material properties.
*