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Diffstat (limited to 'progs/demos/reflect.c')
| -rw-r--r-- | progs/demos/reflect.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/progs/demos/reflect.c b/progs/demos/reflect.c new file mode 100644 index 0000000000..d941a73c60 --- /dev/null +++ b/progs/demos/reflect.c @@ -0,0 +1,435 @@ +/* $Id: reflect.c,v 1.1 1999/08/19 00:55:40 jtg Exp $ */ + +/* + * Demo of a reflective, texture-mapped surface with OpenGL. + * Brian Paul August 14, 1995 This file is in the public domain. + * + * Hardware texture mapping is highly recommended! + * + * The basic steps are: + * 1. Render the reflective object (a polygon) from the normal viewpoint, + * setting the stencil planes = 1. + * 2. Render the scene from a special viewpoint: the viewpoint which + * is on the opposite side of the reflective plane. Only draw where + * stencil = 1. This draws the objects in the reflective surface. + * 3. Render the scene from the original viewpoint. This draws the + * objects in the normal fashion. Use blending when drawing + * the reflective, textured surface. + * + * This is a very crude demo. It could be much better. + */ + +/* + * Dirk Reiners (reiners@igd.fhg.de) made some modifications to this code. + * + * August 1996 - A few optimizations by Brian + */ + +/* + * April, 1997 - Added Mark Kilgard's changes. + */ + +/* + * $Log: reflect.c,v $ + * Revision 1.1 1999/08/19 00:55:40 jtg + * Initial revision + * + * Revision 3.4 1999/03/28 18:22:05 brianp + * minor clean-up + * + * Revision 3.3 1998/11/22 02:54:29 brianp + * only draw one stack for gluCylinders + * + * Revision 3.2 1998/11/19 02:53:48 brianp + * changed texture image and background color + * + * Revision 3.1 1998/11/05 04:34:04 brianp + * moved image files to ../images/ directory + * + * Revision 3.0 1998/02/14 18:42:29 brianp + * initial rev + * + */ + + +#define USE_ZBUFFER + + +/* OK, without hardware support this is overkill. */ +#define USE_TEXTURE + +#include <math.h> +#include <stdio.h> +#include <stdlib.h> +#include "GL/glut.h" + +#include "../util/readtex.c" /* a hack, I know */ + + +#define DEG2RAD (3.14159/180.0) + + +#define TABLE_TEXTURE "../images/tile.rgb" + +static int ImgWidth, ImgHeight; +static GLenum ImgFormat; +static GLubyte *Image = NULL; + +#define MAX_OBJECTS 2 + +static GLint table_list; +static GLint objects_list[MAX_OBJECTS]; + + +static GLfloat xrot, yrot; +static GLfloat spin; + + + +static void make_table( void ) +{ + static GLfloat table_mat[] = { 1.0, 1.0, 1.0, 0.6 }; + static GLfloat gray[] = { 0.4, 0.4, 0.4, 1.0 }; + + table_list = glGenLists(1); + glNewList( table_list, GL_COMPILE ); + + /* load table's texture */ + glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, table_mat ); +/* glMaterialfv( GL_FRONT, GL_EMISSION, gray );*/ + glMaterialfv( GL_FRONT, GL_DIFFUSE, table_mat ); + glMaterialfv( GL_FRONT, GL_AMBIENT, gray ); + + /* draw textured square for the table */ + glPushMatrix(); + glScalef( 4.0, 4.0, 4.0 ); + glBegin( GL_POLYGON ); + glNormal3f( 0.0, 1.0, 0.0 ); + glTexCoord2f( 0.0, 0.0 ); glVertex3f( -1.0, 0.0, 1.0 ); + glTexCoord2f( 1.0, 0.0 ); glVertex3f( 1.0, 0.0, 1.0 ); + glTexCoord2f( 1.0, 1.0 ); glVertex3f( 1.0, 0.0, -1.0 ); + glTexCoord2f( 0.0, 1.0 ); glVertex3f( -1.0, 0.0, -1.0 ); + glEnd(); + glPopMatrix(); + + glDisable( GL_TEXTURE_2D ); + + glEndList(); +} + + +static void make_objects( void ) +{ + GLUquadricObj *q; + + static GLfloat cyan[] = { 0.0, 1.0, 1.0, 1.0 }; + static GLfloat green[] = { 0.2, 1.0, 0.2, 1.0 }; + static GLfloat black[] = { 0.0, 0.0, 0.0, 0.0 }; + + q = gluNewQuadric(); + gluQuadricDrawStyle( q, GLU_FILL ); + gluQuadricNormals( q, GLU_SMOOTH ); + + objects_list[0] = glGenLists(1); + glNewList( objects_list[0], GL_COMPILE ); + glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, cyan ); + glMaterialfv( GL_FRONT, GL_EMISSION, black ); + gluCylinder( q, 0.5, 0.5, 1.0, 15, 1 ); + glEndList(); + + objects_list[1] = glGenLists(1); + glNewList( objects_list[1], GL_COMPILE ); + glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green ); + glMaterialfv( GL_FRONT, GL_EMISSION, black ); + gluCylinder( q, 1.5, 0.0, 2.5, 15, 1 ); + glEndList(); +} + + +static GLfloat light_pos[] = { 0.0, 20.0, 0.0, 1.0 }; + +static void init( void ) +{ + make_table(); + make_objects(); + + /* Setup texture */ +#ifdef USE_TEXTURE + + Image = LoadRGBImage( TABLE_TEXTURE, &ImgWidth, &ImgHeight, &ImgFormat ); + if (!Image) { + printf("Couldn't read %s\n", TABLE_TEXTURE); + exit(0); + } + + gluBuild2DMipmaps(GL_TEXTURE_2D, 3, ImgWidth, ImgHeight, + ImgFormat, GL_UNSIGNED_BYTE, Image); + + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST ); +#endif + + + xrot = 30.0; + yrot = 50.0; + spin = 0.0; + +#ifndef USE_ZBUFFER + glEnable( GL_CULL_FACE ); +#endif + + glShadeModel( GL_FLAT ); + + glEnable( GL_LIGHT0 ); + glEnable( GL_LIGHTING ); + + glClearColor( 0.5, 0.5, 0.9, 1.0 ); + + glEnable( GL_NORMALIZE ); +} + + + +static void reshape(int w, int h) +{ + GLfloat aspect = (float) w / (float) h; + + glViewport(0, 0, w, h); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + glFrustum( -aspect, aspect, -1.0, 1.0, 4.0, 300.0 ); + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); +} + + + +static void draw_objects( GLfloat eyex, GLfloat eyey, GLfloat eyez ) +{ + (void) eyex; + (void) eyey; + (void) eyez; +#ifndef USE_ZBUFFER + if (eyex<0.5) + { +#endif + glPushMatrix(); + glTranslatef( 1.0, 1.5, 0.0 ); + glRotatef( spin, 1.0, 0.5, 0.0 ); + glRotatef( 0.5*spin, 0.0, 0.5, 1.0 ); + glCallList( objects_list[0] ); + glPopMatrix(); + + glPushMatrix(); + glTranslatef( -1.0, 0.85+3.0*fabs( cos(0.01*spin) ), 0.0 ); + glRotatef( 0.5*spin, 0.0, 0.5, 1.0 ); + glRotatef( spin, 1.0, 0.5, 0.0 ); + glScalef( 0.5, 0.5, 0.5 ); + glCallList( objects_list[1] ); + glPopMatrix(); +#ifndef USE_ZBUFFER + } + else + { + glPushMatrix(); + glTranslatef( -1.0, 0.85+3.0*fabs( cos(0.01*spin) ), 0.0 ); + glRotatef( 0.5*spin, 0.0, 0.5, 1.0 ); + glRotatef( spin, 1.0, 0.5, 0.0 ); + glScalef( 0.5, 0.5, 0.5 ); + glCallList( objects_list[1] ); + glPopMatrix(); + + glPushMatrix(); + glTranslatef( 1.0, 1.5, 0.0 ); + glRotatef( spin, 1.0, 0.5, 0.0 ); + glRotatef( 0.5*spin, 0.0, 0.5, 1.0 ); + glCallList( objects_list[0] ); + glPopMatrix(); + } +#endif +} + + + +static void draw_table( void ) +{ + glCallList( table_list ); +} + + + +static void draw_scene( void ) +{ + GLfloat dist = 20.0; + GLfloat eyex, eyey, eyez; + + glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); + + + eyex = dist * cos(yrot*DEG2RAD) * cos(xrot*DEG2RAD); + eyez = dist * sin(yrot*DEG2RAD) * cos(xrot*DEG2RAD); + eyey = dist * sin(xrot*DEG2RAD); + + /* view from top */ + glPushMatrix(); + gluLookAt( eyex, eyey, eyez, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0 ); + + glLightfv( GL_LIGHT0, GL_POSITION, light_pos ); + + /* draw table into stencil planes */ + glEnable( GL_STENCIL_TEST ); +#ifdef USE_ZBUFFER + glDisable( GL_DEPTH_TEST ); +#endif + glStencilFunc( GL_ALWAYS, 1, 0xffffffff ); + glStencilOp( GL_REPLACE, GL_REPLACE, GL_REPLACE ); + glColorMask( GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE ); + draw_table(); + glColorMask( GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE ); + +#ifdef USE_ZBUFFER + glEnable( GL_DEPTH_TEST ); +#endif + + + /* render view from below (reflected viewport) */ + /* only draw where stencil==1 */ + if (eyey>0.0) { + glPushMatrix(); + + glStencilFunc( GL_EQUAL, 1, 0xffffffff ); /* draw if ==1 */ + glStencilOp( GL_KEEP, GL_KEEP, GL_KEEP ); + glScalef( 1.0, -1.0, 1.0 ); + + /* Reposition light in reflected space. */ + glLightfv(GL_LIGHT0, GL_POSITION, light_pos); + + draw_objects(eyex, eyey, eyez); + glPopMatrix(); + + /* Restore light's original unreflected position. */ + glLightfv(GL_LIGHT0, GL_POSITION, light_pos); + } + + glDisable( GL_STENCIL_TEST ); + + glEnable( GL_BLEND ); + glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ); + +#ifdef USE_TEXTURE + glEnable( GL_TEXTURE_2D ); +#endif + draw_table(); + glDisable( GL_TEXTURE_2D ); + glDisable( GL_BLEND ); + + /* view from top */ + glPushMatrix(); + + draw_objects(eyex, eyey, eyez); + + glPopMatrix(); + + glPopMatrix(); + + glutSwapBuffers(); +} + + + +#if 0 +void draw_scene(void) +{ + GLfloat dist = 20.0; + GLfloat eyex, eyey, eyez; + + glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); + + + eyex = dist * cos(yrot*DEG2RAD) * cos(xrot*DEG2RAD); + eyez = dist * sin(yrot*DEG2RAD) * cos(xrot*DEG2RAD); + eyey = dist * sin(xrot*DEG2RAD); + + /* view from top */ + glPushMatrix(); + gluLookAt( eyex, eyey, eyez, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0 ); + + draw_table(); + + glPopMatrix(); + + glutSwapBuffers(); +} +#endif + + +static void Key( unsigned char key, int x, int y ) +{ + (void) x; + (void) y; + if (key==27) + exit(0); +} + + +static void SpecialKey( int key, int x, int y ) +{ + (void) x; + (void) y; + switch (key) { + case GLUT_KEY_UP: + xrot += 3.0; +#ifndef USE_ZBUFFER + if ( xrot > 180 ) xrot = 180; +#endif + break; + case GLUT_KEY_DOWN: + xrot -= 3.0; +#ifndef USE_ZBUFFER + if ( xrot < 0 ) xrot = 0; +#endif + break; + case GLUT_KEY_LEFT: + yrot += 3.0; + break; + case GLUT_KEY_RIGHT: + yrot -= 3.0; + break; + } + glutPostRedisplay(); +} + + + +static void idle( void ) +{ + spin += 2.0; + yrot += 3.0; + glutPostRedisplay(); +} + + + +int main( int argc, char *argv[] ) +{ + glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB +#ifdef USE_ZBUFFER + | GLUT_DEPTH +#endif + | GLUT_STENCIL); + glutInitWindowPosition( 0, 0 ); + glutInitWindowSize(400, 300 ); + glutCreateWindow(argv[0]); + glutReshapeFunc(reshape); + glutDisplayFunc(draw_scene); + glutKeyboardFunc(Key); + glutSpecialFunc(SpecialKey); + glutIdleFunc(idle); + + init(); + + glutMainLoop(); + return 0; +} |