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Diffstat (limited to 'nx-X11/extras/Mesa_6.4.1/progs/demos/tessdemo.c')
| -rw-r--r-- | nx-X11/extras/Mesa_6.4.1/progs/demos/tessdemo.c | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/nx-X11/extras/Mesa_6.4.1/progs/demos/tessdemo.c b/nx-X11/extras/Mesa_6.4.1/progs/demos/tessdemo.c new file mode 100644 index 000000000..26403eee0 --- /dev/null +++ b/nx-X11/extras/Mesa_6.4.1/progs/demos/tessdemo.c @@ -0,0 +1,524 @@ + +/* + * A demo of the GLU polygon tesselation functions written by Bogdan Sikorski. + * Updated for GLU 1.3 tessellation by Gareth Hughes <gareth@valinux.com> + */ + +#include <GL/glut.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#define MAX_POINTS 256 +#define MAX_CONTOURS 32 +#define MAX_TRIANGLES 256 + +#ifndef GLCALLBACK +#ifdef CALLBACK +#define GLCALLBACK CALLBACK +#else +#define GLCALLBACK +#endif +#endif + +#ifdef GLU_VERSION_1_2 + +typedef enum{ QUIT, TESSELATE, CLEAR } menu_entries; +typedef enum{ DEFINE, TESSELATED } mode_type; + +static GLsizei width, height; +static GLuint contour_cnt; +static GLuint triangle_cnt; + +static mode_type mode; +static int menu; + +static GLuint list_start; + +static GLfloat edge_color[3]; + +static struct { + GLfloat p[MAX_POINTS][2]; + GLuint point_cnt; +} contours[MAX_CONTOURS]; + +static struct { + GLsizei no; + GLfloat p[3][2]; + GLclampf color[3][3]; +} triangles[MAX_TRIANGLES]; + + + +static void GLCALLBACK error_callback( GLenum err ) +{ + int len, i; + char const *str; + + glColor3f( 0.9, 0.9, 0.9 ); + glRasterPos2i( 5, 5 ); + + str = (const char *) gluErrorString( err ); + len = strlen( str ); + + for ( i = 0 ; i < len ; i++ ) { + glutBitmapCharacter( GLUT_BITMAP_9_BY_15, str[i] ); + } +} + +static void GLCALLBACK begin_callback( GLenum mode ) +{ + /* Allow multiple triangles to be output inside the begin/end pair. */ + triangle_cnt = 0; + triangles[triangle_cnt].no = 0; +} + +static void GLCALLBACK edge_callback( GLenum flag ) +{ + /* Persist the edge flag across triangles. */ + if ( flag == GL_TRUE ) { + edge_color[0] = 1.0; + edge_color[1] = 1.0; + edge_color[2] = 0.5; + } else { + edge_color[0] = 1.0; + edge_color[1] = 0.0; + edge_color[2] = 0.0; + } +} + +static void GLCALLBACK end_callback() +{ + GLuint i; + + glBegin( GL_LINES ); + + /* Output the three edges of each triangle as lines colored + according to their edge flag. */ + for ( i = 0 ; i < triangle_cnt ; i++ ) { + glColor3f( triangles[i].color[0][0], + triangles[i].color[0][1], + triangles[i].color[0][2] ); + + glVertex2f( triangles[i].p[0][0], triangles[i].p[0][1] ); + glVertex2f( triangles[i].p[1][0], triangles[i].p[1][1] ); + + glColor3f( triangles[i].color[1][0], + triangles[i].color[1][1], + triangles[i].color[1][2] ); + + glVertex2f( triangles[i].p[1][0], triangles[i].p[1][1] ); + glVertex2f( triangles[i].p[2][0], triangles[i].p[2][1] ); + + glColor3f( triangles[i].color[2][0], + triangles[i].color[2][1], + triangles[i].color[2][2] ); + + glVertex2f( triangles[i].p[2][0], triangles[i].p[2][1] ); + glVertex2f( triangles[i].p[0][0], triangles[i].p[0][1] ); + } + + glEnd(); +} + +static void GLCALLBACK vertex_callback( void *data ) +{ + GLsizei no; + GLfloat *p; + + p = (GLfloat *) data; + no = triangles[triangle_cnt].no; + + triangles[triangle_cnt].p[no][0] = p[0]; + triangles[triangle_cnt].p[no][1] = p[1]; + + triangles[triangle_cnt].color[no][0] = edge_color[0]; + triangles[triangle_cnt].color[no][1] = edge_color[1]; + triangles[triangle_cnt].color[no][2] = edge_color[2]; + + /* After every three vertices, initialize the next triangle. */ + if ( ++(triangles[triangle_cnt].no) == 3 ) { + triangle_cnt++; + triangles[triangle_cnt].no = 0; + } +} + +static void GLCALLBACK combine_callback( GLdouble coords[3], + GLdouble *vertex_data[4], + GLfloat weight[4], void **data ) +{ + GLfloat *vertex; + + vertex = (GLfloat *) malloc( 2 * sizeof(GLfloat) ); + + vertex[0] = (GLfloat) coords[0]; + vertex[1] = (GLfloat) coords[1]; + + *data = vertex; +} + + +static void set_screen_wh( GLsizei w, GLsizei h ) +{ + width = w; + height = h; +} + +typedef void (GLAPIENTRY *callback_t)(); + +static void tesse( void ) +{ + GLUtesselator *tobj; + GLdouble data[3]; + GLuint i, j, point_cnt; + + list_start = glGenLists( 2 ); + + tobj = gluNewTess(); + + if ( tobj != NULL ) { + gluTessNormal( tobj, 0.0, 0.0, 1.0 ); + gluTessCallback( tobj, GLU_TESS_BEGIN, (callback_t) glBegin ); + gluTessCallback( tobj, GLU_TESS_VERTEX, (callback_t) glVertex2fv ); + gluTessCallback( tobj, GLU_TESS_END, (callback_t) glEnd ); + gluTessCallback( tobj, GLU_TESS_ERROR, (callback_t) error_callback ); + gluTessCallback( tobj, GLU_TESS_COMBINE, (callback_t) combine_callback ); + + glNewList( list_start, GL_COMPILE ); + gluBeginPolygon( tobj ); + + for ( j = 0 ; j <= contour_cnt ; j++ ) { + point_cnt = contours[j].point_cnt; + gluNextContour( tobj, GLU_UNKNOWN ); + + for ( i = 0 ; i < point_cnt ; i++ ) { + data[0] = (GLdouble)( contours[j].p[i][0] ); + data[1] = (GLdouble)( contours[j].p[i][1] ); + data[2] = 0.0; + gluTessVertex( tobj, data, contours[j].p[i] ); + } + } + + gluEndPolygon( tobj ); + glEndList(); + + gluTessCallback( tobj, GLU_TESS_BEGIN, (callback_t) begin_callback ); + gluTessCallback( tobj, GLU_TESS_VERTEX, (callback_t) vertex_callback ); + gluTessCallback( tobj, GLU_TESS_END, (callback_t) end_callback ); + gluTessCallback( tobj, GLU_TESS_EDGE_FLAG, (callback_t) edge_callback ); + + glNewList( list_start + 1, GL_COMPILE ); + gluBeginPolygon( tobj ); + + for ( j = 0 ; j <= contour_cnt ; j++ ) { + point_cnt = contours[j].point_cnt; + gluNextContour( tobj, GLU_UNKNOWN ); + + for ( i = 0 ; i < point_cnt ; i++ ) { + data[0] = (GLdouble)( contours[j].p[i][0] ); + data[1] = (GLdouble)( contours[j].p[i][1] ); + data[2] = 0.0; + gluTessVertex( tobj, data, contours[j].p[i] ); + } + } + + gluEndPolygon( tobj ); + glEndList(); + + gluDeleteTess( tobj ); + + glutMouseFunc( NULL ); + mode = TESSELATED; + } +} + +static void left_down( int x1, int y1 ) +{ + GLfloat P[2]; + GLuint point_cnt; + + /* translate GLUT into GL coordinates */ + + P[0] = x1; + P[1] = height - y1; + + point_cnt = contours[contour_cnt].point_cnt; + + contours[contour_cnt].p[point_cnt][0] = P[0]; + contours[contour_cnt].p[point_cnt][1] = P[1]; + + glBegin( GL_LINES ); + + if ( point_cnt ) { + glVertex2fv( contours[contour_cnt].p[point_cnt-1] ); + glVertex2fv( P ); + } else { + glVertex2fv( P ); + glVertex2fv( P ); + } + + glEnd(); + glFinish(); + + contours[contour_cnt].point_cnt++; +} + +static void middle_down( int x1, int y1 ) +{ + GLuint point_cnt; + (void) x1; + (void) y1; + + point_cnt = contours[contour_cnt].point_cnt; + + if ( point_cnt > 2 ) { + glBegin( GL_LINES ); + + glVertex2fv( contours[contour_cnt].p[0] ); + glVertex2fv( contours[contour_cnt].p[point_cnt-1] ); + + contours[contour_cnt].p[point_cnt][0] = -1; + + glEnd(); + glFinish(); + + contour_cnt++; + contours[contour_cnt].point_cnt = 0; + } +} + +static void mouse_clicked( int button, int state, int x, int y ) +{ + x -= x%10; + y -= y%10; + + switch ( button ) { + case GLUT_LEFT_BUTTON: + if ( state == GLUT_DOWN ) { + left_down( x, y ); + } + break; + case GLUT_MIDDLE_BUTTON: + if ( state == GLUT_DOWN ) { + middle_down( x, y ); + } + break; + } +} + +static void display( void ) +{ + GLuint i,j; + GLsizei ii, jj; + GLuint point_cnt; + + glClear( GL_COLOR_BUFFER_BIT ); + + switch ( mode ) { + case DEFINE: + /* draw grid */ + glColor3f( 0.6, 0.5, 0.5 ); + + glBegin( GL_LINES ); + + for ( ii = 0 ; ii < width ; ii += 10 ) { + for ( jj = 0 ; jj < height ; jj += 10 ) { + glVertex2i( 0, jj ); + glVertex2i( width, jj ); + glVertex2i( ii, height ); + glVertex2i( ii, 0 ); + } + } + + glEnd(); + + glColor3f( 1.0, 1.0, 0.0 ); + + for ( i = 0 ; i <= contour_cnt ; i++ ) { + point_cnt = contours[i].point_cnt; + + glBegin( GL_LINES ); + + switch ( point_cnt ) { + case 0: + break; + case 1: + glVertex2fv( contours[i].p[0] ); + glVertex2fv( contours[i].p[0] ); + break; + case 2: + glVertex2fv( contours[i].p[0] ); + glVertex2fv( contours[i].p[1] ); + break; + default: + --point_cnt; + for ( j = 0 ; j < point_cnt ; j++ ) { + glVertex2fv( contours[i].p[j] ); + glVertex2fv( contours[i].p[j+1] ); + } + if ( contours[i].p[j+1][0] == -1 ) { + glVertex2fv( contours[i].p[0] ); + glVertex2fv( contours[i].p[j] ); + } + break; + } + + glEnd(); + } + + glFinish(); + break; + + case TESSELATED: + /* draw triangles */ + glColor3f( 0.7, 0.7, 0.0 ); + glCallList( list_start ); + + glLineWidth( 2.0 ); + glCallList( list_start + 1 ); + glLineWidth( 1.0 ); + + glFlush(); + break; + } + + glColor3f( 1.0, 1.0, 0.0 ); +} + +static void clear( void ) +{ + contour_cnt = 0; + contours[0].point_cnt = 0; + triangle_cnt = 0; + + glutMouseFunc( mouse_clicked ); + + mode = DEFINE; + + glDeleteLists( list_start, 2 ); + list_start = 0; +} + +static void quit( void ) +{ + exit( 0 ); +} + +static void menu_selected( int entry ) +{ + switch ( entry ) { + case CLEAR: + clear(); + break; + case TESSELATE: + tesse(); + break; + case QUIT: + quit(); + break; + } + + glutPostRedisplay(); +} + +static void key_pressed( unsigned char key, int x, int y ) +{ + (void) x; + (void) y; + + switch ( key ) { + case 'c': + case 'C': + clear(); + break; + case 't': + case 'T': + tesse(); + break; + case 27: + case 'q': + case 'Q': + quit(); + break; + } + + glutPostRedisplay(); +} + +static void myinit( void ) +{ + /* clear background to gray */ + glClearColor( 0.4, 0.4, 0.4, 0.0 ); + glShadeModel( GL_FLAT ); + glPolygonMode( GL_FRONT, GL_FILL ); + + menu = glutCreateMenu( menu_selected ); + + glutAddMenuEntry( "clear", CLEAR ); + glutAddMenuEntry( "tesselate", TESSELATE ); + glutAddMenuEntry( "quit", QUIT ); + + glutAttachMenu( GLUT_RIGHT_BUTTON ); + + glutMouseFunc( mouse_clicked ); + glutKeyboardFunc( key_pressed ); + + contour_cnt = 0; + mode = DEFINE; +} + +static void reshape( GLsizei w, GLsizei h ) +{ + glViewport( 0, 0, w, h ); + + glMatrixMode( GL_PROJECTION ); + glLoadIdentity(); + glOrtho( 0.0, (GLdouble)w, 0.0, (GLdouble)h, -1.0, 1.0 ); + + glMatrixMode( GL_MODELVIEW ); + glLoadIdentity(); + + set_screen_wh( w, h ); +} + +#endif + + +static void usage( void ) +{ + printf( "Use left mouse button to place vertices.\n" ); + printf( "Press middle mouse button when done.\n" ); + printf( "Select tesselate from the pop-up menu.\n" ); +} + + +int main( int argc, char **argv ) +{ + const char *version = (const char *) gluGetString( GLU_VERSION ); + printf( "GLU version string: %s\n", version ); + if ( strstr( version, "1.0" ) || strstr( version, "1.1" ) ) { + fprintf( stderr, "Sorry, this demo reqiures GLU 1.2 or later.\n" ); + exit( 1 ); + } + + usage(); + + glutInit( &argc, argv ); + glutInitDisplayMode( GLUT_SINGLE | GLUT_RGB ); + glutInitWindowPosition(0, 0); + glutInitWindowSize( 400, 400 ); + glutCreateWindow( argv[0] ); + + /* GH: Bit of a hack... + */ +#ifdef GLU_VERSION_1_2 + myinit(); + + glutDisplayFunc( display ); + glutReshapeFunc( reshape ); + + glutMainLoop(); +#endif + + return 0; +} |