From: Brian Paul Date: Sat, 15 Dec 2001 23:28:15 +0000 (+0000) Subject: warp a quadmesh with a gravitational source via vertex program X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c11120270cefa3656a46029934dc20c4d70ffcb6;p=mesa.git warp a quadmesh with a gravitational source via vertex program --- diff --git a/progs/tests/vpwarpmesh.c b/progs/tests/vpwarpmesh.c new file mode 100644 index 00000000000..166ef9c5027 --- /dev/null +++ b/progs/tests/vpwarpmesh.c @@ -0,0 +1,236 @@ +/* + * Warp a triangle mesh with a vertex program. + */ + +#include +#include +#include +#include +#include +#define GL_GLEXT_PROTOTYPES +#include + +static float Xrot = -60.0, Yrot = 0.0, Zrot = 0.0; +static GLboolean Anim = GL_TRUE; +static GLfloat Phi = 0.0; + + +static void Idle( void ) +{ + Phi += 0.01; + glutPostRedisplay(); +} + + +static void DrawMesh( int rows, int cols ) +{ + static const GLfloat colorA[3] = { 0, 1, 0 }; + static const GLfloat colorB[3] = { 0, 0, 1 }; + const float dx = 2.0 / (cols - 1); + const float dy = 2.0 / (rows - 1); + float x, y; + int i, j; + +#if 1 +#define COLOR3FV(c) glVertexAttrib3fvNV(3, c) +#define VERTEX2F(x, y) glVertexAttrib2fNV(0, x, y) +#else +#define COLOR3FV(c) glColor3fv(c) +#define VERTEX2F(x, y) glVertex2f(x, y) +#endif + + y = -1.0; + for (i = 0; i < rows - 1; i++) { + glBegin(GL_QUAD_STRIP); + x = -1.0; + for (j = 0; j < cols; j++) { + if ((i + j) & 1) + COLOR3FV(colorA); + else + COLOR3FV(colorB); + VERTEX2F(x, y); + VERTEX2F(x, y + dy); + x += dx; + } + glEnd(); + y += dy; + } +} + + +static void Display( void ) +{ + glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); + + glPushMatrix(); + glRotatef(Xrot, 1, 0, 0); + glRotatef(Yrot, 0, 1, 0); + glRotatef(Zrot, 0, 0, 1); + + /* Position the gravity source */ + { + GLfloat x, y, z, r = 0.5; + x = r * cos(Phi); + y = r * sin(Phi); + z = 1.0; + glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 30, x, y, z, 1); + glDisable(GL_VERTEX_PROGRAM_NV); + glBegin(GL_POINTS); + glColor3f(1,1,1); + glVertex3f(x, y, z); + glEnd(); + } + + glEnable(GL_VERTEX_PROGRAM_NV); + DrawMesh(8, 8); + glPopMatrix(); + + glutSwapBuffers(); +} + + +static void Reshape( int width, int height ) +{ + float ar = (float) width / (float) height; + glViewport( 0, 0, width, height ); + glMatrixMode( GL_PROJECTION ); + glLoadIdentity(); + glFrustum( -1.0 * ar, 1.0 * ar, -1.0, 1.0, 5.0, 25.0 ); + glMatrixMode( GL_MODELVIEW ); + glLoadIdentity(); + glTranslatef( 0.0, 0.0, -12.0 ); + glScalef(2, 2, 2); +} + + +static void Key( unsigned char key, int x, int y ) +{ + (void) x; + (void) y; + switch (key) { + case 'a': + Anim = !Anim; + if (Anim) + glutIdleFunc(Idle); + else + glutIdleFunc(NULL); + break; + case 'p': + Phi += 0.2; + break; + case 'z': + Zrot -= 5.0; + break; + case 'Z': + Zrot += 5.0; + break; + case 27: + exit(0); + break; + } + glutPostRedisplay(); +} + + +static void SpecialKey( int key, int x, int y ) +{ + const GLfloat step = 3.0; + (void) x; + (void) y; + switch (key) { + case GLUT_KEY_UP: + Xrot -= step; + break; + case GLUT_KEY_DOWN: + Xrot += step; + break; + case GLUT_KEY_LEFT: + Yrot -= step; + break; + case GLUT_KEY_RIGHT: + Yrot += step; + break; + } + glutPostRedisplay(); +} + + +static void Init( void ) +{ + /* + * c[0..3] = modelview matrix + * c[4..7] = inverse modelview matrix + * c[30] = gravity source location + * c[31] = gravity source strength + * c[32] = light pos + * c[35] = diffuse color + */ + static const char prog[] = + "!!VP1.0\n" + + "# Compute distance from vertex to gravity source\n" + "ADD R1, c[30], -v[OPOS]; # vector from vertex to gravity\n" + "DP3 R2, R1, R1; # dot product\n" + "RSQ R2, R2.x; # square root = distance\n" + "MUL R2, R2, c[31].xxxx; # scale by the gravity factor\n" + + "# Displace vertex by gravity factor along R1 vector\n" + "MAD R3, R1, R2, v[OPOS];\n" + + "# Continue with typical modelview/projection\n" + "DP4 o[HPOS].x, c[0], R3 ; # object x MVP -> clip\n" + "DP4 o[HPOS].y, c[1], R3 ;\n" + "DP4 o[HPOS].z, c[2], R3 ;\n" + "DP4 o[HPOS].w, c[3], R3 ;\n" + + "MOV o[COL0], v[COL0];\n # copy input color to output color\n" + + "END"; + + if (!glutExtensionSupported("GL_NV_vertex_program")) { + printf("Sorry, this program requires GL_NV_vertex_program"); + exit(1); + } + + glLoadProgramNV(GL_VERTEX_PROGRAM_NV, 1, + strlen(prog), (const GLubyte *) prog); + assert(glIsProgramNV(1)); + glBindProgramNV(GL_VERTEX_PROGRAM_NV, 1); + + /* Load the program registers */ + glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 0, GL_MODELVIEW_PROJECTION_NV, GL_IDENTITY_NV); + glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 4, GL_MODELVIEW, GL_INVERSE_TRANSPOSE_NV); + + /* Light position */ + glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 32, 2, 2, 4, 1); + /* Diffuse material color */ + glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 35, 0.25, 0, 0.25, 1); + + /* Gravity strength */ + glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 31, .5, 0, 0, 0); + + glEnable(GL_DEPTH_TEST); + glClearColor(0.3, 0.3, 0.3, 1); + glShadeModel(GL_FLAT); + glPointSize(3); + printf("glGetError = %d\n", (int) glGetError()); +} + + +int main( int argc, char *argv[] ) +{ + glutInit( &argc, argv ); + glutInitWindowPosition( 0, 0 ); + glutInitWindowSize( 250, 250 ); + glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH ); + glutCreateWindow(argv[0]); + glutReshapeFunc( Reshape ); + glutKeyboardFunc( Key ); + glutSpecialFunc( SpecialKey ); + glutDisplayFunc( Display ); + if (Anim) + glutIdleFunc(Idle); + Init(); + glutMainLoop(); + return 0; +}