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authorBrian Paul <brian.paul@tungstengraphics.com>2001-12-15 23:28:15 +0000
committerBrian Paul <brian.paul@tungstengraphics.com>2001-12-15 23:28:15 +0000
commitc11120270cefa3656a46029934dc20c4d70ffcb6 (patch)
treea6eb5db8e872fce36ef01abcc19eed2738ab6db2
parent9cb3947c56f7415b9172f3cdd27ea82cbcc762a6 (diff)
warp a quadmesh with a gravitational source via vertex program
-rw-r--r--progs/tests/vpwarpmesh.c236
1 files changed, 236 insertions, 0 deletions
diff --git a/progs/tests/vpwarpmesh.c b/progs/tests/vpwarpmesh.c
new file mode 100644
index 0000000000..166ef9c502
--- /dev/null
+++ b/progs/tests/vpwarpmesh.c
@@ -0,0 +1,236 @@
+/*
+ * Warp a triangle mesh with a vertex program.
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#define GL_GLEXT_PROTOTYPES
+#include <GL/glut.h>
+
+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;
+}