From 4cef881e1f7691b4d0b3704f868713b22fb456ae Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Mon, 7 Apr 2003 23:05:50 +0000 Subject: Demo of per-pixel lighting with a fragment program. --- progs/demos/fplight.c | 279 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 279 insertions(+) create mode 100644 progs/demos/fplight.c (limited to 'progs/demos/fplight.c') diff --git a/progs/demos/fplight.c b/progs/demos/fplight.c new file mode 100644 index 0000000000..12a3e917ac --- /dev/null +++ b/progs/demos/fplight.c @@ -0,0 +1,279 @@ +/* + * Use GL_NV_fragment_program to implement per-pixel lighting. + * + * Brian Paul + * 7 April 2003 + */ + +#include +#include +#include +#include +#include +#define GL_GLEXT_PROTOTYPES +#include + + +static GLfloat Diffuse[4] = { 0.5, 0.5, 1.0, 1.0 }; +static GLfloat Specular[4] = { 0.8, 0.8, 0.8, 1.0 }; +static GLfloat LightPos[4] = { 0.0, 10.0, 20.0, 1.0 }; +static GLfloat Delta = 1.0; + +static GLuint FragProg; +static GLuint VertProg; +static GLboolean Anim = GL_TRUE; +static GLboolean Wire = GL_FALSE; +static GLboolean PixelLight = GL_TRUE; + +static GLfloat Xrot = 0, Yrot = 0; + + +#define NAMED_PARAMETER4FV(prog, name, v) \ + glProgramNamedParameter4fvNV(prog, strlen(name), (const GLubyte *) name, v) + + +static void Display( void ) +{ + glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); + + if (PixelLight) { + NAMED_PARAMETER4FV(FragProg, "LightPos", LightPos); + glEnable(GL_FRAGMENT_PROGRAM_NV); + glEnable(GL_VERTEX_PROGRAM_NV); + glDisable(GL_LIGHTING); + } + else { + glLightfv(GL_LIGHT0, GL_POSITION, LightPos); + glDisable(GL_FRAGMENT_PROGRAM_NV); + glDisable(GL_VERTEX_PROGRAM_NV); + glEnable(GL_LIGHTING); + } + + glPushMatrix(); + glRotatef(Xrot, 1, 0, 0); + glRotatef(Yrot, 0, 1, 0); + + glTexCoord2f(0, 0); +#if 1 + glutSolidSphere(2.0, 10, 5); +#else + { + GLUquadricObj *q = gluNewQuadric(); + gluQuadricNormals(q, GL_SMOOTH); + gluQuadricTexture(q, GL_TRUE); + glRotatef(90, 1, 0, 0); + glTranslatef(0, 0, -1); + gluCylinder(q, 1.0, 1.0, 2.0, 24, 1); + gluDeleteQuadric(q); + } +#endif + + glPopMatrix(); + + glutSwapBuffers(); +} + + +static void Idle(void) +{ + LightPos[0] += Delta; + if (LightPos[0] > 25.0) + Delta = -1.0; + else if (LightPos[0] <- 25.0) + Delta = 1.0; + glutPostRedisplay(); +} + + +static void Reshape( int width, int height ) +{ + glViewport( 0, 0, width, height ); + glMatrixMode( GL_PROJECTION ); + glLoadIdentity(); + glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 ); + /*glOrtho( -2.0, 2.0, -2.0, 2.0, 5.0, 25.0 );*/ + glMatrixMode( GL_MODELVIEW ); + glLoadIdentity(); + glTranslatef( 0.0, 0.0, -15.0 ); +} + + +static void Key( unsigned char key, int x, int y ) +{ + (void) x; + (void) y; + switch (key) { + case ' ': + Anim = !Anim; + if (Anim) + glutIdleFunc(Idle); + else + glutIdleFunc(NULL); + break; + case 'x': + LightPos[0] -= 1.0; + break; + case 'X': + LightPos[0] += 1.0; + break; + case 'w': + Wire = !Wire; + if (Wire) + glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); + else + glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); + break; + case 'p': + PixelLight = !PixelLight; + if (PixelLight) { + printf("Per-pixel lighting\n"); + } + else { + printf("Conventional lighting\n"); + } + 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 ) +{ + static const char *fragProgramText = + "!!FP1.0\n" + "DECLARE Diffuse; \n" + "DECLARE Specular; \n" + "DECLARE LightPos; \n" + + "# Compute normalized LightPos, put it in R0\n" + "DP3 R0.x, LightPos, LightPos;\n" + "RSQ R0.y, R0.x;\n" + "MUL R0, LightPos, R0.y;\n" + + "# Compute normalized normal, put it in R1\n" + "DP3 R1, f[TEX0], f[TEX0]; \n" + "RSQ R1.y, R1.x;\n" + "MUL R1, f[TEX0], R1.y;\n" + + "# Compute dot product of light direction and normal vector\n" + "DP3 R2, R0, R1;" + + "MUL R3, Diffuse, R2; # diffuse attenuation\n" + + "POW R4, R2.x, {20.0}.x; # specular exponent\n" + + "MUL R5, Specular, R4; # specular attenuation\n" + + "ADD o[COLR], R3, R5; # add diffuse and specular colors\n" + "END \n" + ; + + static const char *vertProgramText = + "!!VP1.0\n" + "# typical modelview/projection transform\n" + "DP4 o[HPOS].x, c[0], v[OPOS] ;\n" + "DP4 o[HPOS].y, c[1], v[OPOS] ;\n" + "DP4 o[HPOS].z, c[2], v[OPOS] ;\n" + "DP4 o[HPOS].w, c[3], v[OPOS] ;\n" + "# transform normal by inv transpose of modelview, put in tex0\n" + "DP4 o[TEX0].x, c[4], v[NRML] ;\n" + "DP4 o[TEX0].y, c[5], v[NRML] ;\n" + "DP4 o[TEX0].z, c[6], v[NRML] ;\n" + "DP4 o[TEX0].w, c[7], v[NRML] ;\n" + "END\n"; + ; + + if (!glutExtensionSupported("GL_NV_vertex_program")) { + printf("Sorry, this demo requires GL_NV_vertex_program\n"); + exit(1); + } + if (!glutExtensionSupported("GL_NV_fragment_program")) { + printf("Sorry, this demo requires GL_NV_fragment_program\n"); + exit(1); + } + + glGenProgramsNV(1, &FragProg); + glGenProgramsNV(1, &VertProg); + + /* + * Fragment program + */ + glLoadProgramNV(GL_FRAGMENT_PROGRAM_NV, FragProg, + strlen(fragProgramText), + (const GLubyte *) fragProgramText); + assert(glIsProgramNV(FragProg)); + glBindProgramNV(GL_FRAGMENT_PROGRAM_NV, FragProg); + + NAMED_PARAMETER4FV(FragProg, "Diffuse", Diffuse); + NAMED_PARAMETER4FV(FragProg, "Specular", Specular); + + /* + * Vertex program + */ + glLoadProgramNV(GL_VERTEX_PROGRAM_NV, VertProg, + strlen(vertProgramText), + (const GLubyte *) vertProgramText); + assert(glIsProgramNV(VertProg)); + glBindProgramNV(GL_VERTEX_PROGRAM_NV, VertProg); + 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); + + /* + * Misc init + */ + glClearColor(0.3, 0.3, 0.3, 0.0); + glEnable(GL_ALPHA_TEST); /* temporary hack */ + glEnable(GL_DEPTH_TEST); + glEnable(GL_LIGHT0); + glEnable(GL_LIGHTING); + glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, Diffuse); + glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, Specular); + glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 20.0); + + printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); + printf("Press p to toggle between per-pixel and per-vertex lighting\n"); +} + + +int main( int argc, char *argv[] ) +{ + glutInit( &argc, argv ); + glutInitWindowPosition( 0, 0 ); + glutInitWindowSize( 200, 200 ); + 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; +} -- cgit v1.2.3