/* 10_fragment_lighting.c - OpenGL-based per-fragment lighting example
using Cg program from Chapter 5 of "The Cg Tutorial" (Addison-Wesley,
ISBN 0321194969). */
/* Requires the OpenGL Utility Toolkit (GLUT) and Cg runtime (version
1.5 or higher). */
#include <stdio.h> /* for printf and NULL */
#include <stdlib.h> /* for exit */
#include <math.h> /* for sqrt, sin, cos, and fabs */
#include <assert.h> /* for assert */
#include <GL/glew.h>
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
#ifdef _WIN32
#include <GL/wglew.h>
#else
#ifdef __APPLE__
#include <OpenGL/OpenGL.h>
#else
#include <GL/glxew.h>
#endif
#endif
#include <Cg/cg.h> /* Can't include this? Is Cg Toolkit installed! */
#include <Cg/cgGL.h>
static CGcontext myCgContext;
static CGprofile myCgVertexProfile,
myCgFragmentProfile;
static CGprogram myCgVertexProgram,
myCgFragmentProgram;
static CGparameter myCgVertexParam_modelViewProj,
myCgFragmentParam_globalAmbient,
myCgFragmentParam_lightColor,
myCgFragmentParam_lightPosition,
myCgFragmentParam_eyePosition,
myCgFragmentParam_Ke,
myCgFragmentParam_Ka,
myCgFragmentParam_Kd,
myCgFragmentParam_Ks,
myCgFragmentParam_shininess;
static const char *myProgramName = "10_fragment_lighting",
*myVertexProgramFileName = "C5E2v_fragmentLighting.cg",
/* Page 124 */ *myVertexProgramName = "C5E2v_fragmentLighting",
*myFragmentProgramFileName = "C5E3f_basicLight.cg",
/* Page 125 */ *myFragmentProgramName = "C5E3f_basicLight";
static float myLightAngle = -0.4; /* Angle light rotates around scene. */
static float myProjectionMatrix[16];
static float myGlobalAmbient[3] = { 0.1, 0.1, 0.1 }; /* Dim */
static float myLightColor[3] = { 0.95, 0.95, 0.95 }; /* White */
static void checkForCgError(const char *situation)
{
CGerror error;
const char *string = cgGetLastErrorString(&error);
if (error != CG_NO_ERROR) {
printf("%s: %s: %s\n",
myProgramName, situation, string);
if (error == CG_COMPILER_ERROR) {
printf("%s\n", cgGetLastListing(myCgContext));
}
exit(1);
}
}
/* Forward declared GLUT callbacks registered by main. */
static void reshape(int width, int height);
static void display(void);
static void keyboard(unsigned char c, int x, int y);
static void menu(int item);
static void requestSynchronizedSwapBuffers(void);
int main(int argc, char **argv)
{
glutInitWindowSize(400, 400);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_MULTISAMPLE);
glutInit(&argc, argv);
glutCreateWindow(myProgramName);
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutReshapeFunc(reshape);
/* Initialize OpenGL entry points. */
if (glewInit()!=GLEW_OK || !GLEW_VERSION_1_1) {
fprintf(stderr, "%s: failed to initialize GLEW, OpenGL 1.1 required.\n", myProgramName);
exit(1);
}
requestSynchronizedSwapBuffers();
glClearColor(0.1, 0.1, 0.1, 0); /* Gray background. */
glEnable(GL_DEPTH_TEST); /* Hidden surface removal. */
myCgContext = cgCreateContext();
checkForCgError("creating context");
cgGLSetDebugMode(CG_FALSE);
cgSetParameterSettingMode(myCgContext, CG_DEFERRED_PARAMETER_SETTING);
myCgVertexProfile = cgGLGetLatestProfile(CG_GL_VERTEX);
cgGLSetOptimalOptions(myCgVertexProfile);
checkForCgError("selecting vertex profile");
myCgVertexProgram =
cgCreateProgramFromFile(
myCgContext, /* Cg runtime context */
CG_SOURCE, /* Program in human-readable form */
myVertexProgramFileName, /* Name of file containing program */
myCgVertexProfile, /* Profile: OpenGL ARB vertex program */
myVertexProgramName, /* Entry function name */
NULL); /* No extra compiler options */
checkForCgError("creating vertex program from file");
cgGLLoadProgram(myCgVertexProgram);
checkForCgError("loading vertex program");
#define GET_VERTEX_PARAM(name) \
myCgVertexParam_##name = \
cgGetNamedParameter(myCgVertexProgram, #name); \
checkForCgError("could not get " #name " parameter");
GET_VERTEX_PARAM(modelViewProj);
myCgFragmentProfile = cgGLGetLatestProfile(CG_GL_FRAGMENT);
cgGLSetOptimalOptions(myCgFragmentProfile);
checkForCgError("selecting fragment profile");
myCgFragmentProgram =
cgCreateProgramFromFile(
myCgContext, /* Cg runtime context */
CG_SOURCE, /* Program in human-readable form */
myFragmentProgramFileName,
myCgFragmentProfile, /* Profile: latest fragment profile */
myFragmentProgramName, /* Entry function name */
NULL); /* No extra compiler options */
checkForCgError("creating fragment program from string");
cgGLLoadProgram(myCgFragmentProgram);
checkForCgError("loading fragment program");
#define GET_FRAGMENT_PARAM(name) \
myCgFragmentParam_##name = \
cgGetNamedParameter(myCgFragmentProgram, #name); \
checkForCgError("could not get " #name " parameter");
GET_FRAGMENT_PARAM(globalAmbient);
GET_FRAGMENT_PARAM(lightColor);
GET_FRAGMENT_PARAM(lightPosition);
GET_FRAGMENT_PARAM(eyePosition);
GET_FRAGMENT_PARAM(Ke);
GET_FRAGMENT_PARAM(Ka);
GET_FRAGMENT_PARAM(Kd);
GET_FRAGMENT_PARAM(Ks);
GET_FRAGMENT_PARAM(shininess);
/* Set light source color parameters once. */
cgSetParameter3fv(myCgFragmentParam_globalAmbient, myGlobalAmbient);
cgSetParameter3fv(myCgFragmentParam_lightColor, myLightColor);
glutCreateMenu(menu);
glutAddMenuEntry("[ ] Animate", ' ');
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutMainLoop();
return 0;
}
/* Forward declared routine used by reshape callback. */
static void buildPerspectiveMatrix(double fieldOfView,
double aspectRatio,
double zMin, double zMax,
float m[16]);
static void reshape(int width, int height)
{
double aspectRatio = (float) width / (float) height;
double fieldOfView = 40.0; /* Degrees */
/* Build projection matrix once. */
buildPerspectiveMatrix(fieldOfView, aspectRatio,
1.0, 20.0, /* Znear and Zfar */
myProjectionMatrix);
glViewport(0, 0, width, height);
}
static const double myPi = 3.14159265358979323846;
/* Build a row-major (C-style) 4x4 matrix transform based on the
parameters for gluPerspective. */
static void buildPerspectiveMatrix(double fieldOfView,
double aspectRatio,
double zNear, double zFar,
float m[16])
{
double sine, cotangent, deltaZ;
double radians = fieldOfView / 2.0 * myPi / 180.0;
deltaZ = zFar - zNear;
sine = sin(radians);
/* Should be non-zero to avoid division by zero. */
assert(deltaZ);
assert(sine);
assert(aspectRatio);
cotangent = cos(radians) / sine;
m[0*4+0] = cotangent / aspectRatio;
m[0*4+1] = 0.0;
m[0*4+2] = 0.0;
m[0*4+3] = 0.0;
m[1*4+0] = 0.0;
m[1*4+1] = cotangent;
m[1*4+2] = 0.0;
m[1*4+3] = 0.0;
m[2*4+0] = 0.0;
m[2*4+1] = 0.0;
m[2*4+2] = -(zFar + zNear) / deltaZ;
m[2*4+3] = -2 * zNear * zFar / deltaZ;
m[3*4+0] = 0.0;
m[3*4+1] = 0.0;
m[3*4+2] = -1;
m[3*4+3] = 0;
}
/* Build a row-major (C-style) 4x4 matrix transform based on the
parameters for gluLookAt. */
static void buildLookAtMatrix(double eyex, double eyey, double eyez,
double centerx, double centery, double centerz,
double upx, double upy, double upz,
float m[16])
{
double x[3], y[3], z[3], mag;
/* Difference eye and center vectors to make Z vector. */
z[0] = eyex - centerx;
z[1] = eyey - centery;
z[2] = eyez - centerz;
/* Normalize Z. */
mag = sqrt(z[0]*z[0] + z[1]*z[1] + z[2]*z[2]);
if (mag) {
z[0] /= mag;
z[1] /= mag;
z[2] /= mag;
}
/* Up vector makes Y vector. */
y[0] = upx;
y[1] = upy;
y[2] = upz;
/* X vector = Y cross Z. */
x[0] = y[1]*z[2] - y[2]*z[1];
x[1] = -y[0]*z[2] + y[2]*z[0];
x[2] = y[0]*z[1] - y[1]*z[0];
/* Recompute Y = Z cross X. */
y[0] = z[1]*x[2] - z[2]*x[1];
y[1] = -z[0]*x[2] + z[2]*x[0];
y[2] = z[0]*x[1] - z[1]*x[0];
/* Normalize X. */
mag = sqrt(x[0]*x[0] + x[1]*x[1] + x[2]*x[2]);
if (mag) {
x[0] /= mag;
x[1] /= mag;
x[2] /= mag;
}
/* Normalize Y. */
mag = sqrt(y[0]*y[0] + y[1]*y[1] + y[2]*y[2]);
if (mag) {
y[0] /= mag;
y[1] /= mag;
y[2] /= mag;
}
/* Build resulting view matrix. */
m[0*4+0] = x[0]; m[0*4+1] = x[1];
m[0*4+2] = x[2]; m[0*4+3] = -x[0]*eyex + -x[1]*eyey + -x[2]*eyez;
m[1*4+0] = y[0]; m[1*4+1] = y[1];
m[1*4+2] = y[2]; m[1*4+3] = -y[0]*eyex + -y[1]*eyey + -y[2]*eyez;
m[2*4+0] = z[0]; m[2*4+1] = z[1];
m[2*4+2] = z[2]; m[2*4+3] = -z[0]*eyex + -z[1]*eyey + -z[2]*eyez;
m[3*4+0] = 0.0; m[3*4+1] = 0.0; m[3*4+2] = 0.0; m[3*4+3] = 1.0;
}
/* Build a row-major (C-style) 4x4 matrix transform based on the
parameters for glRotatef. */
static void makeRotateMatrix(float angle,
float ax, float ay, float az,
float m[16])
{
float radians, sine, cosine, ab, bc, ca, tx, ty, tz;
float axis[3];
float mag;
axis[0] = ax;
axis[1] = ay;
axis[2] = az;
mag = sqrt(axis[0]*axis[0] + axis[1]*axis[1] + axis[2]*axis[2]);
if (mag) {
axis[0] /= mag;
axis[1] /= mag;
axis[2] /= mag;
}
radians = angle * myPi / 180.0;
sine = sin(radians);
cosine = cos(radians);
ab = axis[0] * axis[1] * (1 - cosine);
bc = axis[1] * axis[2] * (1 - cosine);
ca = axis[2] * axis[0] * (1 - cosine);
tx = axis[0] * axis[0];
ty = axis[1] * axis[1];
tz = axis[2] * axis[2];
m[0] = tx + cosine * (1 - tx);
m[1] = ab + axis[2] * sine;
m[2] = ca - axis[1] * sine;
m[3] = 0.0f;
m[4] = ab - axis[2] * sine;
m[5] = ty + cosine * (1 - ty);
m[6] = bc + axis[0] * sine;
m[7] = 0.0f;
m[8] = ca + axis[1] * sine;
m[9] = bc - axis[0] * sine;
m[10] = tz + cosine * (1 - tz);
m[11] = 0;
m[12] = 0;
m[13] = 0;
m[14] = 0;
m[15] = 1;
}
/* Build a row-major (C-style) 4x4 matrix transform based on the
parameters for glTranslatef. */
static void makeTranslateMatrix(float x, float y, float z, float m[16])
{
m[0] = 1; m[1] = 0; m[2] = 0; m[3] = x;
m[4] = 0; m[5] = 1; m[6] = 0; m[7] = y;
m[8] = 0; m[9] = 0; m[10] = 1; m[11] = z;
m[12] = 0; m[13] = 0; m[14] = 0; m[15] = 1;
}
/* Simple 4x4 matrix by 4x4 matrix multiply. */
static void multMatrix(float dst[16],
const float src1[16], const float src2[16])
{
float tmp[16];
int i, j;
for (i=0; i<4; i++) {
for (j=0; j<4; j++) {
tmp[i*4+j] = src1[i*4+0] * src2[0*4+j] +
src1[i*4+1] * src2[1*4+j] +
src1[i*4+2] * src2[2*4+j] +
src1[i*4+3] * src2[3*4+j];
}
}
/* Copy result to dst (so dst can also be src1 or src2). */
for (i=0; i<16; i++)
dst[i] = tmp[i];
}
/* Invert a row-major (C-style) 4x4 matrix. */
static void invertMatrix(float *out, const float *m)
{
/* Assumes matrices are ROW major. */
#define SWAP_ROWS(a, b) { GLdouble *_tmp = a; (a)=(b); (b)=_tmp; }
#define MAT(m,r,c) (m)[(r)*4+(c)]
double wtmp[4][8];
double m0, m1, m2, m3, s;
double *r0, *r1, *r2, *r3;
r0 = wtmp[0], r1 = wtmp[1], r2 = wtmp[2], r3 = wtmp[3];
r0[0] = MAT(m,0,0), r0[1] = MAT(m,0,1),
r0[2] = MAT(m,0,2), r0[3] = MAT(m,0,3),
r0[4] = 1.0, r0[5] = r0[6] = r0[7] = 0.0,
r1[0] = MAT(m,1,0), r1[1] = MAT(m,1,1),
r1[2] = MAT(m,1,2), r1[3] = MAT(m,1,3),
r1[5] = 1.0, r1[4] = r1[6] = r1[7] = 0.0,
r2[0] = MAT(m,2,0), r2[1] = MAT(m,2,1),
r2[2] = MAT(m,2,2), r2[3] = MAT(m,2,3),
r2[6] = 1.0, r2[4] = r2[5] = r2[7] = 0.0,
r3[0] = MAT(m,3,0), r3[1] = MAT(m,3,1),
r3[2] = MAT(m,3,2), r3[3] = MAT(m,3,3),
r3[7] = 1.0, r3[4] = r3[5] = r3[6] = 0.0;
/* Choose myPivot, or die. */
if (fabs(r3[0])>fabs(r2[0])) SWAP_ROWS(r3, r2);
if (fabs(r2[0])>fabs(r1[0])) SWAP_ROWS(r2, r1);
if (fabs(r1[0])>fabs(r0[0])) SWAP_ROWS(r1, r0);
if (0.0 == r0[0]) {
assert(!"could not invert matrix");
}
/* Eliminate first variable. */
m1 = r1[0]/r0[0]; m2 = r2[0]/r0[0]; m3 = r3[0]/r0[0];
s = r0[1]; r1[1] -= m1 * s; r2[1] -= m2 * s; r3[1] -= m3 * s;
s = r0[2]; r1[2] -= m1 * s; r2[2] -= m2 * s; r3[2] -= m3 * s;
s = r0[3]; r1[3] -= m1 * s; r2[3] -= m2 * s; r3[3] -= m3 * s;
s = r0[4];
if (s != 0.0) { r1[4] -= m1 * s; r2[4] -= m2 * s; r3[4] -= m3 * s; }
s = r0[5];
if (s != 0.0) { r1[5] -= m1 * s; r2[5] -= m2 * s; r3[5] -= m3 * s; }
s = r0[6];
if (s != 0.0) { r1[6] -= m1 * s; r2[6] -= m2 * s; r3[6] -= m3 * s; }
s = r0[7];
if (s != 0.0) { r1[7] -= m1 * s; r2[7] -= m2 * s; r3[7] -= m3 * s; }
/* Choose myPivot, or die. */
if (fabs(r3[1])>fabs(r2[1])) SWAP_ROWS(r3, r2);
if (fabs(r2[1])>fabs(r1[1])) SWAP_ROWS(r2, r1);
if (0.0 == r1[1]) {
assert(!"could not invert matrix");
}
/* Eliminate second variable. */
m2 = r2[1]/r1[1]; m3 = r3[1]/r1[1];
r2[2] -= m2 * r1[2]; r3[2] -= m3 * r1[2];
r2[3] -= m2 * r1[3]; r3[3] -= m3 * r1[3];
s = r1[4]; if (0.0 != s) { r2[4] -= m2 * s; r3[4] -= m3 * s; }
s = r1[5]; if (0.0 != s) { r2[5] -= m2 * s; r3[5] -= m3 * s; }
s = r1[6]; if (0.0 != s) { r2[6] -= m2 * s; r3[6] -= m3 * s; }
s = r1[7]; if (0.0 != s) { r2[7] -= m2 * s; r3[7] -= m3 * s; }
/* Choose myPivot, or die. */
if (fabs(r3[2])>fabs(r2[2])) SWAP_ROWS(r3, r2);
if (0.0 == r2[2]) {
assert(!"could not invert matrix");
}
/* Eliminate third variable. */
m3 = r3[2]/r2[2];
r3[3] -= m3 * r2[3], r3[4] -= m3 * r2[4],
r3[5] -= m3 * r2[5], r3[6] -= m3 * r2[6],
r3[7] -= m3 * r2[7];
/* Last check. */
if (0.0 == r3[3]) {
assert(!"could not invert matrix");
}
s = 1.0/r3[3]; /* Now back substitute row 3. */
r3[4] *= s; r3[5] *= s; r3[6] *= s; r3[7] *= s;
m2 = r2[3]; /* Now back substitute row 2. */
s = 1.0/r2[2];
r2[4] = s * (r2[4] - r3[4] * m2), r2[5] = s * (r2[5] - r3[5] * m2),
r2[6] = s * (r2[6] - r3[6] * m2), r2[7] = s * (r2[7] - r3[7] * m2);
m1 = r1[3];
r1[4] -= r3[4] * m1, r1[5] -= r3[5] * m1,
r1[6] -= r3[6] * m1, r1[7] -= r3[7] * m1;
m0 = r0[3];
r0[4] -= r3[4] * m0, r0[5] -= r3[5] * m0,
r0[6] -= r3[6] * m0, r0[7] -= r3[7] * m0;
m1 = r1[2]; /* Now back substitute row 1. */
s = 1.0/r1[1];
r1[4] = s * (r1[4] - r2[4] * m1), r1[5] = s * (r1[5] - r2[5] * m1),
r1[6] = s * (r1[6] - r2[6] * m1), r1[7] = s * (r1[7] - r2[7] * m1);
m0 = r0[2];
r0[4] -= r2[4] * m0, r0[5] -= r2[5] * m0,
r0[6] -= r2[6] * m0, r0[7] -= r2[7] * m0;
m0 = r0[1]; /* Now back substitute row 0. */
s = 1.0/r0[0];
r0[4] = s * (r0[4] - r1[4] * m0), r0[5] = s * (r0[5] - r1[5] * m0),
r0[6] = s * (r0[6] - r1[6] * m0), r0[7] = s * (r0[7] - r1[7] * m0);
MAT(out,0,0) = r0[4]; MAT(out,0,1) = r0[5],
MAT(out,0,2) = r0[6]; MAT(out,0,3) = r0[7],
MAT(out,1,0) = r1[4]; MAT(out,1,1) = r1[5],
MAT(out,1,2) = r1[6]; MAT(out,1,3) = r1[7],
MAT(out,2,0) = r2[4]; MAT(out,2,1) = r2[5],
MAT(out,2,2) = r2[6]; MAT(out,2,3) = r2[7],
MAT(out,3,0) = r3[4]; MAT(out,3,1) = r3[5],
MAT(out,3,2) = r3[6]; MAT(out,3,3) = r3[7];
#undef MAT
#undef SWAP_ROWS
}
/* Simple 4x4 matrix by 4-component column vector multiply. */
static void transform(float dst[4],
const float mat[16], const float vec[4])
{
double tmp[4], invW;
int i;
for (i=0; i<4; i++) {
tmp[i] = mat[i*4+0] * vec[0] +
mat[i*4+1] * vec[1] +
mat[i*4+2] * vec[2] +
mat[i*4+3] * vec[3];
}
invW = 1 / tmp[3];
/* Apply perspective divide and copy to dst (so dst can vec). */
for (i=0; i<3; i++)
dst[i] = tmp[i] * tmp[3];
dst[3] = 1;
}
static void setBrassMaterial(void)
{
const float brassEmissive[3] = {0.0, 0.0, 0.0},
brassAmbient[3] = {0.33, 0.22, 0.03},
brassDiffuse[3] = {0.78, 0.57, 0.11},
brassSpecular[3] = {0.99, 0.91, 0.81},
brassShininess = 27.8;
cgSetParameter3fv(myCgFragmentParam_Ke, brassEmissive);
cgSetParameter3fv(myCgFragmentParam_Ka, brassAmbient);
cgSetParameter3fv(myCgFragmentParam_Kd, brassDiffuse);
cgSetParameter3fv(myCgFragmentParam_Ks, brassSpecular);
cgSetParameter1f(myCgFragmentParam_shininess, brassShininess);
}
static void setRedPlasticMaterial(void)
{
const float redPlasticEmissive[3] = {0.0, 0.0, 0.0},
redPlasticAmbient[3] = {0.0, 0.0, 0.0},
redPlasticDiffuse[3] = {0.5, 0.0, 0.0},
redPlasticSpecular[3] = {0.7, 0.6, 0.6},
redPlasticShininess = 32.0;
cgSetParameter3fv(myCgFragmentParam_Ke, redPlasticEmissive);
checkForCgError("setting Ke parameter");
cgSetParameter3fv(myCgFragmentParam_Ka, redPlasticAmbient);
checkForCgError("setting Ka parameter");
cgSetParameter3fv(myCgFragmentParam_Kd, redPlasticDiffuse);
checkForCgError("setting Kd parameter");
cgSetParameter3fv(myCgFragmentParam_Ks, redPlasticSpecular);
checkForCgError("setting Ks parameter");
cgSetParameter1f(myCgFragmentParam_shininess, redPlasticShininess);
checkForCgError("setting shininess parameter");
}
static void setEmissiveLightColorOnly(void)
{
const float zero[3] = {0.0, 0.0, 0.0};
cgSetParameter3fv(myCgFragmentParam_Ke, myLightColor);
checkForCgError("setting Ke parameter");
cgSetParameter3fv(myCgFragmentParam_Ka, zero);
checkForCgError("setting Ka parameter");
cgSetParameter3fv(myCgFragmentParam_Kd, zero);
checkForCgError("setting Kd parameter");
cgSetParameter3fv(myCgFragmentParam_Ks, zero);
checkForCgError("setting Ks parameter");
cgSetParameter1f(myCgFragmentParam_shininess, 0);
checkForCgError("setting shininess parameter");
}
static void display(void)
{
/* World-space positions for light and eye. */
const float eyePosition[4] = { 0, 0, 13, 1 };
const float lightPosition[4] = { 5*sin(myLightAngle),
1.5,
5*cos(myLightAngle), 1 };
float translateMatrix[16], rotateMatrix[16],
modelMatrix[16], invModelMatrix[16], viewMatrix[16],
modelViewMatrix[16], modelViewProjMatrix[16];
float objSpaceEyePosition[4], objSpaceLightPosition[4];
buildLookAtMatrix(eyePosition[0], eyePosition[1], eyePosition[2],
0, 0, 0,
0, 1, 0,
viewMatrix);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
cgGLBindProgram(myCgVertexProgram);
checkForCgError("binding vertex program");
cgGLEnableProfile(myCgVertexProfile);
checkForCgError("enabling vertex profile");
cgGLBindProgram(myCgFragmentProgram);
checkForCgError("binding fragment program");
cgGLEnableProfile(myCgFragmentProfile);
checkForCgError("enabling fragment profile");
/*** Render brass solid sphere ***/
setBrassMaterial();
/* modelView = rotateMatrix * translateMatrix */
makeRotateMatrix(70, 1, 1, 1, rotateMatrix);
makeTranslateMatrix(2, 0, 0, translateMatrix);
multMatrix(modelMatrix, translateMatrix, rotateMatrix);
/* invModelMatrix = inverse(modelMatrix) */
invertMatrix(invModelMatrix, modelMatrix);
/* Transform world-space eye and light positions to sphere's object-space. */
transform(objSpaceEyePosition, invModelMatrix, eyePosition);
cgSetParameter3fv(myCgFragmentParam_eyePosition, objSpaceEyePosition);
transform(objSpaceLightPosition, invModelMatrix, lightPosition);
cgSetParameter3fv(myCgFragmentParam_lightPosition, objSpaceLightPosition);
/* modelViewMatrix = viewMatrix * modelMatrix */
multMatrix(modelViewMatrix, viewMatrix, modelMatrix);
/* modelViewProj = projectionMatrix * modelViewMatrix */
multMatrix(modelViewProjMatrix, myProjectionMatrix, modelViewMatrix);
/* Set matrix parameter with row-major matrix. */
cgSetMatrixParameterfr(myCgVertexParam_modelViewProj, modelViewProjMatrix);
cgUpdateProgramParameters(myCgVertexProgram);
cgUpdateProgramParameters(myCgFragmentProgram);
glutSolidSphere(2.0, 40, 40);
/*** Render red plastic solid cone ***/
setRedPlasticMaterial();
/* modelView = viewMatrix * translateMatrix */
makeTranslateMatrix(-2, -1.5, 0, translateMatrix);
makeRotateMatrix(90, 1, 0, 0, rotateMatrix);
multMatrix(modelMatrix, translateMatrix, rotateMatrix);
/* invModelMatrix = inverse(modelMatrix) */
invertMatrix(invModelMatrix, modelMatrix);
/* Transform world-space eye and light positions to sphere's object-space. */
transform(objSpaceEyePosition, invModelMatrix, eyePosition);
cgSetParameter3fv(myCgFragmentParam_eyePosition, objSpaceEyePosition);
transform(objSpaceLightPosition, invModelMatrix, lightPosition);
cgSetParameter3fv(myCgFragmentParam_lightPosition, objSpaceLightPosition);
/* modelViewMatrix = viewMatrix * modelMatrix */
multMatrix(modelViewMatrix, viewMatrix, modelMatrix);
/* modelViewProj = projectionMatrix * modelViewMatrix */
multMatrix(modelViewProjMatrix, myProjectionMatrix, modelViewMatrix);
/* Set matrix parameter with row-major matrix. */
cgSetMatrixParameterfr(myCgVertexParam_modelViewProj, modelViewProjMatrix);
cgUpdateProgramParameters(myCgVertexProgram);
cgUpdateProgramParameters(myCgFragmentProgram);
glutSolidCone(1.5, 3.5, 30, 30);
/*** Render light as emissive white ball ***/
/* modelView = translateMatrix */
makeTranslateMatrix(lightPosition[0], lightPosition[1], lightPosition[2],
modelMatrix);
/* modelViewMatrix = viewMatrix * modelMatrix */
multMatrix(modelViewMatrix, viewMatrix, modelMatrix);
/* modelViewProj = projectionMatrix * modelViewMatrix */
multMatrix(modelViewProjMatrix, myProjectionMatrix, modelViewMatrix);
setEmissiveLightColorOnly();
/* Avoid degenerate lightPosition. */
cgSetParameter3f(myCgFragmentParam_lightPosition, 0,0,0);
/* Set matrix parameter with row-major matrix. */
cgSetMatrixParameterfr(myCgVertexParam_modelViewProj, modelViewProjMatrix);
cgUpdateProgramParameters(myCgVertexProgram);
cgUpdateProgramParameters(myCgFragmentProgram);
glutSolidSphere(0.2, 12, 12);
cgGLDisableProfile(myCgVertexProfile);
checkForCgError("disabling vertex profile");
cgGLDisableProfile(myCgFragmentProfile);
checkForCgError("disabling fragment profile");
glutSwapBuffers();
}
static void idle(void)
{
myLightAngle += 0.008; /* Add a small angle (in radians). */
if (myLightAngle > 2*myPi) {
myLightAngle -= 2*myPi;
}
glutPostRedisplay();
}
static void keyboard(unsigned char c, int x, int y)
{
static int animating = 0;
switch (c) {
case ' ':
animating = !animating; /* Toggle */
if (animating) {
glutIdleFunc(idle);
} else {
glutIdleFunc(NULL);
}
break;
case 27: /* Esc key */
/* Demonstrate proper deallocation of Cg runtime data structures.
Not strictly necessary if we are simply going to exit. */
cgDestroyProgram(myCgVertexProgram);
cgDestroyContext(myCgContext);
exit(0);
break;
}
}
static void menu(int item)
{
/* Pass menu item character code to keyboard callback. */
keyboard((unsigned char)item, 0, 0);
}
/* Platform-specific code to request synchronized buffer swaps. */
static void requestSynchronizedSwapBuffers(void)
{
#if defined(__APPLE__)
#ifdef CGL_VERSION_1_2
const GLint sync = 1;
#else
const long sync = 1;
#endif
CGLSetParameter(CGLGetCurrentContext(), kCGLCPSwapInterval, &sync);
#elif defined(_WIN32)
if (wglSwapIntervalEXT) {
wglSwapIntervalEXT(1);
}
#else
if (glXSwapIntervalSGI) {
glXSwapIntervalSGI(1);
}
#endif
}
