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#include "math3d.h"
static GLfloat xRot = 0.0f;
static GLfloat yRot = 0.0f;
static void ChangeSize(int w, int h)
{
GLfloat fAspect = (GLfloat) w / (GLfloat) h;
if (h == 0)
h = 1;
glViewport(0, 0, w, h);
/* reset coordinate system */
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
/* produce the perspective projection */
gluPerspective(35.0f, fAspect, 1.0, 40.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
static void SetupRC()
{
GLbyte *pBytes;
GLint iWidth, iHeight, iComponents;
GLenum eFormat;
/* light values and coordinates */
GLfloat whiteLight[] = { 0.05f, 0.05f, 0.05f, 1.0f };
GLfloat sourceLight[] = { 0.75f, 0.75f, 0.75f, 1.0f };
GLfloat lightPos[] = { -10.f, 5.0f, 5.0f, 1.0f };
glEnable(GL_DEPTH_TEST); /* hidden surface removal */
glFrontFace(GL_CCW); /* counter clock-wise polygons face out */
glEnable(GL_CULL_FACE); /* do not calculate inside of a pyramid */
/* enable lighting */
glEnable(GL_LIGHTING);
/* setup and enable light 0 */
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, whiteLight);
glLightfv(GL_LIGHT0, GL_AMBIENT, sourceLight);
glLightfv(GL_LIGHT0, GL_DIFFUSE, sourceLight);
glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
glEnable(GL_LIGHT0);
/* enable color tracking */
glEnable(GL_COLOR_MATERIAL);
/* set Material properties to follow glColor values */
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
/* black blue background */
glClearColor(0.0f, 0.0f, 0.5f, 1.0f);
/* load texture */
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
pBytes = gltLoadTGA("stone.tga", &iWidth, &iHeight, &iComponents, &eFormat);
/* load texture image */
glTexImage2D(GL_TEXTURE_2D, 0, iComponents, iWidth, iHeight, 0, eFormat,
GL_UNSIGNED_BYTE, pBytes);
free(pBytes);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glEnable(GL_TEXTURE_2D);
}
static void SpecialKeys(int key, int x, int y)
{
if (key == GLUT_KEY_UP)
xRot-= 5.0f;
if (key == GLUT_KEY_DOWN)
xRot += 5.0f;
if (key == GLUT_KEY_LEFT)
yRot -= 5.0f;
if (key == GLUT_KEY_RIGHT)
yRot += 5.0f;
xRot = (GLfloat) ((const int) xRot % 360);
yRot = (GLfloat) ((const int) yRot % 360);
glutPostRedisplay();
}
static void RenderScene(void)
{
M3DVector3f vNormal;
M3DVector3f vCorners[5] = {
{ 0.0f, .80f, 0.0f }, /* top 0 */
{ -0.5f, 0.0f, -.5f }, /* back left 1 */
{ 0.5f, 0.0f, -0.5f }, /* back right 2 */
{ 0.5f, 0.0f, 0.5f }, /* front right 3 */
{ -0.5f, 0.0f, 0.5f } /* front left 4 */
};
/* clear the window with current clearing color */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
/* save the matrix state and do the rotations */
glPushMatrix();
/* move object back and do in place rotation */
glTranslatef(0.0f, -0.25f, -4.0f);
glRotatef(xRot, 1.0f, 0.0f, 0.0f);
glRotatef(yRot, 0.0f, 1.0f, 0.0f);
/* draw the pyramid */
glColor3f(1.0f, 1.0f, 1.0f);
glBegin(GL_TRIANGLES);
/* bottom section - two triangles */
glNormal3f(0.0f, -1.0f, 0.0f);
/* map texture to geometry */
glTexCoord2f(1.0f, 1.0f);
glVertex3fv(vCorners[2]);
glTexCoord2f(0.0f, 1.0f);
glVertex3fv(vCorners[4]);
glTexCoord2f(0.0f, 0.0f);
glVertex3fv(vCorners[1]);
glTexCoord2f(1.0f, 1.0f);
glVertex3fv(vCorners[2]);
glTexCoord2f(1.0f, 0.0f);
glVertex3fv(vCorners[3]);
glTexCoord2f(0.0f, 0.0f);
glVertex3fv(vCorners[4]);
/* front face */
m3dFindNormal(vNormal, vCorners[0], vCorners[4], vCorners[3]);
glNormal3fv(vNormal);
glTexCoord2f(0.5f, 1.0f);
glVertex3fv(vCorners[0]);
glTexCoord2f(0.0f, 0.0f);
glVertex3fv(vCorners[4]);
glTexCoord2f(1.0f, 0.0f);
glVertex3fv(vCorners[3]);
/* left face */
m3dFindNormal(vNormal, vCorners[0], vCorners[1], vCorners[4]);
glNormal3fv(vNormal);
glTexCoord2f(0.5f, 1.0f);
glVertex3fv(vCorners[0]);
glTexCoord2f(0.0f, 0.0f);
glVertex3fv(vCorners[1]);
glTexCoord2f(1.0f, 0.0f);
glVertex3fv(vCorners[4]);
/* back face */
m3dFindNormal(vNormal, vCorners[0], vCorners[2], vCorners[1]);
glNormal3fv(vNormal);
glTexCoord2f(0.5f, 1.0f);
glVertex3fv(vCorners[0]);
glTexCoord2f(0.0f, 0.0f);
glVertex3fv(vCorners[2]);
glTexCoord2f(1.0f, 0.0f);
glVertex3fv(vCorners[1]);
/* right face */
m3dFindNormal(vNormal, vCorners[0], vCorners[3], vCorners[2]);
glNormal3fv(vNormal);
glTexCoord2f(0.5f, 1.0f);
glVertex3fv(vCorners[0]);
glTexCoord2f(0.0f, 0.0f);
glVertex3fv(vCorners[3]);
glTexCoord2f(1.0f, 0.0f);
glVertex3fv(vCorners[2]);
glEnd();
/* restore the matrix state */
glPopMatrix();
/* buffer swap */
glutSwapBuffers();
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(640, 480);
glutCreateWindow("Textured Pyramid");
glutReshapeFunc(ChangeSize);
glutSpecialFunc(SpecialKeys);
glutDisplayFunc(RenderScene);
/* initalize glew */
GLenum glewerr = glewInit();
if (GLEW_OK != glewerr)
{
fprintf(stderr, "Error: %s\n", glewGetErrorString(glewerr));
return 1;
}
else
fprintf(stdout, "status: using GLEW %s\n", glewGetString(GLEW_VERSION));
SetupRC();
glutMainLoop();
return 0;
}
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