?? block.c
字號:
// Block.c
// OpenGL SuperBible, Chapter 1
// Demonstrates an assortment of basic 3D concepts
// Program by Richard S. Wright Jr.
#include "../../Common/OpenGLSB.h" // System and OpenGL Stuff
#include "../../Common/GLTools.h" // OpenGL toolkit
#include <math.h>
// Keep track of effects step
int nStep = 0;
// Lighting data
GLfloat lightAmbient[] = { 0.2f, 0.2f, 0.2f, 1.0f };
GLfloat lightDiffuse[] = { 0.7f, 0.7f, 0.7f, 1.0f };
GLfloat lightSpecular[] = { 0.9f, 0.9f, 0.9f };
GLfloat materialColor[] = { 0.8f, 0.0f, 0.0f };
GLfloat lightpos[] = { -80.0f, 120.0f, 100.0f, 0.0f };
GLfloat ground[3][3] = { { 0.0f, -25.0f, 0.0f },
{ 10.0f, -25.0f, 0.0f },
{ 10.0f, -25.0f, -10.0f } };
GLuint textures[4];
// Reduces a normal vector specified as a set of three coordinates,
// to a unit normal vector of length one.
void ReduceToUnit(float vector[3])
{
float length;
// Calculate the length of the vector
length = (float)sqrt((vector[0]*vector[0]) +
(vector[1]*vector[1]) +
(vector[2]*vector[2]));
// Keep the program from blowing up by providing an exceptable
// value for vectors that may calculated too close to zero.
if(length == 0.0f)
length = 1.0f;
// Dividing each element by the length will result in a
// unit normal vector.
vector[0] /= length;
vector[1] /= length;
vector[2] /= length;
}
// Points p1, p2, & p3 specified in counter clock-wise order
void calcNormal(float v[3][3], float out[3])
{
float v1[3],v2[3];
static const int x = 0;
static const int y = 1;
static const int z = 2;
// Calculate two vectors from the three points
v1[x] = v[0][x] - v[1][x];
v1[y] = v[0][y] - v[1][y];
v1[z] = v[0][z] - v[1][z];
v2[x] = v[1][x] - v[2][x];
v2[y] = v[1][y] - v[2][y];
v2[z] = v[1][z] - v[2][z];
// Take the cross product of the two vectors to get
// the normal vector which will be stored in out
out[x] = v1[y]*v2[z] - v1[z]*v2[y];
out[y] = v1[z]*v2[x] - v1[x]*v2[z];
out[z] = v1[x]*v2[y] - v1[y]*v2[x];
// Normalize the vector (shorten length to one)
ReduceToUnit(out);
}
// Creates a shadow projection matrix out of the plane equation
// coefficients and the position of the light. The return value is stored
// in destMat[][]
void MakeShadowMatrix(GLfloat points[3][3], GLfloat lightPos[4], GLfloat destMat[4][4])
{
GLfloat planeCoeff[4];
GLfloat dot;
// Find the plane equation coefficients
// Find the first three coefficients the same way we
// find a normal.
calcNormal(points,planeCoeff);
// Find the last coefficient by back substitutions
planeCoeff[3] = - (
(planeCoeff[0]*points[2][0]) + (planeCoeff[1]*points[2][1]) +
(planeCoeff[2]*points[2][2]));
// Dot product of plane and light position
dot = planeCoeff[0] * lightPos[0] +
planeCoeff[1] * lightPos[1] +
planeCoeff[2] * lightPos[2] +
planeCoeff[3] * lightPos[3];
// Now do the projection
// First column
destMat[0][0] = dot - lightPos[0] * planeCoeff[0];
destMat[1][0] = 0.0f - lightPos[0] * planeCoeff[1];
destMat[2][0] = 0.0f - lightPos[0] * planeCoeff[2];
destMat[3][0] = 0.0f - lightPos[0] * planeCoeff[3];
// Second column
destMat[0][1] = 0.0f - lightPos[1] * planeCoeff[0];
destMat[1][1] = dot - lightPos[1] * planeCoeff[1];
destMat[2][1] = 0.0f - lightPos[1] * planeCoeff[2];
destMat[3][1] = 0.0f - lightPos[1] * planeCoeff[3];
// Third Column
destMat[0][2] = 0.0f - lightPos[2] * planeCoeff[0];
destMat[1][2] = 0.0f - lightPos[2] * planeCoeff[1];
destMat[2][2] = dot - lightPos[2] * planeCoeff[2];
destMat[3][2] = 0.0f - lightPos[2] * planeCoeff[3];
// Fourth Column
destMat[0][3] = 0.0f - lightPos[3] * planeCoeff[0];
destMat[1][3] = 0.0f - lightPos[3] * planeCoeff[1];
destMat[2][3] = 0.0f - lightPos[3] * planeCoeff[2];
destMat[3][3] = dot - lightPos[3] * planeCoeff[3];
}
// Called to draw scene
void RenderScene(void)
{
GLfloat cubeXform[4][4];
// Clear the window with current clearing color
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glShadeModel(GL_SMOOTH);
glEnable(GL_NORMALIZE);
glPushMatrix();
// Draw plane that the cube rests on
glDisable(GL_LIGHTING);
if(nStep == 5)
{
glColor3ub(255,255,255);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, textures[0]);
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-100.0f, -25.3f, -100.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-100.0f, -25.3f, 100.0f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(100.0f, -25.3f, 100.0f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(100.0f, -25.3f, -100.0f);
glEnd();
}
else
{
glColor3f(0.0f, 0.0f, 0.90f); // Blue
glBegin(GL_QUADS);
glVertex3f(-100.0f, -25.3f, -100.0f);
glVertex3f(-100.0f, -25.3f, 100.0f);
glVertex3f(100.0f, -25.3f, 100.0f);
glVertex3f(100.0f, -25.3f, -100.0f);
glEnd();
}
// Set drawing color to Red
glColor3f(1.0f, 0.0f, 0.0f);
// Enable, disable lighting
if(nStep > 2)
{
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glEnable(GL_COLOR_MATERIAL);
glLightfv(GL_LIGHT0, GL_AMBIENT, lightAmbient);
glLightfv(GL_LIGHT0, GL_DIFFUSE, lightDiffuse);
glLightfv(GL_LIGHT0, GL_SPECULAR, lightSpecular);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glMaterialfv(GL_FRONT, GL_SPECULAR,lightSpecular);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, materialColor);
glMateriali(GL_FRONT, GL_SHININESS,128);
}
// Move the cube slightly forward and to the left
glTranslatef(-10.0f, 0.0f, 10.0f);
switch(nStep)
{
// Just draw the wire framed cube
case 0:
glutWireCube(50.0f);
break;
// Same wire cube with hidden line removal simulated
case 1:
// Front Face (before rotation)
glBegin(GL_LINES);
glVertex3f(25.0f,25.0f,25.0f);
glVertex3f(25.0f,-25.0f,25.0f);
glVertex3f(25.0f,-25.0f,25.0f);
glVertex3f(-25.0f,-25.0f,25.0f);
glVertex3f(-25.0f,-25.0f,25.0f);
glVertex3f(-25.0f,25.0f,25.0f);
glVertex3f(-25.0f,25.0f,25.0f);
glVertex3f(25.0f,25.0f,25.0f);
glEnd();
// Top of cube
glBegin(GL_LINES);
// Front Face
glVertex3f(25.0f,25.0f,25.0f);
glVertex3f(25.0f,25.0f,-25.0f);
glVertex3f(25.0f,25.0f,-25.0f);
glVertex3f(-25.0f,25.0f,-25.0f);
glVertex3f(-25.0f,25.0f,-25.0f);
glVertex3f(-25.0f,25.0f,25.0f);
glVertex3f(-25.0f,25.0f,25.0f);
glVertex3f(25.0f,25.0f,25.0f);
glEnd();
// Last two segments for effect
glBegin(GL_LINES);
glVertex3f(25.0f,25.0f,-25.0f);
glVertex3f(25.0f,-25.0f,-25.0f);
glVertex3f(25.0f,-25.0f,-25.0f);
glVertex3f(25.0f,-25.0f,25.0f);
glEnd();
break;
// Uniform colored surface, looks 2D and goofey
case 2:
glutSolidCube(50.0f);
break;
case 3:
glutSolidCube(50.0f);
break;
// Draw a shadow with some lighting
case 4:
glGetFloatv(GL_MODELVIEW_MATRIX, (GLfloat *) cubeXform);
glutSolidCube(50.0f);
glPopMatrix();
// Disable lighting, we'll just draw the shadow as black
glDisable(GL_LIGHTING);
glPushMatrix();
MakeShadowMatrix(ground, lightpos, cubeXform);
glMultMatrixf((GLfloat *)cubeXform);
glTranslatef(-10.0f, 0.0f, 10.0f);
// Set drawing color to Black
glColor3f(0.0f, 0.0f, 0.0f);
glutSolidCube(50.0f);
break;
case 5:
glColor3ub(255,255,255);
glGetFloatv(GL_MODELVIEW_MATRIX, (GLfloat *) cubeXform);
// Front Face (before rotation)
glBindTexture(GL_TEXTURE_2D, textures[1]);
glBegin(GL_QUADS);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(25.0f,25.0f,25.0f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(25.0f,-25.0f,25.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-25.0f,-25.0f,25.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-25.0f,25.0f,25.0f);
glEnd();
// Top of cube
glBindTexture(GL_TEXTURE_2D, textures[2]);
glBegin(GL_QUADS);
// Front Face
glTexCoord2f(0.0f, 0.0f);
glVertex3f(25.0f,25.0f,25.0f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(25.0f,25.0f,-25.0f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(-25.0f,25.0f,-25.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-25.0f,25.0f,25.0f);
glEnd();
// Last two segments for effect
glBindTexture(GL_TEXTURE_2D, textures[3]);
glBegin(GL_QUADS);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(25.0f,25.0f,-25.0f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(25.0f,-25.0f,-25.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(25.0f,-25.0f,25.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(25.0f,25.0f,25.0f);
glEnd();
glPopMatrix();
// Disable lighting, we'll just draw the shadow as black
glDisable(GL_LIGHTING);
glDisable(GL_TEXTURE_2D);
glPushMatrix();
MakeShadowMatrix(ground, lightpos, cubeXform);
glMultMatrixf((GLfloat *)cubeXform);
glTranslatef(-10.0f, 0.0f, 10.0f);
// Set drawing color to Black
glColor3f(0.0f, 0.0f, 0.0f);
glutSolidCube(50.0f);
break;
}
glPopMatrix();
// Flush drawing commands
glutSwapBuffers();
}
// This function does any needed initialization on the rendering
// context.
void SetupRC()
{
GLbyte *pBytes;
GLint nWidth, nHeight, nComponents;
GLenum format;
// Black background
glClearColor(0.0f, 0.0f, 0.0f, 1.0f );
glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE, GL_MODULATE);
glGenTextures(4, textures);
// Load the texture objects
pBytes = gltLoadTGA("floor.tga", &nWidth, &nHeight, &nComponents, &format);
glBindTexture(GL_TEXTURE_2D, textures[0]);
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_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexImage2D(GL_TEXTURE_2D,0,nComponents,nWidth, nHeight, 0,
format, GL_UNSIGNED_BYTE, pBytes);
free(pBytes);
pBytes = gltLoadTGA("Block4.tga", &nWidth, &nHeight, &nComponents, &format);
glBindTexture(GL_TEXTURE_2D, textures[1]);
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_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexImage2D(GL_TEXTURE_2D,0,nComponents,nWidth, nHeight, 0,
format, GL_UNSIGNED_BYTE, pBytes);
free(pBytes);
pBytes = gltLoadTGA("block5.tga", &nWidth, &nHeight, &nComponents, &format);
glBindTexture(GL_TEXTURE_2D, textures[2]);
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_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexImage2D(GL_TEXTURE_2D,0,nComponents,nWidth, nHeight, 0,
format, GL_UNSIGNED_BYTE, pBytes);
free(pBytes);
pBytes = gltLoadTGA("block6.tga", &nWidth, &nHeight, &nComponents, &format);
glBindTexture(GL_TEXTURE_2D, textures[3]);
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_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexImage2D(GL_TEXTURE_2D,0,nComponents,nWidth, nHeight, 0,
format, GL_UNSIGNED_BYTE, pBytes);
free(pBytes);
}
void KeyPressFunc(unsigned char key, int x, int y)
{
if(key == 32)
{
nStep++;
if(nStep > 5)
nStep = 0;
}
// Refresh the Window
glutPostRedisplay();
}
void ChangeSize(int w, int h)
{
// Calculate new clipping volume
GLfloat windowWidth;
GLfloat windowHeight;
// Prevent a divide by zero, when window is too short
// (you cant make a window of zero width).
if(h == 0)
h = 1;
// Keep the square square
if (w <= h)
{
windowHeight = 100.0f*(GLfloat)h/(GLfloat)w;
windowWidth = 100.0f;
}
else
{
windowWidth = 100.0f*(GLfloat)w/(GLfloat)h;
windowHeight = 100.0f;
}
// Set the viewport to be the entire window
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Set the clipping volume
glOrtho(-100.0f, windowWidth, -100.0f, windowHeight, -200.0f, 200.0f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glLightfv(GL_LIGHT0,GL_POSITION, lightpos);
glRotatef(30.0f, 1.0f, 0.0f, 0.0f);
glRotatef(330.0f, 0.0f, 1.0f, 0.0f);
}
int main(int argc, char* argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutCreateWindow("3D Effects Demo");
glutReshapeFunc(ChangeSize);
glutKeyboardFunc(KeyPressFunc);
glutDisplayFunc(RenderScene);
SetupRC();
glutMainLoop();
glDeleteTextures(4,textures);
return 0;
}
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -