Thursday, March 22, 2007
Monday, March 19, 2007
Chales,,,
forgot to give you all the code, well here is what I added to the robot proyect to draw the blasting hand:
void DrawPalm(float xPos,float yPos,float zPos)
{
glPushMatrix();
glColor3f(1.0f,0.0f,0.0f);
glTranslatef(xPos,yPos,zPos);
glScalef(4.0f, 4.0f, 1.0f);
DrawCube(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
void DrawFinger(float xPos, float yPos,float zPos)
{
glPushMatrix();
glColor3f(1.0f,1.0f,1.0f);
glTranslatef(xPos,yPos,zPos);
glPushMatrix();
glScalef(0.5f, 2.0f, 1.0);
DrawCube(0.0f, 0.0f, 0.0f);
glPopMatrix();
glColor3f(0.0f,1.0f,1.0f);
glTranslatef(0.0,0.5,zPos);
glPushMatrix();
glScalef(0.5f, 0.5f, 1.0f);
DrawCube(0.0f,0.0f,0.0f);
glPopMatrix();
glColor3f(1.0,0.0,1.0);
glTranslatef(0.0,0.5,zPos);
glPushMatrix();
glScalef(0.5f, 0.5f, 1.0f);
DrawCube(0.0f,0.0f,0.0f);
glPopMatrix();
glPopMatrix();
}
void DrawThumb(float xPos,float yPos,float zPos)
{
glPushMatrix();
glColor3f(1.0f,1.0f,1.0f);
glTranslatef(xPos,yPos,zPos);
glPushMatrix();
glScalef(2.0f, 1.0f, 1.0f);
DrawCube(0.0f, 0.0f, 0.0f);
glPopMatrix();
glColor3f(0.0f,1.0f,1.0f);
glTranslatef(1.0,0,zPos);
glPushMatrix();
glScalef(1.0f,1.0f,1.0f);
DrawCube(0.0f,0.0f,0.0f);
glPopMatrix();
glColor3f(1.0,0.0,1.0);
glTranslatef(0.5,0,zPos);
glPushMatrix();
glScalef(0.5f,1.0f,1.0f);
DrawCube(0.0f,0.0f,0.0f);
glPopMatrix();
glPopMatrix();
}
void DrawHand(float xPos,float yPos,float zPos)
{
//DrawHand();
DrawPalm(10.0f,2.0f,0.0f);
DrawFinger(10.0f,4.0f,-1.0f);
DrawFinger(9.0f,4.0f,-0.5f);
DrawFinger(8.0f,4.0f,-0.5f);
DrawFinger(7.0f,4.0f,-0.5f);
DrawThumb(12.0f,-1.0f,-2.0);
}
forgot to give you all the code, well here is what I added to the robot proyect to draw the blasting hand:
void DrawPalm(float xPos,float yPos,float zPos)
{
glPushMatrix();
glColor3f(1.0f,0.0f,0.0f);
glTranslatef(xPos,yPos,zPos);
glScalef(4.0f, 4.0f, 1.0f);
DrawCube(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
void DrawFinger(float xPos, float yPos,float zPos)
{
glPushMatrix();
glColor3f(1.0f,1.0f,1.0f);
glTranslatef(xPos,yPos,zPos);
glPushMatrix();
glScalef(0.5f, 2.0f, 1.0);
DrawCube(0.0f, 0.0f, 0.0f);
glPopMatrix();
glColor3f(0.0f,1.0f,1.0f);
glTranslatef(0.0,0.5,zPos);
glPushMatrix();
glScalef(0.5f, 0.5f, 1.0f);
DrawCube(0.0f,0.0f,0.0f);
glPopMatrix();
glColor3f(1.0,0.0,1.0);
glTranslatef(0.0,0.5,zPos);
glPushMatrix();
glScalef(0.5f, 0.5f, 1.0f);
DrawCube(0.0f,0.0f,0.0f);
glPopMatrix();
glPopMatrix();
}
void DrawThumb(float xPos,float yPos,float zPos)
{
glPushMatrix();
glColor3f(1.0f,1.0f,1.0f);
glTranslatef(xPos,yPos,zPos);
glPushMatrix();
glScalef(2.0f, 1.0f, 1.0f);
DrawCube(0.0f, 0.0f, 0.0f);
glPopMatrix();
glColor3f(0.0f,1.0f,1.0f);
glTranslatef(1.0,0,zPos);
glPushMatrix();
glScalef(1.0f,1.0f,1.0f);
DrawCube(0.0f,0.0f,0.0f);
glPopMatrix();
glColor3f(1.0,0.0,1.0);
glTranslatef(0.5,0,zPos);
glPushMatrix();
glScalef(0.5f,1.0f,1.0f);
DrawCube(0.0f,0.0f,0.0f);
glPopMatrix();
glPopMatrix();
}
void DrawHand(float xPos,float yPos,float zPos)
{
//DrawHand();
DrawPalm(10.0f,2.0f,0.0f);
DrawFinger(10.0f,4.0f,-1.0f);
DrawFinger(9.0f,4.0f,-0.5f);
DrawFinger(8.0f,4.0f,-0.5f);
DrawFinger(7.0f,4.0f,-0.5f);
DrawThumb(12.0f,-1.0f,-2.0);
}
With that done, perhaps we need to give the robots little hands, so they can trwirl their partners around, or give high fives to cool dancing couples...
yeah, they need hands:
Here is a little hand I made for all theseive objectives----------------------------------->
In this picture, the hand is flexed a little as to give an image that it is holding something, or maybe scatching a fat belly. We can articulate the fingers as to make the hand hold or not something. We can also make the hand wave.
ich esse, was ich mag, und leide, was ich muss...
ich esse, was ich mag, und leide,was ich muss....
And as usual, here is the code,
Magic Dancing Robot, do your thing!
....................................
Now we´re going to check out a nice ball dance between my dear robot friends I have been building.
Here´s the code:
* i just added more robots to the scene that´s all:
#pragma comment(linker, "/subsystem:windows")
#include
#include
#include
#include
/* . These variables will control angles,
fullscreen, and the global device context.
*/
HDC g_HDC;
float
angle = 0.0f;
float
legAngle[2] = {0.0f, 0.0f};
float
armAngle[2] = {0.0f, 0.0f};
bool
fullScreen = false;
/* Function: DrawSquare
Purpose: As the name would suggest, this is
the function for drawing the cubes.
*/
void
DrawSquare(float xPos, float yPos, float zPos)
{
glPushMatrix();
glBegin(GL_POLYGON);
/* This is the front face*/
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(-1.0f, 0.0f, 0.0f);
glVertex3f(-1.0f, -1.0f, 0.0f);
glVertex3f(0.0f, -1.0f, 0.0f);
glEnd();
glPopMatrix();
}
/* Function: DrawArm
Purpose: This function draws the arm
for the robot.
*/
void
DrawArm(float xPos, float yPos, float zPos)
{
glPushMatrix();
/* Sets color to red*/
glColor3f(1.0f, 0.0f, 0.0f);
glTranslatef(xPos, yPos, zPos);
/* Creates 1 x 4 x 1 cube*/
glScalef(1.0f, 4.0f, 1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
/* This will draw the gross part of the arm.*/
glPushMatrix();
/* Sets color to red*/
glColor3f(0.0f, 1.0f, 0.0f);
glTranslatef(xPos+1, yPos-4.0f, zPos);
/* Creates 1 x 4 x 1 cube*/
glScalef(2.0f, 2.0f, 1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
/* This will draw the robot´s hand*/
glPushMatrix();
/* Sets color to red*/
glColor3f(1.0f, 1.0f, 1.0f);
glTranslatef(xPos+1, yPos-6.0f, zPos);
/* Creates 1 x 4 x 1 cube*/
glScalef(1.0f, 1.0f, 1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
/* Function: DrawHead
Purpose: This function will create the
head for the robot.
*/
void
DrawHead(float xPos, float yPos, float zPos)
{
glPushMatrix();
/* Sets color to white*/
glColor3f(1.0f, 1.0f, 1.0f);
glTranslatef(xPos, yPos, zPos);
/* Creates 2 x 2 x 2 cube*/
glScalef(2.0f, 2.0f, 2.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
/* Function: DrawTorso
Purpose: Function will do as suggested
and draw a torso for our robot.
*/
void
DrawTorso(float xPos, float yPos, float zPos)
{
glPushMatrix();
/* Sets color to blue*/
glColor3f(0.0f, 0.0f, 1.0f);
glTranslatef(xPos, yPos, zPos);
/* Creates 3 x 5 x 1 cube*/
glScalef(3.0f, 5.0f, 1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
/* Function: DrawLeg
Purpose: Not to sound repetitve, but as suggested
this function will draw our robots legs.
*/
void
DrawLeg(float xPos, float yPos, float zPos)
{
glPushMatrix();
/* Sets color to yellow*/
glColor3f(0.0f, 0.0f, 1.0f);
glTranslatef(xPos, yPos, zPos);
/* Creates 1 x 5 x 1 cube*/
glScalef(1.0f, 5.0f, 1.0f);
DrawSquare(1.0f, 0.0f, 0.0f);
glPopMatrix();
/*This will draw the gross part of the leg for the robot.*/
glPushMatrix();
glColor3f(1.0f,1.0f,1.0f);
glTranslatef(xPos,yPos-5,zPos);
glScalef(2.0f,5.0f,1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
/*This will draw the robot´s foot*/
glPushMatrix();
glColor3f(0.0f,1.0f,0.0f);
glTranslatef(xPos,yPos-10,zPos);
glScalef(3.0f,2.0f,1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
/* Function: DrawRobot
Purpose: Function to draw our entire robot
*/
void
DrawRobot(float xPos, float yPos, float zPos)
{
/* Variables for state of robots legs. True
means the leg is forward, and False means
the leg is back. The same applies to the
robots arm states.
*/
static bool leg1 = true;
static bool leg2 = false;
static bool arm1 = true;
static bool arm2 = false;
glPushMatrix();
/* This will draw our robot at the
desired coordinates.
*/
glTranslatef(xPos, yPos, zPos);
/* These three lines will draw the
various components of our robot.
*/
DrawHead(1.0f, 2.0f, 0.0f);
DrawTorso(1.5f, 0.0f, 0.0f);
glPushMatrix();
/* If the arm is moving forward we will increase
the angle; otherwise, we will decrease the
angle.
*/
if (arm1)
{
armAngle[0] = armAngle[0] + 1.0f;
}
else
{
armAngle[0] = armAngle[0] - 1.0f;
}
/* Once the arm has reached its max angle
in one direction, we want it to reverse
and change direction.
*/
if (armAngle[0] >= 15.0f)
{
arm1 =
false;
}
if (armAngle[0] <= 15.0f) { arm1 = true; } /* Here we are going to move the arm away from the torso and rotate. This will create a walking effect. */ glTranslatef(0.0f, -0.5f, 0.0f); glRotatef(armAngle[0], 1.0f, 0.0f, 0.0f); DrawArm(2.5f, 0.0f, -0.5f); glPopMatrix(); glPushMatrix(); /* If the arm is moving forward we will increase the angle, otherwise we will decrease the angle */ if (arm2) { armAngle[1] = armAngle[1] + 1.0f; } else { armAngle[1] = armAngle[1] - 1.0f; } /* Here we are going to move the arm away from the torso and rotate. This will create a walking effect. */ glTranslatef(0.0f, -0.5f, 0.0f); glRotatef(armAngle[1], 1.0f, 0.0f, 0.0f); DrawArm(-1.5f, 0.0f, -0.5f); glPopMatrix(); /* Now its time to rotate the legs relative to the robots position in the world, this is the first leg, ie the right one. */ glPushMatrix(); /* If the leg is moving forward we will increase the angle; otherwise, we will decrease the angle. */ if (leg1) { legAngle[0] = legAngle[0] + 1.0f; } else { legAngle[0] = legAngle[0] - 1.0f; } /* Once the leg has reached its max angle in one direction, we want it to reverse and change direction. */ if (legAngle[0] >= 15.0f)
{
leg1 =
false;
}
if (legAngle[0] <= -15.0f) { leg1 = true; } /* Here we are going to move the leg away from the torso and rotate. This will create a walking effect. */ glTranslatef(0.0f, -0.5f, 0.0f); glRotatef(legAngle[0], 1.0f, 0.0f, 0.0f); /* Time to draw the leg. */ DrawLeg(-0.5f, -5.0f, -0.5f); glPopMatrix(); /* Same as above, for the left leg. */ glPushMatrix(); /* If the leg is moving forward we will increase the angle, otherwise we will decrease the angle */ if (leg2) { legAngle[1] = legAngle[1] + 1.0f; } else { legAngle[1] = legAngle[1] - 1.0f; } /* Once the leg has reached its max angle in one direction, we want it to reverse and change direction. */ if (legAngle[1] >= 15.0f)
{
leg2 =
false;
}
if (legAngle[1] <= -15.0f) { leg2 = true; } /* Here we are going to move the leg away from the torso and rotate. This will create a walking effect. */ glTranslatef(0.0f, -0.5f, 0.0f); glRotatef(legAngle[1], 1.0f, 0.0f, 0.0f); DrawLeg(1.5f, -5.0f, -0.5f); glPopMatrix(); glPopMatrix(); } /* Function: Render Purpose: This function will be responsible for the rendering, got to love my descriptive function names : ) */ void Render() { /* Enable depth testing */ glEnable(GL_DEPTH_TEST); /* Heres our rendering. Clears the screen to black, clear the color and depth buffers, and reset our modelview matrix. */ glClearColor(0.0f, 0.0f, 0.0f, 0.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); /* Increase rotation angle counter */ angle = angle + 1.0f; /* Reset after we have completed a circle */ if (angle >= 360.0f)
{
angle = 0.0f;
}
glPushMatrix();
glLoadIdentity();
/* Move to 0,0,-30 , rotate the robot on
its y axis, draw the robot, and dispose
of the current matrix.
*/
glTranslatef(0.0f, 0.0f, -30.0f);
glRotatef(angle, 0.0f, 1.0f, 0.0f);
DrawRobot(0.0f, 0.0f, 0.0f);
glPopMatrix();
glFlush();
glPushMatrix();
glLoadIdentity();
/* Move to 0,0,-30 , rotate the robot on
its y axis, draw the robot, and dispose
of the current matrix.
*/
glScalef(2,.5,1);
glRotatef(angle, 0.0f, 0.0f, 1.0f);
glTranslatef(-3.0f, 1.0f, 2.0f);
DrawRobot(0.0f, 0.0f, 0.0f);
glPopMatrix();
glFlush();
glPushMatrix();
glLoadIdentity();
/* Move to 0,0,-30 , rotate the robot on
its y axis, draw the robot, and dispose
of the current matrix.
*/
glScalef(.5,.5,.5);
glRotatef(angle, 0.0f, 1.0f, 0.0f);
glTranslatef(5.0f, 0.0f, 2.0f);
DrawRobot(0.0f, 0.0f, 0.0f);
glPopMatrix();
glFlush();
glPushMatrix();
glLoadIdentity();
/* Move to 0,0,-30 , rotate the robot on
its y axis, draw the robot, and dispose
of the current matrix.
*/
glTranslatef(1.0f, 1.0f, 1.0f);
glRotatef(angle, 1.0f, 0.0f, 0.0f);
glScalef(.5,-1.5,.5);
DrawRobot(0.0f, 0.0f, 0.0f);
glPopMatrix();
glFlush();
glPushMatrix();
glLoadIdentity();
/* Move to 0,0,-30 , rotate the robot on
its y axis, draw the robot, and dispose
of the current matrix.
*/
glRotatef(angle, 0.0f, 1.0f, 0.0f);
glTranslatef(-2.0f, -1.0f, 3.0f);
DrawRobot(0.0f, 0.0f, 0.0f);
glPopMatrix();
/* Bring back buffer to foreground
*/
SwapBuffers(g_HDC);
}
//function to set the pixel format for the device context
/* Function: SetupPixelFormat
Purpose: This function will be responsible
for setting the pixel format for the
device context.
*/
void
SetupPixelFormat(HDC hDC)
{
/* Pixel format index
*/
int nPixelFormat;
static PIXELFORMATDESCRIPTOR pfd = {
sizeof(PIXELFORMATDESCRIPTOR), //size of structure
1,
//default version
PFD_DRAW_TO_WINDOW |
//window drawing support
PFD_SUPPORT_OPENGL |
//opengl support
PFD_DOUBLEBUFFER,
//double buffering support
PFD_TYPE_RGBA,
//RGBA color mode
32,
//32 bit color mode
0, 0, 0, 0, 0, 0,
//ignore color bits
0,
//no alpha buffer
0,
//ignore shift bit
0,
//no accumulation buffer
0, 0, 0, 0,
//ignore accumulation bits
16,
//16 bit z-buffer size
0,
//no stencil buffer
0,
//no aux buffer
PFD_MAIN_PLANE,
//main drawing plane
0,
//reserved
0, 0, 0 };
//layer masks ignored
/* Choose best matching format*/
nPixelFormat = ChoosePixelFormat(hDC, &pfd);
/* Set the pixel format to the device context*/
SetPixelFormat(hDC, nPixelFormat, &pfd);
}
/* Windows Event Procedure Handler
*/
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
/* Rendering and Device Context
variables are declared here.
*/
static HGLRC hRC;
static HDC hDC;
/* Width and Height for the
window our robot is to be
displayed in.
*/
int width, height;
switch(message)
{
case WM_CREATE: //window being created
hDC = GetDC(hwnd);
//get current windows device context
g_HDC = hDC;
SetupPixelFormat(hDC);
//call our pixel format setup function
/* Create rendering context and make it current
*/
hRC = wglCreateContext(hDC);
wglMakeCurrent(hDC, hRC);
return 0;
break;
case WM_CLOSE: //window is closing
/* Deselect rendering context and delete it*/
wglMakeCurrent(hDC, NULL);
wglDeleteContext(hRC);
/* Send quit message to queue*/
PostQuitMessage(0);
return 0;
break;
case WM_SIZE:
/* Retrieve width and height*/
height = HIWORD(lParam);
width = LOWORD(lParam);
/* Don't want a divide by 0*/
if (height == 0)
{
height = 1;
}
/* Reset the viewport to new dimensions*/
glViewport(0, 0, width, height);
/* Set current Matrix to projection*/
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
//reset projection matrix
/* Time to calculate aspect ratio of
our window.
*/
gluPerspective(54.0f, (GLfloat)width/(GLfloat)height, 1.0f, 1000.0f);
glMatrixMode(GL_MODELVIEW);
//set modelview matrix
glLoadIdentity();
//reset modelview matrix
return 0;
break;
default:
break;
}
return (DefWindowProc(hwnd, message, wParam, lParam));
}
int
APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
WNDCLASSEX windowClass;
//window class
HWND hwnd;
//window handle
MSG msg;
//message
bool done; //flag for completion of app
DWORD dwExStyle;
//window extended style
DWORD dwStyle;
//window style
RECT windowRect;
/* Screen/display attributes*/
int width = 800;
int height = 600;
int bits = 32;
windowRect.left =(
long)0; //set left value to 0
windowRect.right =(
long)width; //set right value to requested width
windowRect.top =(
long)0; //set top value to 0
windowRect.bottom =(
long)height;//set bottom value to requested height
/* Fill out the window class structure*/
windowClass.cbSize =
sizeof(WNDCLASSEX);
windowClass.style = CS_HREDRAW | CS_VREDRAW;
windowClass.lpfnWndProc = WndProc;
windowClass.cbClsExtra = 0;
windowClass.cbWndExtra = 0;
windowClass.hInstance = hInstance;
windowClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
windowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
windowClass.hbrBackground = NULL;
windowClass.lpszMenuName = NULL;
windowClass.lpszClassName =
"MyClass";
windowClass.hIconSm = LoadIcon(NULL, IDI_WINLOGO);
/* Register window class*/
if (!RegisterClassEx(&windowClass))
{
return 0;
}
/* Check if fullscreen is on*/
if (fullScreen)
{
DEVMODE dmScreenSettings;
memset(&dmScreenSettings, 0,
sizeof(dmScreenSettings));
dmScreenSettings.dmSize =
sizeof(dmScreenSettings);
dmScreenSettings.dmPelsWidth = width;
//screen width
dmScreenSettings.dmPelsHeight = height;
//screen height
dmScreenSettings.dmBitsPerPel = bits;
//bits per pixel
dmScreenSettings.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;
if (ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN !=
DISP_CHANGE_SUCCESSFUL))
{
/* Setting display mode failed, switch to windowed*/
MessageBox(NULL,
"Display mode failed", NULL, MB_OK);
fullScreen =
false;
}
}
/* Check if fullscreen is still on*/
if (fullScreen)
{
dwExStyle = WS_EX_APPWINDOW;
//window extended style
dwStyle = WS_POPUP;
//windows style
ShowCursor(FALSE);
//hide mouse pointer
}
else
{
dwExStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;
//window extended style
dwStyle = WS_OVERLAPPEDWINDOW;
//windows style
}
AdjustWindowRectEx(&windowRect, dwStyle, FALSE, dwExStyle);
/* Class registerd, so now create our window*/
hwnd = CreateWindowEx(NULL,
"MyClass", //class name
"OpenGL Robot", //app name
dwStyle |
WS_CLIPCHILDREN |
WS_CLIPSIBLINGS,
0, 0,
//x and y coords
windowRect.right - windowRect.left,
windowRect.bottom - windowRect.top,
//width, height
NULL,
//handle to parent
NULL,
//handle to menu
hInstance,
//application instance
NULL);
//no xtra params
/* Check if window creation failed (hwnd = null ?)*/
if (!hwnd)
{
return 0;
}
ShowWindow(hwnd, SW_SHOW);
//display window
UpdateWindow(hwnd);
//update window
done =
false; //initialize loop condition variable
/* Main message loop*/
while (!done)
{
PeekMessage(&msg, hwnd, NULL, NULL, PM_REMOVE);
if (msg.message == WM_QUIT) //did we revieve a quit message?
{
done =
true;
}
else
{
Render();
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
if (fullScreen)
{
ChangeDisplaySettings(NULL, 0);
ShowCursor(TRUE);
}
return msg.wParam;
}
Tuesday, March 13, 2007
Another nice morning to just get up and write...
As I promised last week, I did some reading on Open Gl, and I made a new program which displays now a dancing robot on the screen. This program was actually much more easier to do than the last one I showed here, since I finally understood how to use the functions glPushMatrix and glPopMatrix. Why are these two functions important ?
If you decide not to implement them, and just end up using glTranslatef(xPos,yPos-10,zPos) or glScale etc, what´s going to be happening is that you`re going to be moving your whole scene or scaling your whole scene, so you will loose power in saying what it is you want to move or scale. Let´s say you already drew correctly the robot´s head and torso, and you just wanted to add the robot´s right arm, you wnat the piece of code you already drew to stay put, you don´t need it to be moving around, you woulkd just have to move the new arm figure to upper shoulder. To acomplish this, you use Pop and Push. You are actually drawing once again the robot, but the stack is keeping the order in which the robot to be drawn, and it just moves what you ask it to, what you push into or pop out of the stack.
Anyway, perhaps it will be a lot more clearer with a piece of code:
.....................................................................................................................................................................
#pragma comment(linker, "/subsystem:windows")
#include
#include
#include
#include
/* . These variables will control angles,
fullscreen, and the global device context.
*/
HDC g_HDC;
float
angle = 0.0f;
float
legAngle[2] = {0.0f, 0.0f};
float
armAngle[2] = {0.0f, 0.0f};
bool
fullScreen = false;
/* Function: DrawSquare
Purpose: As the name would suggest, this is
the function for drawing the cubes.
*/
void
DrawSquare(float xPos, float yPos, float zPos)
{
glPushMatrix();
glBegin(GL_POLYGON);
/* This is the front face*/
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(-1.0f, 0.0f, 0.0f);
glVertex3f(-1.0f, -1.0f, 0.0f);
glVertex3f(0.0f, -1.0f, 0.0f);
glEnd();
glPopMatrix();
}
/* Function: DrawArm
Purpose: This function draws the arm
for the robot.
*/
void
DrawArm(float xPos, float yPos, float zPos)
{
glPushMatrix();
/* Sets color to red*/
glColor3f(1.0f, 0.0f, 0.0f);
glTranslatef(xPos, yPos, zPos);
/* Creates 1 x 4 x 1 cube*/
glScalef(1.0f, 4.0f, 1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
/* This will draw the gross part of the arm.*/
glPushMatrix();
/* Sets color to red*/
glColor3f(0.0f, 1.0f, 0.0f);
glTranslatef(xPos+1, yPos-4.0f, zPos);
/* Creates 1 x 4 x 1 cube*/
glScalef(2.0f, 2.0f, 1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
/* This will draw the robot´s hand*/
glPushMatrix();
/* Sets color to red*/
glColor3f(1.0f, 1.0f, 1.0f);
glTranslatef(xPos+1, yPos-6.0f, zPos);
/* Creates 1 x 4 x 1 cube*/
glScalef(1.0f, 1.0f, 1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
/* Function: DrawHead
Purpose: This function will create the
head for the robot.
*/
void
DrawHead(float xPos, float yPos, float zPos)
{
glPushMatrix();
/* Sets color to white*/
glColor3f(1.0f, 1.0f, 1.0f);
glTranslatef(xPos, yPos, zPos);
/* Creates 2 x 2 x 2 cube*/
glScalef(2.0f, 2.0f, 2.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
/* Function: DrawTorso
Purpose: Function will do as suggested
and draw a torso for our robot.
*/
void
DrawTorso(float xPos, float yPos, float zPos)
{
glPushMatrix();
/* Sets color to blue*/
glColor3f(0.0f, 0.0f, 1.0f);
glTranslatef(xPos, yPos, zPos);
/* Creates 3 x 5 x 1 cube*/
glScalef(3.0f, 5.0f, 1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
/* Function: DrawLeg
Purpose: Not to sound repetitve, but as suggested
this function will draw our robots legs.
*/
void
DrawLeg(float xPos, float yPos, float zPos)
{
glPushMatrix();
/* Sets color to yellow*/
glColor3f(0.0f, 0.0f, 1.0f);
glTranslatef(xPos, yPos, zPos);
/* Creates 1 x 5 x 1 cube*/
glScalef(1.0f, 5.0f, 1.0f);
DrawSquare(1.0f, 0.0f, 0.0f);
glPopMatrix();
/*This will draw the gross part of the leg for the robot.*/
glPushMatrix();
glColor3f(1.0f,1.0f,1.0f);
glTranslatef(xPos,yPos-5,zPos);
glScalef(2.0f,5.0f,1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
/*This will draw the robot´s foot*/
glPushMatrix();
glColor3f(0.0f,1.0f,0.0f);
glTranslatef(xPos,yPos-10,zPos);
glScalef(3.0f,2.0f,1.0f);
DrawSquare(0.0f, 0.0f, 0.0f);
glPopMatrix();
}
/* Function: DrawRobot
Purpose: Function to draw our entire robot
*/
void
DrawRobot(float xPos, float yPos, float zPos)
{
/* Variables for state of robots legs. True
means the leg is forward, and False means
the leg is back. The same applies to the
robots arm states.
*/
static bool leg1 = true;
static bool leg2 = false;
static bool arm1 = true;
static bool arm2 = false;
glPushMatrix();
/* This will draw our robot at the
desired coordinates.
*/
glTranslatef(xPos, yPos, zPos);
/* These three lines will draw the
various components of our robot.
*/
DrawHead(1.0f, 2.0f, 0.0f);
DrawTorso(1.5f, 0.0f, 0.0f);
glPushMatrix();
/* If the arm is moving forward we will increase
the angle; otherwise, we will decrease the
angle.
*/
if (arm1)
{
armAngle[0] = armAngle[0] + 1.0f;
}
else
{
armAngle[0] = armAngle[0] - 1.0f;
}
/* Once the arm has reached its max angle
in one direction, we want it to reverse
and change direction.
*/
if (armAngle[0] >= 15.0f)
{
arm1 =
false;
}
if (armAngle[0] <= 15.0f) { arm1 = true; } /* Here we are going to move the arm away from the torso and rotate. This will create a walking effect. */ glTranslatef(0.0f, -0.5f, 0.0f); glRotatef(armAngle[0], 1.0f, 0.0f, 0.0f); DrawArm(2.5f, 0.0f, -0.5f); glPopMatrix(); glPushMatrix(); /* If the arm is moving forward we will increase the angle, otherwise we will decrease the angle */ if (arm2) { armAngle[1] = armAngle[1] + 1.0f; } else { armAngle[1] = armAngle[1] - 1.0f; } /* Here we are going to move the arm away from the torso and rotate. This will create a walking effect. */ glTranslatef(0.0f, -0.5f, 0.0f); glRotatef(armAngle[1], 1.0f, 0.0f, 0.0f); DrawArm(-1.5f, 0.0f, -0.5f); glPopMatrix(); /* Now its time to rotate the legs relative to the robots position in the world, this is the first leg, ie the right one. */ glPushMatrix(); /* If the leg is moving forward we will increase the angle; otherwise, we will decrease the angle. */ if (leg1) { legAngle[0] = legAngle[0] + 1.0f; } else { legAngle[0] = legAngle[0] - 1.0f; } /* Once the leg has reached its max angle in one direction, we want it to reverse and change direction. */ if (legAngle[0] >= 15.0f)
{
leg1 =
false;
}
if (legAngle[0] <= -15.0f) { leg1 = true; } /* Here we are going to move the leg away from the torso and rotate. This will create a walking effect. */ glTranslatef(0.0f, -0.5f, 0.0f); glRotatef(legAngle[0], 1.0f, 0.0f, 0.0f); /* Time to draw the leg. */ DrawLeg(-0.5f, -5.0f, -0.5f); glPopMatrix(); /* Same as above, for the left leg. */ glPushMatrix(); /* If the leg is moving forward we will increase the angle, otherwise we will decrease the angle */ if (leg2) { legAngle[1] = legAngle[1] + 1.0f; } else { legAngle[1] = legAngle[1] - 1.0f; } /* Once the leg has reached its max angle in one direction, we want it to reverse and change direction. */ if (legAngle[1] >= 15.0f)
{
leg2 =
false;
}
if (legAngle[1] <= -15.0f) { leg2 = true; } /* Here we are going to move the leg away from the torso and rotate. This will create a walking effect. */ glTranslatef(0.0f, -0.5f, 0.0f); glRotatef(legAngle[1], 1.0f, 0.0f, 0.0f); DrawLeg(1.5f, -5.0f, -0.5f); glPopMatrix(); glPopMatrix(); } /* Function: Render Purpose: This function will be responsible for the rendering, got to love my descriptive function names : ) */ void Render() { /* Enable depth testing */ glEnable(GL_DEPTH_TEST); /* Heres our rendering. Clears the screen to black, clear the color and depth buffers, and reset our modelview matrix. */ glClearColor(0.0f, 0.0f, 0.0f, 0.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); /* Increase rotation angle counter */ angle = angle + 1.0f; /* Reset after we have completed a circle */ if (angle >= 360.0f)
{
angle = 0.0f;
}
glPushMatrix();
glLoadIdentity();
/* Move to 0,0,-30 , rotate the robot on
its y axis, draw the robot, and dispose
of the current matrix.
*/
glTranslatef(0.0f, 0.0f, -30.0f);
glRotatef(angle, 0.0f, 1.0f, 0.0f);
DrawRobot(0.0f, 0.0f, 0.0f);
glPopMatrix();
glFlush();
/* Bring back buffer to foreground
*/
SwapBuffers(g_HDC);
}
//function to set the pixel format for the device context
/* Function: SetupPixelFormat
Purpose: This function will be responsible
for setting the pixel format for the
device context.
*/
void
SetupPixelFormat(HDC hDC)
{
/* Pixel format index
*/
int nPixelFormat;
static PIXELFORMATDESCRIPTOR pfd = {
sizeof(PIXELFORMATDESCRIPTOR), //size of structure
1,
//default version
PFD_DRAW_TO_WINDOW |
//window drawing support
PFD_SUPPORT_OPENGL |
//opengl support
PFD_DOUBLEBUFFER,
//double buffering support
PFD_TYPE_RGBA,
//RGBA color mode
32,
//32 bit color mode
0, 0, 0, 0, 0, 0,
//ignore color bits
0,
//no alpha buffer
0,
//ignore shift bit
0,
//no accumulation buffer
0, 0, 0, 0,
//ignore accumulation bits
16,
//16 bit z-buffer size
0,
//no stencil buffer
0,
//no aux buffer
PFD_MAIN_PLANE,
//main drawing plane
0,
//reserved
0, 0, 0 };
//layer masks ignored
/* Choose best matching format*/
nPixelFormat = ChoosePixelFormat(hDC, &pfd);
/* Set the pixel format to the device context*/
SetPixelFormat(hDC, nPixelFormat, &pfd);
}
/* Windows Event Procedure Handler
*/
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
/* Rendering and Device Context
variables are declared here.
*/
static HGLRC hRC;
static HDC hDC;
/* Width and Height for the
window our robot is to be
displayed in.
*/
int width, height;
switch(message)
{
case WM_CREATE: //window being created
hDC = GetDC(hwnd);
//get current windows device context
g_HDC = hDC;
SetupPixelFormat(hDC);
//call our pixel format setup function
/* Create rendering context and make it current
*/
hRC = wglCreateContext(hDC);
wglMakeCurrent(hDC, hRC);
return 0;
break;
case WM_CLOSE: //window is closing
/* Deselect rendering context and delete it*/
wglMakeCurrent(hDC, NULL);
wglDeleteContext(hRC);
/* Send quit message to queue*/
PostQuitMessage(0);
return 0;
break;
case WM_SIZE:
/* Retrieve width and height*/
height = HIWORD(lParam);
width = LOWORD(lParam);
/* Don't want a divide by 0*/
if (height == 0)
{
height = 1;
}
/* Reset the viewport to new dimensions*/
glViewport(0, 0, width, height);
/* Set current Matrix to projection*/
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
//reset projection matrix
/* Time to calculate aspect ratio of
our window.
*/
gluPerspective(54.0f, (GLfloat)width/(GLfloat)height, 1.0f, 1000.0f);
glMatrixMode(GL_MODELVIEW);
//set modelview matrix
glLoadIdentity();
//reset modelview matrix
return 0;
break;
default:
break;
}
return (DefWindowProc(hwnd, message, wParam, lParam));
}
int
APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
WNDCLASSEX windowClass;
//window class
HWND hwnd;
//window handle
MSG msg;
//message
bool done; //flag for completion of app
DWORD dwExStyle;
//window extended style
DWORD dwStyle;
//window style
RECT windowRect;
/* Screen/display attributes*/
int width = 800;
int height = 600;
int bits = 32;
windowRect.left =(
long)0; //set left value to 0
windowRect.right =(
long)width; //set right value to requested width
windowRect.top =(
long)0; //set top value to 0
windowRect.bottom =(
long)height;//set bottom value to requested height
/* Fill out the window class structure*/
windowClass.cbSize =
sizeof(WNDCLASSEX);
windowClass.style = CS_HREDRAW | CS_VREDRAW;
windowClass.lpfnWndProc = WndProc;
windowClass.cbClsExtra = 0;
windowClass.cbWndExtra = 0;
windowClass.hInstance = hInstance;
windowClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
windowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
windowClass.hbrBackground = NULL;
windowClass.lpszMenuName = NULL;
windowClass.lpszClassName =
"MyClass";
windowClass.hIconSm = LoadIcon(NULL, IDI_WINLOGO);
/* Register window class*/
if (!RegisterClassEx(&windowClass))
{
return 0;
}
/* Check if fullscreen is on*/
if (fullScreen)
{
DEVMODE dmScreenSettings;
memset(&dmScreenSettings, 0,
sizeof(dmScreenSettings));
dmScreenSettings.dmSize =
sizeof(dmScreenSettings);
dmScreenSettings.dmPelsWidth = width;
//screen width
dmScreenSettings.dmPelsHeight = height;
//screen height
dmScreenSettings.dmBitsPerPel = bits;
//bits per pixel
dmScreenSettings.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;
if (ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN !=
DISP_CHANGE_SUCCESSFUL))
{
/* Setting display mode failed, switch to windowed*/
MessageBox(NULL,
"Display mode failed", NULL, MB_OK);
fullScreen =
false;
}
}
/* Check if fullscreen is still on*/
if (fullScreen)
{
dwExStyle = WS_EX_APPWINDOW;
//window extended style
dwStyle = WS_POPUP;
//windows style
ShowCursor(FALSE);
//hide mouse pointer
}
else
{
dwExStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;
//window extended style
dwStyle = WS_OVERLAPPEDWINDOW;
//windows style
}
AdjustWindowRectEx(&windowRect, dwStyle, FALSE, dwExStyle);
/* Class registerd, so now create our window*/
hwnd = CreateWindowEx(NULL,
"MyClass", //class name
"OpenGL Robot", //app name
dwStyle |
WS_CLIPCHILDREN |
WS_CLIPSIBLINGS,
0, 0,
//x and y coords
windowRect.right - windowRect.left,
windowRect.bottom - windowRect.top,
//width, height
NULL,
//handle to parent
NULL,
//handle to menu
hInstance,
//application instance
NULL);
//no xtra params
/* Check if window creation failed (hwnd = null ?)*/
if (!hwnd)
{
return 0;
}
ShowWindow(hwnd, SW_SHOW);
//display window
UpdateWindow(hwnd);
//update window
done =
false; //initialize loop condition variable
/* Main message loop*/
while (!done)
{
PeekMessage(&msg, hwnd, NULL, NULL, PM_REMOVE);
if (msg.message == WM_QUIT) //did we revieve a quit message?
{
done =
true;
}
else
{
Render();
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
if (fullScreen)
{
ChangeDisplaySettings(NULL, 0);
ShowCursor(TRUE);
}
return msg.wParam;
}
Thursday, March 08, 2007
Hoy es de esos dìas, en los que despierto y deseo ..you know...hacer un autómata que...:
sólo acepte tener 3 b´s. Conteniendo el alfabeto a,b.
la imagen rosita muestra esta automáta...
Además de esto, también desperté con ganas de hacer una autómata que sólo acepte palabras de longitud 6....
y pueees la imagen moradita es la que corresponde a esta otra automáta.
ah con que ganas despierta uno....
Tuesday, March 06, 2007
Speaking of which, I have a nifty picture of the robot that I have just recently made the code for...
I must say, that I have had a lot of problems building this figure...Because I didn`t use POP or PUSH!!! People pleeease read about what does glPushMatrix() and glPopMatrix() do ! It is sooo important!..it really caused me a lot of trouble. I went to bed very late last night, cuz I couldn`t finish the damn leg of this thing. It was really giving me a lot of trouble!..and all cuz I just couldn`t put myself upto reading more about how to do it correctly.
...Speaking of which...
tonight is also poems night.Specially tonight! why tonight, you might ask?...
Well, basically cuz I`ve been with my dear boy for 7 months now...and this calls for a poemy night with nice night poems:
Somewhere on the other side of this wide night
and the distance between us, I am thinking of you.
The room is turning slowly away from the moon.
This is pleasurable. Or shall I cross that out and say
it is sad? In one of the tenses I singing
an impossible song of desire that you cannot hear.
La lala la. See? I close my eyes and imagine
the dark hills I would have to cross
to reach you. For I am in love with you and this
is what it is like or what it is like in words...
Transformaciones Geometricas.
Una transformaciòn geomètrica permite eliminar la distorciòn geomètrica que pudiese existir cuando una imagen es capturada.
GL_PROJECTION: Es bàsicamnete una matriz de transformaciòn que se aplica a todos los puntos que vienen despuès de este comando. GL_MODELVIEW es una matriz de transformaciòn que se aplica a cada punto de un modelo en particular. Hay una jeraqruia entre las transformaciones , se tiene a GL_PROJECTION hasta arriba y se tienen como ramas a GL_MODEL .
Una transformaciòn geomètrica permite eliminar la distorciòn geomètrica que pudiese existir cuando una imagen es capturada.
· Traslación : Una traslaciòn simplemente mueve un objeto de un lugar a otro, al poner un ligero offset en X y en Y:
El segundo tipo de transformacion que existe se llama escalamiento. El escalamiento cambia el tamaño del objeto al multiplcar las coordenadas X y Y de un objeto por una constante de escalamiento.S
Figure 5: Scaling by Sx=2 Sy=2.
El ùltimo tipo de transformaciòn que veremos es la de rotacion. Puntos son rotados con respecto al origen un cierto àngulo.
Figure 6: Rotation around the origin.
Figure 7: Rotation of an object by 45 degrees.
Las tres transformaciones se llevan acabo al efectuar multiplicaciones entre matrices.
Las matrices con las que se multiplica a los vectores son respectivamente:
Figure 8: Formulas para translacion, escalamiento y rotaciòn.
Ahora bien OpenGl, nos brinda difernetes funciones para llevar acabo estas operaciones.
o Traslación (Translation)
glTranslatef( GLfloat x, GLfloat y, GLfloat z); en donde la función toma la medida de las variables x, y ,z para mover el objeto en sus ejes correspondientes dichas unidades.
o Escala (Scaling)
glScalef(GLfloat x , GLfloat y, Glfloat z); en donde cada uno de los parámetros mostrados indica la coordenada por la cual se multiplicará el valor real del objeto para posteriormente escalarlo a la medida deseada.
o Rotación
glRotatef(GLfloat angle, GLfloat x, GLfloat y, Glfloar z); en donde el parámetro se refiere a el ángulo que se desea rotar el objeto ; así tambien los tres subsecuentes especifican la rotaciòn a través de algun eje en especifico dando lugar asì al vector.
Charlando ahora de otro tema, entremos a ver que diablos esGL_PROJECTION: Es bàsicamnete una matriz de transformaciòn que se aplica a todos los puntos que vienen despuès de este comando. GL_MODELVIEW es una matriz de transformaciòn que se aplica a cada punto de un modelo en particular. Hay una jeraqruia entre las transformaciones , se tiene a GL_PROJECTION hasta arriba y se tienen como ramas a GL_MODEL .
Por ello, antes de realizar una operación de transformación es necesario indicar sobre que matriz se va a realizar. Se especifica con la función glMatrixMode(Glenum mode) que tiene como argumento una de las tres constantes enumeradas. Se comporta como un estado, por tanto, hasta que se especifique un nuevo estado todas las transformaciones se realizan sobre la última matriz especificada.
A continuaciòn mostrarè un còdigo para ejemplificar màs esto:
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1, 1, -1, 1, -1.0, 1.0);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1, 1, -1, 1, -1.0, 1.0);
glTranslate( 100, 100, 100 );
glRotateF( 45, 1, 0, 0 );
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslate( modelx, modely, modelz );
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1, 1, -1, 1, -1.0, 1.0);
glTranslate( camerax, cameray, cameraz );
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslate( carx, cary, carz );
// draw car here, by specifying various gl vertices
glLoadIdentity();
glTranslate( battleshipx, battleshipy, battleshipz );
// draw battleship here, by specifying various gl vertices
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1, 1, -1, 1, -1.0, 1.0);
glTranslate( camerax, cameray, cameraz );
glRotateF( cameraanglex, 1, 0, 0 );
¿ Què podemos concluir del còdigo anterior?
Es una MENTIRA QUE SE USA LA CAMARA, It is, because its pretty
obvious that we're really moving the entire world to get our picture,
and not some "camera"!!!
Ahora bien...ya que estamos chlando tan agusto, toquemos otro tema interesantòn:
En la función display() se encuentran las llamadas a dos funciones de matrices que todavía no han sido comentadas. Se trata de glPushMatrix() y glPopMatrix(). Para comprender su funcionamiento, primero se va a experimentar que es lo que ocurre cuando no están dichas llamadas. Para ello se comentan en la función display() ambas llamadas:
void display(void) {
...
// glPushMatrix();
...
glTranslatef(0.0, 0.0, .5);
...
// glPopMatrix();
glutSwapBuffers();
}
Al ejecutar de nuevo la aplicación, primeramente tiene el mismo aspecto que sin comentar las llamadas, pero si obligamos a que se llame varias veces a la función display(), por ejemplo pulsando la tecla “c” (que activa y desactiva los polígonos posteriores del objeto), vemos que además de producirse el efecto de cambiar el modo GL_CULL_FACE, el objeto se va moviendo progresivamente a lo largo de eje “Z”.
La razón de este movimiento es que en la función display está incluida una llamada a glTranslatef() que se utiliza para posicionar uno de los objetos. Como se ha explicado anteriormente, las funciones de traslación multiplican la matriz actual por una matriz de traslación creada con los argumentos que se le pasan, por tanto, sucesivas llamadas a la función display() provocan sucesivas multiplicaciones de la matriz actual con el efecto que se observa de incrementar la traslación.
Para solucionar este problema OpenGL dispone de unos stacks o pilas de matrices, que ermiten almacenar y recuperar una matriz anterior. Aunque OpenGL dispone de pilas para las matrices GL_MODELVIEW y GL_PROJECTION, sólo se suele utilizar la pila de GL_MODELVIEW. Una pila es un almacén con funcionamiento LIFO, el último en entrar es el primero en salir, por lo que suele comparar a una pila de platos en la que sólo se puede dejar uno encima de la pila o coger el superior que es el último depositado. La pila de matrices tiene el mismo funcionamiento sustituyendo los platos por matrices. La matriz superior de la pila es sobre la que se aplican las distintas transformaciones, multiplicándola por la matriz que generan las distintas funciones.
Para poder guardar una determinada matriz y posteriormente recuperarla OpenGLdispone de las dos funciones comentadas: glPushMatrix() y glPopMatrix().
La función glPushMatrix() realiza una copia de la matriz superior y la pone encima de la pila, de tal forma que las dos matrices superiores son iguales. En la figura 1 se observa la pila en la situación inicial con una sola matriz, al llamar a la función glPushMatrix() se duplica la matriz superior. Las siguientes transformaciones que se realizan se aplican sólo a la matriz superior de la pila, quedando la anterior con los valores que tenía en el momento de llamar a la función glPushMatrix().
La función glPopMatrix() elimina la matriz superior, quedando en la parte superior de
la pila la matriz que estaba en el momento de llamar a la función glPushMatrix().
En la función display() al llamar a la función glPushMatrix() se realiza una copia de la matriz actual. La traslación en el eje Z se realiza en la matriz superior de la pila, es decir, en la copia de la matriz, de tal forma que al llamar a la función glPopMatrix(), como se muestra en la figura 1, se elimina la matriz superior, que es la que tenía el efecto de esta transformación, quedando la matriz que estaba en el momento de llamar a glPushMatrix(). Al descomentar las llamadas a las funciones glPushMatrix() y glPopMatrix() las transformaciones realizadas entre ambas no afectan al resto de la aplicación.
Pues parece ser que ya mero estamos listos para entrar a programar en Opengl...But there is still something very important about OpenGl that you should know about:
Para crear cualquier figura geométrica en OpenGL hay que definir los vértices entre un par de llamadas a las funciones glBegin() y glEnd(). A la función glBegin se le puede pasar un argumento que determina qué tipo de figura geométrica se va construir. Después se definen los vértices mediante llamadas a la función glVertex. A ontinuación vemos un ejemplo en el que se define el polígono de la figura.
glBegin (GL_POLYGON);
glVertex2f (0.0, 0.0);
glVertex2f (0.0, 3.0);
glVertex2f (3.0, 3.0);
glVertex2f (4.0, 1.5);
glVertex2f (3.0, 0.0);
glEnd ();
void glBegin (GLenum mode);
void glEnd (void);
Marca el final de una lista de vértices.
Another yet interesting subject is of course: MODElADO gEOMETRICO!
Un modelo geometrico describe la figura de un objeto fisico o matematico uso de modelos geometricos. Los modelos Geometricos se suelen usar en computacion grafica,diseÑo procesamiento de imagenes medicas. Los modelos geometricos se pueden construir para objetos de cualquier modelados geometricos se distinguen justo en la dimension para la cual han sido construido. Tanto los modelos para dimensiones de 2D y 3D son usados mucho en computacion Los modelos geometricos se distinguinguen mucho de los modelos orientados implicitamente volumetricos, asi como con modelos matematicos implicitos como es el set de un polinomio arbitrario. Sin embargo, la distincion es en ocasiones un poco confusa, por ejemplo figuras geometricas pueden ser representadas por una imagen digital puede ser interpretada como una coleccion de cuadrados de colores, figuaras gèometricas, como peude ser un cìrculo, està definido por una ecuacion matematica implicita. Asimismo, el modelado de un
objeto fractal requiere de una combiancion de difernetes tipos de tecnicas.And since we are writing on into the night, let`s touch yet another matter:
glClearColor - Especifica valores para limpiar el buffer de color. Su especificacion esta dada por: void glClearColor( GLclampf red, GLclampf green, GLclampf blue,Glclampf alpha ) Los parámetros son: red, green, blue, alpha Especifica los valores rojo, verde, azul y alpha que son usados cuando el buffer de color es reseteado. Los valores iniciales son todos cero. Descripción: GLClearColor especifica los valores red, green, blue y alpha que serán usados por glClear para limpiar los colores del buffer. Los valores especificados por glClearColor están dentro del rango de [0,1]. glClear - Limpia los buffers para poner nuevos valores. C ESPECICACION:void glClear( GLbitfield mask ) PARAMETROS: mask Es una serie de Operaciones Bitwise de las masks que indican los buffers que deben ser vaciados. Las 4 mascaras son GL_COLOR_BUFFER_BIT,GL_DEPTH_BUFFER_BIT, GL_ACCUM_BUFFER_BIT, and GL_STENCIL_BUFFER_BIT.
DESCRIPCION: glClear pone en el área del bitplane los valores antes seccionados por el glClearColor, glClearIndex, glClearDepth,glClearStencil,y glClearAccum. Múltiples bufferS de color pueden ser limpiados simultáneamente al seleccionar mas de un buffer a la vez utilizando la herramienta de glDrawBuffer. glClear toma un solo argumento que es el resultante de la operación bitwise OR de diversos valores, este argumento indica cual de los buffers ha de ser limpiado. EJEMPLO DE CODIGO USANDO glClear y glClearColor #include
#include #include using namespace std; // function prototypes void disp(void); void keyb(unsigned char key, int x, int y); // window identifier static int win; int main(int argc, char **argv){ ////////// // INIT // ////////// // initialize glut glutInit(&argc, argv); // specify the display mode to be RGB and single buffering // we use single buffering since this will be non animated glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE); // define the size glutInitWindowSize(500,500); // the position where the window will appear glutInitWindowPosition(100,100); // if we would want fullscreen: // glutFullScreen(); // create the window, set the title and keep the // window identifier. win = glutCreateWindow("Yet another teapot"); ////////////// // CALLBACK // ////////////// glutDisplayFunc(disp); glutKeyboardFunc(keyb); //////////// // OPENGL // //////////// // define the color we use to clearscreen glClearColor(0.0,0.0,0.0,0.0); // enter the main loop glutMainLoop(); return 0; } void disp(void){ // do a clearscreen glClear(GL_COLOR_BUFFER_BIT); // draw something glutWireTeapot(0.5); // glutSolidTeapot(0.5); // glutWireSphere(0.5,100,100); // glutSolidSphere(0.5,100,100); // glutWireTorus(0.3,0.5,100,100); // glutSolidTorus(0.3,0.5,100,100); // glutWireIcosahedron(); // glutSolidIcosahedron(); // glutWireDodecahedron(); // glutSolidDodecahedron(); // glutWireCone(0.5,0.5,100,100); // glutSolidCone(0.5,0.5,100,100); // glutWireCube(0.5); // glutSolidCube(0.5); } void keyb(unsigned char key, int x, int y){ cout << "Pressed key " <<> ")"; cout <<> if(key == 'q'){ cout << "Got q,so quitting " <<> glutDestroyWindow(win);
exit(0); } 9) glutInit glutInit es utilizada para inicializar la librería de GLUT. Se usa de la siguiente forma: void glutInit(int *argcp, char **argv); argcp: es un apuntador a la variable argc del main. argv: la variable argv sin modificar del main. Descripción:glutInit inicializara la librería GLUT y negociara una sesión con la ventana del sistema . glutInitDisplayMode: Asigna el modo de display inicial. Se utiliza de la siguiente forma: void glutInitDisplayMode(unsigned int mode); mode: Es el modo de display. Algunos ejemplos son: GLUT_RGBA: Mascara bit para seleccionar una ventana de modo RBGA. GLUT_STEREO: Mascara de bit para seleccionar una ventana de tipo stereo. glutInitWindowPosition pone el valor inicial de la ventana . La sintaxis para su uso es: glutInitWindowPosition(x,y) x, y: localización de la ventana en pixeles. glutInitWindowSize — Pone el tamaño de la ventana inicial. glutInitWindowSize(width,height) glutCreateWindow (): Crea una ventana de nivel superior. La sintaxis es: int glutCreateWindow(char *name)
glutDisplayFunc(): Fija el callback del display para la ventana en cuestion.Se utiliza de la siguiente forma: void glutDisplayFunc(void (*func)(void)); func es la nueva funcion de callback. Cuando GLUT determina que el plano normal de la ventan necesita volverse a desplejar, el display callback para la ventana es llamado. glutReshapeFunc() pone el callback de la redefinicion del tamanio para la ventana en cuestion. void glutReshapeFunc(void (*func)(int width, int height)); func: es la nueva funcion reshape callback El reshape callback es llamado cuando se cambia el tamanio de la ventana. glutKeyboardFunc(): Pone el callback del teclado para la ventana actual. void glutKeyboardFunc(void (*func)(unsigned char key,int x, int y)); func: es la nueva funcion teclado callback glutMainLoop() mete el loop del evento de procesameinto de GLUT. Una vez que es llamada esta rutina nunca retornara Hemos estado usando mucho la palabra callback aquì...but what the f* es un callback?
Callback: Se dice que existe un callback, cuando ocurre un cierto evento y uno programa la respuesta que dará el programa. Uno define que función será llamada (called) cuando sucede un evento. Ahora bien, Glut tiene una serie de callbacks bien definidas. ejemplo: void glutDisplayFunc(void (*func)(void)); Esto especifica la función que necesita ser llamada cuando se redibuja la ventana
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