Constants...?

[gamebuster]

I'm busy editing a DirectX code to create a game. I'm a beginner, so the source code may and will be messy, but that doesn't matter for now.

I'm fighting against something i think is really weird:

The code:

// include the basic windows header files and the Direct3D header file
#include <windows.h>
#include <windowsx.h>
#include <time.h>
#include <d3d9.h>
#include <d3dx9.h>

// define the screen resolution and keyboard macros
#define SCREEN_WIDTH  640
#define SCREEN_HEIGHT 480
#define KEY_DOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEY_UP(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 0 : 1)

// include the Direct3D Library file
#pragma comment (lib, "d3d9.lib")
#pragma comment (lib, "d3dx9.lib")

// global declarations
LPDIRECT3D9 d3d;    // the pointer to our Direct3D interface
LPDIRECT3DDEVICE9 d3ddev;    // the pointer to the device class
LPD3DXSPRITE d3dspt;    // the pointer to our Direct3D Sprite interface

// sprite declarations
LPDIRECT3DTEXTURE9 sprite[7];    // the pointer to the sprite

// function prototypes
void initD3D(HWND hWnd); // sets up and initializes Direct3D
void render_frame(void); // renders a single frame
void initField(void);
void cleanD3D(void); // closes Direct3D and releases memory

// the WindowProc function prototype
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);


// the entry point for any Windows program
[deleted to lack of space]


// this is the main message handler for the program
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch(message)
    {
        case WM_DESTROY:
            {
                PostQuitMessage(0);
                return 0;
            } break;
    }

    return DefWindowProc (hWnd, message, wParam, lParam);
}


// this function initializes and prepares Direct3D for use
void initD3D(HWND hWnd)
{
    d3d = Direct3DCreate9(D3D_SDK_VERSION);

    D3DPRESENT_PARAMETERS d3dpp;

    ZeroMemory(&d3dpp, sizeof(d3dpp));
    d3dpp.Windowed = FALSE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.hDeviceWindow = hWnd;
    d3dpp.BackBufferFormat = D3DFMT_X8R8G8B8;
    d3dpp.BackBufferWidth = SCREEN_WIDTH;
    d3dpp.BackBufferHeight = SCREEN_HEIGHT;


    // create a device class using this information and the info from the d3dpp stuct
    d3d->CreateDevice(D3DADAPTER_DEFAULT,
                      D3DDEVTYPE_HAL,
                      hWnd,
                      D3DCREATE_SOFTWARE_VERTEXPROCESSING,
                      &d3dpp,
                      &d3ddev);

    D3DXCreateSprite(d3ddev, &d3dspt);    // create the Direct3D Sprite object

	D3DXCreateTextureFromFile(d3ddev, L"c:\\pdp\\blue.png", &sprite[0]);
	D3DXCreateTextureFromFile(d3ddev, L"c:\\pdp\\cyan.png", &sprite[1]);
	D3DXCreateTextureFromFile(d3ddev, L"c:\\pdp\\green.png", &sprite[2]);
	D3DXCreateTextureFromFile(d3ddev, L"c:\\pdp\\pink.png", &sprite[3]);
	D3DXCreateTextureFromFile(d3ddev, L"c:\\pdp\\red.png", &sprite[4]);
	D3DXCreateTextureFromFile(d3ddev, L"c:\\pdp\\yellow.png", &sprite[5]);
	D3DXCreateTextureFromFile(d3ddev, L"c:\\pdp\\yellow.png", &sprite[6]);//METAL should be here!
	D3DXCreateTextureFromFile(d3ddev, L"c:\\pdp\\back.png", &sprite[7]);

    return;
}

unsigned char Yoffset[2];//vertical offset. (pixels) 0-32, used for the spawning blocks in bottom.
int YabsoluteOffset[2];//Absolute vertical offset. (pixels)
unsigned char chainpointer[254];//variable containing the chain values.
unsigned short fieldsettings[5] = {
	1, //count of fields, 1 or 2
	80, //X of top left position of field 1
	62, //Y of top left position of field 1
	368, //X of top left position of field 2
	62, //Y of top left position of field 2
};
unsigned char field[2][255][7];

void initField(void) {
	//clear and reset all field variables.
	char Xsprite = 0;
	char Xpos = 0;
	char Ypos = 0;
	for(unsigned char x = 0;x < 2;x++) {
		for(unsigned char y = 0;y < 255;y++) {
			for(unsigned char z = 0;z < 7;z++) {
				field[x][y][z] = 0;
			}
			field[x][y][0]=Xsprite;Xsprite++;if(Xsprite>5){Xsprite=0;}
			
		}
	}
	//clear and reset all chain pointers
	for(unsigned char x = 0;x < 254;x++) {
		chainpointer[x] = 0;
	}
}

// this is the function used to render a single frame
void render_frame(void)
{
    // clear the window to a deep blue
    d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, 0xff222222, 1.0f, 0);
    d3ddev->BeginScene();    // begins the 3D scene
    d3dspt->Begin(NULL);    // begin sprite drawing
    // set center @ upper-left.
    D3DXVECTOR3 center(0.0f, 0.0f, 0.0f);    // center at the upper-left corner

    D3DXVECTOR3 position(64.0f, -16.0f, 0.0f);
    d3dspt->Draw(sprite[7], NULL, &center, &position, 0xffffffff);

    D3DXVECTOR3 position(fieldsettings[1], fieldsettings[2], 0.0f);
    d3dspt->Draw(sprite[0], NULL, &center, &position, 0xffffffff);
    D3DXVECTOR3 position(fieldsettings[3], fieldsettings[4], 0.0f);
    d3dspt->Draw(sprite[0], NULL, &center, &position, 0xffffffff);

    d3dspt->End();    // end sprite drawing
    d3ddev->EndScene();    // ends the 3D scene
    d3ddev->Present(NULL, NULL, NULL, NULL);

    return;
}


// this is the function that cleans up Direct3D and COM
void cleanD3D(void)
{
	for(unsigned char i = 0;i < 6;i++) {
	 sprite[i]->Release();		
	}
    d3ddev->Release();
    d3d->Release();

    return;
}

When i compile this, i get some errors:

1 2 3 4 5 6 7 8 9

1

1>Compiling... 1>main.cpp 1>.\main.cpp(232) : error C2374: 'position' : redefinition; multiple initialization 1> .\main.cpp(229) : see declaration of 'position' 1>.\main.cpp(234) : error C2374: 'position' : redefinition; multiple initialization 1> .\main.cpp(229) : see declaration of 'position' 1>Build log was saved at "file://c:\Users\toby_hinloopen\Documents\Visual Studio 2008\Projects\project4\project4\Release\BuildLog.htm" 1>project4 - 2 error(s), 0 warning(s) ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Its clear: the compiler doesn't like to have a constant redeclared... but what should i do? I can't define 10000 constants because i can't edit them?

The only thing i want is "position" to be dynamicly changed.

How is this possible?
Is there a way to unset constants?

btw, if i try something like this:

    //D3DXVECTOR3 position(64.0f, -16.0f, 0.0f);
    d3dspt->Draw(sprite[7], NULL, &center, D3DXVECTOR3(64.0f, -16.0f, 0.0f), 0xffffffff);

    //D3DXVECTOR3 position(fieldsettings[1], fieldsettings[2], 0.0f);
    d3dspt->Draw(sprite[0], NULL, &center, D3DXVECTOR3(fieldsettings[1], fieldsettings[2], 0.0f), 0xffffffff);
    //D3DXVECTOR3 position(fieldsettings[3], fieldsettings[4], 0.0f);
    d3dspt->Draw(sprite[0], NULL, &center, D3DXVECTOR3(fieldsettings[3], fieldsettings[4], 0.0f), 0xffffffff);

I get errors like this:

1 2 3 4 5 6 7 8 9 10 11

1

1>Compiling... 1>main.cpp 1>.\main.cpp(230) : error C2664: 'ID3DXSprite::Draw' : cannot convert parameter 4 from 'D3DXVECTOR3' to 'const D3DXVECTOR3 *' 1> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called 1>.\main.cpp(233) : error C2664: 'ID3DXSprite::Draw' : cannot convert parameter 4 from 'D3DXVECTOR3' to 'const D3DXVECTOR3 *' 1> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called 1>.\main.cpp(235) : error C2664: 'ID3DXSprite::Draw' : cannot convert parameter 4 from 'D3DXVECTOR3' to 'const D3DXVECTOR3 *' 1> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called 1>Build log was saved at "file://c:\Users\toby_hinloopen\Documents\Visual Studio 2008\Projects\project4\project4\Release\BuildLog.htm" 1>project4 - 3 error(s), 0 warning(s) ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

EDIT:
... after trying and trying, i fixed it using:

    //D3DXVECTOR3 position(64.0f, -16.0f, 0.0f);
    d3dspt->Draw(sprite[7], NULL, &center, &D3DXVECTOR3(64.0f, -16.0f, 0.0f), 0xffffffff);

    //D3DXVECTOR3 position(fieldsettings[1], fieldsettings[2], 0.0f);
    d3dspt->Draw(sprite[0], NULL, &center, &D3DXVECTOR3(fieldsettings[1], fieldsettings[2], 0.0f), 0xffffffff);
    //D3DXVECTOR3 position(fieldsettings[3], fieldsettings[4], 0.0f);
    d3dspt->Draw(sprite[0], NULL, &center, &D3DXVECTOR3(fieldsettings[3], fieldsettings[4], 0.0f), 0xffffffff);

just a & sign was required... -.-"
great, those clear errors :P

>>> THIS PROBLEM IS SOLVED <<<
tnx for the... *kuch* replies :P

[Zaita]

You've declared multiple variables with the same name in the function called position.

    D3DXVECTOR3 position(64.0f, -16.0f, 0.0f);
    d3dspt->Draw(sprite[7], NULL, &center, &position, 0xffffffff);

    position(fieldsettings[1], fieldsettings[2], 0.0f);
    d3dspt->Draw(sprite[0], NULL, &center, &position, 0xffffffff);
    position(fieldsettings[3], fieldsettings[4], 0.0f);
    d3dspt->Draw(sprite[0], NULL, &center, &position, 0xffffffff);

Should work.

[Dacster13]

Its clear: the compiler doesn't like to have a constant redeclared... but what should i do? I can't define 10000 constants because i can't edit them?

the reason you can't redeclare a constant is because it's supposed to be constant, meaning the value is constant, never changes, and will never be changed. You shouldn't be changing the value if it's a constant. You wouldn't expect a constant named PI to change from 3.1416 to something like 1.0384

use a variable if you want to change the value. :P