#146267 - speedemon35 - Sat Dec 01, 2007 7:04 pm
hy to all of you again. I got some quite helpful feedback here last time i think i'll give gba programming a second shot.
Anyway. My new task consists of a few things: drawing a line(segment to be more precise since it can't take up all the width of height of the screen), drawing a circle, making them move about and have the option of the user pressing 1 key so he can alter between circle and line.
I've managed to fix up the code for drawing 1 single line. I've also managed in a separate code to draw the circle. But for now my biggest problem is getting them to move around. I figured if i can get the line to move first then it will be almost the same thing to make the circle move so i'll focus only on the line for now. I added in the check buttons thing and all that with the while{1} loop but for some reason its not working properly. Either i'm using the wrong variables inside the loop, or i need to place more variables inside it or my while loop is simply in the wrong place and its doing nothing what so ever:(
the code is here:
i've tried changing the variables inside the while loop a couple of times already but none of them worked correctly so i just left them at my last attempt to make them work.
I have a pretty good idea on how i need to go about letting the user change between circle and line since it should simply follow the same logic as changing a pixels color each time 1 key was pressed. Right now my concern is getting that line to move around.
Again thank you for your time.
Sincerely,
Daniel Mendes.
Anyway. My new task consists of a few things: drawing a line(segment to be more precise since it can't take up all the width of height of the screen), drawing a circle, making them move about and have the option of the user pressing 1 key so he can alter between circle and line.
I've managed to fix up the code for drawing 1 single line. I've also managed in a separate code to draw the circle. But for now my biggest problem is getting them to move around. I figured if i can get the line to move first then it will be almost the same thing to make the circle move so i'll focus only on the line for now. I added in the check buttons thing and all that with the while{1} loop but for some reason its not working properly. Either i'm using the wrong variables inside the loop, or i need to place more variables inside it or my while loop is simply in the wrong place and its doing nothing what so ever:(
the code is here:
| Code: |
|
#define MULTIBOOT int __gba_multiboot; MULTIBOOT #include <stdlib.h> //declare the function prototype void DrawPixel3(int, int, unsigned short); void DrawLine3(int, int, int, int, unsigned short); //declare some defines for the video mode #define ScreenWidth 240 #define ScreenHeight 160 #define REG_DISPCNT *(unsigned long*)0x4000000 #define MODE_3 0x3 #define BG2_ENABLE 0x400 //changes the video mode #define SetMode(mode) REG_DISPCNT = (mode) //packs three values into a 15-bit color #define RGB(r,g,b) ((r)+(g<<5)+(b<<10)) //Key Definitions from Nokturn's key demo #define KEY_A 1 #define KEY_B 2 #define KEY_SELECT 4 #define KEY_START 8 #define KEY_RIGHT 16 #define KEY_LEFT 32 #define KEY_UP 64 #define KEY_DOWN 128 #define KEY_R 256 #define KEY_L 512 //create a pointer to the video buffer unsigned short* videoBuffer = (unsigned short*)0x6000000; volatile int* KEYS = (volatile int*)0x04000130; short col[14]; bool buttons[10]; // Function: main() int main(void) { int x1,y1,x2,y2; unsigned short color; SetMode(MODE_3 | BG2_ENABLE); while(1) { x1 = 100; y1 = 80; x2 = 140; y2 = 80; color = RGB(31,31,0); DrawLine3(x1,y1,x2,y2,color); } return 0; } void clearscreen() { int x, y; unsigned short black= RGB(0,0,0); for ( x = 0; x < (ScreenWidth); x+=1) { for ( y = 0; y < (ScreenHeight); y+=1) {DrawPixel3(x,y,black);} } } void checkbuttons() { buttons[0] = !((*KEYS) & KEY_A); buttons[1] = !((*KEYS) & KEY_B); buttons[2] = !((*KEYS) & KEY_UP); buttons[3] = !((*KEYS) & KEY_DOWN); buttons[4] = !((*KEYS) & KEY_LEFT); buttons[5] = !((*KEYS) & KEY_RIGHT); buttons[6] = !((*KEYS) & KEY_START); buttons[7] = !((*KEYS) & KEY_SELECT); buttons[8] = !((*KEYS) & KEY_L); buttons[9] = !((*KEYS) & KEY_R); } // Function: DrawPixel3 void DrawPixel3(int x, int y, unsigned short color) { videoBuffer[y * 240 + x] = color; } // Function: DrawLine3 void DrawLine3(int x1, int y1, int x2, int y2, unsigned short color) { int i, deltax, deltay, numpixels; int d, dinc1, dinc2; int x, xinc1, xinc2; int y, yinc1, yinc2; //calculate deltaX and deltaY deltax = abs(x2 - x1); deltay = abs(y2 - y1); //initialize if(deltax >= deltay) { //If x is independent variable numpixels = deltax + 1; d = (2 * deltay) - deltax; dinc1 = deltay << 1; dinc2 = (deltay - deltax) << 1; xinc1 = 1; xinc2 = 1; yinc1 = 0; yinc2 = 1; } else { //if y is independent variable numpixels = deltay + 1; d = (2 * deltax) - deltay; dinc1 = deltax << 1; dinc2 = (deltax - deltay) << 1; xinc1 = 0; xinc2 = 1; yinc1 = 1; yinc2 = 1; } //move the right direction if(x1 > x2) { xinc1 = -xinc1; xinc2 = -xinc2; } if(y1 > y2) { yinc1 = -yinc1; yinc2 = -yinc2; } x = x1; y = y1; //draw the pixels for(i = 1; i < numpixels; i++) { DrawPixel3(x, y, color); if(d < 0) { d = d + dinc1; x = x + xinc1; y = y + yinc1; } else { d = d + dinc2; x = x + xinc2; y = y + yinc2; while(1) { checkbuttons(); if (buttons[2]) { if (y > 0)//up {clearscreen(); y = deltay - 1; DrawLine3(x1,y1,x2,y2,color);} } if (buttons[3])//down { if (y < (ScreenHeight - 1)) {clearscreen(); y = deltay + 1; DrawLine3(x1,y1,x2,y2,color);} } if (buttons[4]) { if ( x > 0 )//left {clearscreen(); x = deltax - 1; DrawLine3(x1,y1,x2,y2,color);} } if (buttons[5])//right { if ( x < (ScreenWidth - 1)) {clearscreen(); x = deltax + 1; DrawLine3(x1,y1,x2,y2,color);} } } } } } |
i've tried changing the variables inside the while loop a couple of times already but none of them worked correctly so i just left them at my last attempt to make them work.
I have a pretty good idea on how i need to go about letting the user change between circle and line since it should simply follow the same logic as changing a pixels color each time 1 key was pressed. Right now my concern is getting that line to move around.
Again thank you for your time.
Sincerely,
Daniel Mendes.