Graphics/3D/BoxTest/source/main.cpp

/*---------------------------------------------------------------------------------
    
    Box test to demonstrate 3D bounding box es.  also shows the effect of culling and
    clipping on vertex usage
*--------------------------------------------------------------------------------*/


#include <nds.h>

#include <stdio.h>



//some code for profiling
//---------------------------------------------------------------------------------
u16 startTimer(int timer) {
//---------------------------------------------------------------------------------

    TIMER_CR(timer) = 0;
    TIMER_DATA(0) = 0;
    TIMER_CR(timer) = TIMER_DIV_1 | TIMER_ENABLE;
    return TIMER_DATA(0);
}

#define getTimer(timer) (TIMER_DATA(timer))

//---------------------------------------------------------------------------------
//draws a box...same signature as boxTest
//---------------------------------------------------------------------------------
void DrawBox(float x, float y, float z, float width, float height, float depth) {
//---------------------------------------------------------------------------------
    glBegin(GL_QUADS);
    //z  face
    glColor3f(1,0,0);
    glVertex3f(x , y , z );
    glVertex3f(x + width, y , z );
    glVertex3f(x + width, y + height, z );
    glVertex3f(x , y + height, z );

    //z + depth face
    glColor3f(1,0,1);
    glVertex3f(x , y , z + depth);
    glVertex3f(x , y + height, z + depth);
    glVertex3f(x + width, y + height, z + depth);
    glVertex3f(x + width, y , z + depth);


    //x  face
    glColor3f(1,1,0);
    glVertex3f(x , y , z );
    glVertex3f(x , y + height, z );
    glVertex3f(x , y + height, z + depth);
    glVertex3f(x , y , z + depth);

    //x + width face
    glColor3f(1,1,1);
    glVertex3f(x + width, y , z );
    glVertex3f(x + width, y , z + depth);
    glVertex3f(x + width, y + height, z + depth);
    glVertex3f(x + width, y + height, z );

    //y  face
    glColor3f(0,1,0);
    glVertex3f(x , y , z );
    glVertex3f(x , y , z + depth);
    glVertex3f(x + width, y , z + depth);
    glVertex3f(x + width, y , z );

    //y  + height face
    glColor3f(0,1,1);
    glVertex3f(x , y + height, z );
    glVertex3f(x + width, y + height, z );
    glVertex3f(x + width, y + height, z + depth);
    glVertex3f(x , y + height, z + depth);

    glEnd();

}

//---------------------------------------------------------------------------------
int main() {    
//---------------------------------------------------------------------------------

    touchPosition touchXY;

    //put 3D on top
    lcdMainOnTop();

    //setup the sub screen for basic printing
    consoleDemoInit();

    // Setup the Main screen for 3D 
    videoSetMode(MODE_0_3D);

    // initialize gl
    glInit();
    
    // enable antialiasing
    glEnable(GL_ANTIALIAS);
    
    // setup the rear plane
    glClearColor(0,0,0,31); // BG must be opaque for AA to work
    glClearPolyID(63); // BG must have a unique polygon ID for AA to work
    glClearDepth(0x7FFF);
    
    // Set our view port to be the same size as the screen
    glViewport(0,0,255,191);
    
    //camera
    float rotX = 0, rotY = 0;
    float translate = -5;

    //some profiling code
    u16 time;

    //keep track of vertex ram usage
    int polygon_count;
    int vertex_count;

    //object 
    int rx = 50, ry = 15;
    int oldx = 0, oldy = 0;


    printf("\x1b[10;0HPress A to change culling");
    printf("\n\nPress B to change Ortho vs Persp");
    printf("\nLeft/Right/Up/Down to rotate");
    printf("\nPress L and R to zoom");
    printf("\nTouch screen to rotate cube");

    //main loop
    while (1) {

        //process input
        scanKeys();

        touchRead(&touchXY);

        
        int held = keysHeld();
        int pressed = keysDown();
        
        if( held & KEY_LEFT) rotY++;
        if( held & KEY_RIGHT) rotY--;
        if( held & KEY_UP) rotX ++;
        if( held & KEY_DOWN) rotX --;
        if( held & KEY_L) translate += .1;
        if( held & KEY_R) translate -= .1;

        //reset x and y when user touches screen
        if( pressed & KEY_TOUCH)  {
            oldx = touchXY.px;
            oldy = touchXY.py;
        }

        //if user drags then grab the delta
        if( held & KEY_TOUCH) {
            rx += touchXY.px - oldx; 
            ry += touchXY.py - oldy;
            oldx = touchXY.px;
            oldy = touchXY.py;
        }

        
        //change ortho vs perspective
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        if(keysHeld() & KEY_B)
            glOrtho(-4,4,-3,3,0.1,10);  
        else {
            gluPerspective(70, 256.0 / 192.0, 0.1, 10);
        }
        //change cull mode
        if( held & KEY_A)
            glPolyFmt(POLY_ALPHA(31) | POLY_CULL_NONE );
        else
            glPolyFmt(POLY_ALPHA(31) | POLY_CULL_FRONT );

        // Set the current matrix to be the model matrix
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();

        //handle camera
        glRotateY(rotY);
        glRotateX(rotX);
        glTranslatef(0,0,translate);

        //move the cube
        glRotateX(ry);
        glRotateY(rx);

        DrawBox(-1,-1,-1,2,2,2);

        swiWaitForVBlank();
        printf("\x1b[0;0HBox test cycle count");

        time = startTimer(0);
        int hit = BoxTestf(-1,-1,-1,2,2,2);
        printf("\nSingle test (float): %i", 2*(getTimer(0) - time));

        time = startTimer(0);
        BoxTest(inttov16(-1),inttov16(-1),inttov16(-1),inttov16(2),inttov16(2),inttov16(2));
        printf("\nSingle test (fixed): %i", 2*(getTimer(0) - time));

        time = startTimer(0);
        for(int i = 0; i < 64; i++)
            BoxTest(inttov16(-1),inttov16(-1),inttov16(-1),inttov16(2),inttov16(2),inttov16(2));

        printf("\n64 tests avg. (fixed): %i", (getTimer(0) - time) / 32);
        printf("\nBox Test result: %s", hit ? "hit" : "miss");

        while (GFX_STATUS & (1<<27)); // wait until the geometry engine is not busy

        glGetInt(GL_GET_VERTEX_RAM_COUNT, &vertex_count);
        glGetInt(GL_GET_POLYGON_RAM_COUNT, &polygon_count);

        printf("\n\nRam usage: Culling %s", ( held & KEY_A) ? "none" : "back faces" );
        printf("\nVertex ram: %i", vertex_count);
        printf("\nPolygon ram: %i", polygon_count);

        // flush to the screen
        glFlush(0);

    }

    return 0;
}