Graphics/3D/nehe/lesson07/source/nehe7.cpp

/****************************************
 *      NDS NeHe Lesson 07              *
 *      Author: Ethos                   *
 ****************************************/

// include your ndslib
#include <nds.h>
#include <malloc.h>
//needed to load pcx files
#include <nds/arm9/image.h>


#include "drunkenlogo_pcx.h"

int DrawGLScene();
bool    light;              // Lighting ON/OFF ( NEW )
bool    lp;                 // L Pressed? ( NEW )

float   xrot;               // X Rotation
float   yrot;               // Y Rotation
float xspeed;               // X Rotation Speed
float yspeed;               // Y Rotation Speed
float   z=-5.0f;            // Depth Into The Screen

float LightAmbient[]=       { 0.5f, 0.5f, 0.5f, 1.0f };
float LightDiffuse[]=       { 1.0f, 1.0f, 1.0f, 1.0f };
float LightPosition[]=  { 0.0f, 0.0f, 2.0f, 1.0f };

int texture[3];         // Storage For 3 Textures (only going to use 1 on the DS for this demo)



int LoadGLTextures()                                    // Load PCX files And Convert To Textures
{
    sImage pcx;                

    //load our texture
    loadPCX((u8*)drunkenlogo_pcx, &pcx);
    image8to16(&pcx);

    //DS supports no filtering of anykind so no need for more than one texture
    glGenTextures(1, &texture[0]);
    glBindTexture(0, texture[0]);
    glTexImage2D(0, 0, GL_RGB, TEXTURE_SIZE_128 , TEXTURE_SIZE_128, 0, TEXGEN_TEXCOORD, pcx.image.data8);

    imageDestroy(&pcx);

    return TRUE;
}

int main() {
    // Setup the Main screen for 3D 
    videoSetMode(MODE_0_3D);
    vramSetBankA(VRAM_A_TEXTURE);                        //NEW  must set up some memory for textures
    
    // initialize the geometry engine
    glInit();
    
    // enable textures
    glEnable(GL_TEXTURE_2D);
    
    // 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 viewport to be the same size as the screen
    glViewport(0,0,255,191);
    
    LoadGLTextures();
    
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(70, 256.0 / 192.0, 0.1, 100);
    
    //set up a directional light arguments are light number (0-3), light color, 
    //and an x,y,z vector that points in the direction of the light, the direction must be normalized
    glLight(0, RGB15(31,31,31) , 0, floattov10(-1.0), 0);
    
    //need to set up some material properties since DS does not have them set by default
    glMaterialf(GL_AMBIENT, RGB15(8,8,8));
    glMaterialf(GL_DIFFUSE, RGB15(8,8,8));
    glMaterialf(GL_SPECULAR, BIT(15) | RGB15(8,8,8));
    glMaterialf(GL_EMISSION, RGB15(16,16,16));
    
    //ds uses a table for shinyness..this generates a half-ass one
    glMaterialShinyness();
    
    // Set the current matrix to be the model matrix
    glMatrixMode(GL_MODELVIEW);
    
    while (1) 
    {
        //these little button functions are pretty handy
        scanKeys();

    
        if ((keysDown() & KEY_A)) light = !light;
        if (keysHeld() & KEY_R) z-=0.02f;
        if (keysHeld() & KEY_L) z+=0.02f;
        if (keysHeld() & KEY_LEFT) xspeed-=0.01f;
        if (keysHeld() & KEY_RIGHT) xspeed+=0.01f;
        if (keysHeld() & KEY_UP) yspeed+=0.01f;
        if (keysHeld() & KEY_DOWN) yspeed-=0.01f;
        
        
        glColor3f(1,1,1);
        
        if (!light)
        {
            //ds specific, several attributes can be set here including turning on our light    
            glPolyFmt(POLY_ALPHA(31) | POLY_CULL_BACK);
        }
        else
        {
            //ds specific, several attributes can be set here including turning on our light    
            glPolyFmt(POLY_ALPHA(31) | POLY_CULL_BACK  | POLY_FORMAT_LIGHT0);
        }

        DrawGLScene();

        // flush to screen  
        glFlush(0);
        
        // wait for the screen to refresh
        swiWaitForVBlank();
    }
    
    return 0;
}

int DrawGLScene()                                           // Here's Where We Do All The Drawing
{
    glLoadIdentity();                                   // Reset The View
    glTranslatef(0.0f,0.0f,z);

    glRotatef(xrot,1.0f,0.0f,0.0f);
    glRotatef(yrot,0.0f,1.0f,0.0f);

    glBindTexture(GL_TEXTURE_2D, texture[0]);  //no filters to swtich between

    glBegin(GL_QUADS);
        // Front Face
        glNormal3f( 0.0f, 0.0f, 1.0f);
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
        // Back Face
        glNormal3f( 0.0f, 0.0f,-1.0f);
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
        // Top Face
        glNormal3f( 0.0f, 1.0f, 0.0f);
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
        // Bottom Face
        glNormal3f( 0.0f,-1.0f, 0.0f);
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
        // Right face
        glNormal3f( 1.0f, 0.0f, 0.0f);
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
        // Left Face
        glNormal3f(-1.0f, 0.0f, 0.0f);
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
    glEnd();

    xrot+=xspeed;
    yrot+=yspeed;
    return TRUE;                                        // Keep Going

}