Graphics/3D/nehe/lesson08/source/nehe8.cpp

/****************************************
 *              NDS NeHe Lesson 08                      *
 *              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();


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);
        
        glEnable(GL_BLEND);
        
        // 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 ligth arguments are light number (0-3), light color, 
        //and an x,y,z vector that points in the direction of the light
        glLight(0, RGB15(31,31,31) , 0, floattov10(-1.0), 0);

        glColor3f(1,1,1);
        
        glMatrixMode(GL_MODELVIEW);
        
        //need to set up some material properties since DS does not have them set by default
        
        glMaterialf(GL_AMBIENT, RGB15(16,16,16));
        glMaterialf(GL_DIFFUSE, RGB15(16,16,16));
        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 (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;
                }

                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);
        
        glPolyFmt(POLY_ALPHA(31) | POLY_CULL_NONE  | POLY_FORMAT_LIGHT0);

        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);
        glEnd();

        glPolyFmt(POLY_ALPHA(15) | POLY_CULL_BACK  | POLY_FORMAT_LIGHT0);
        
        glBegin(GL_QUADS);
        
        // 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

}