GLdc/samples/nehe08/main.c

/*
   KallistiOS 2.0.0

   nehe08.c
   (c)2021 Luke Benstead
   (c)2014 Josh Pearson
   (c)2001 Benoit Miller
   (c)2000 Jeff Molofee
*/

#ifdef __DREAMCAST__
#include <kos.h>
#endif

#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glkos.h>

/* Simple OpenGL example to demonstrate blending and lighting.

   Essentially the same thing as NeHe's lesson08 code.
   To learn more, go to http://nehe.gamedev.net/.

   DPAD controls the cube rotation, button A & B control the depth
   of the cube, button X toggles filtering, and button Y toggles alpha
   blending.
*/

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

static GLuint filter;       /* Which Filter To Use */
static GLuint texture[2];   /* Storage For Two Textures */

/* Load a PVR texture - located in pvr-texture.c */
extern GLuint glTextureLoadPVR(char *fname, unsigned char isMipMapped, unsigned char glMipMap);

void draw_gl(void) {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();
    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[filter]);

    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;
}

#ifdef __DREAMCAST__
extern uint8 romdisk[];
KOS_INIT_ROMDISK(romdisk);
#endif

int main(int argc, char **argv) {
#ifdef __DREAMCAST__
    maple_device_t *cont;
    cont_state_t *state;
#endif

    GLboolean xp = GL_FALSE;
    GLboolean yp = GL_FALSE;
    GLboolean blend = GL_FALSE;

    printf("nehe08 beginning\n");

    /* Get basic stuff initialized */
    glKosInit();

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0f, 640.0f / 480.0f, 0.1f, 100.0f);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glEnable(GL_TEXTURE_2D);
    glShadeModel(GL_SMOOTH);
    glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
    glClearDepth(1.0f);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);

    glColor4f(1.0f, 1.0f, 1.0f, 0.5);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE);

    /* Enable Lighting and GL_LIGHT0 */
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);

    /* Set up the textures */
    texture[0] = glTextureLoadPVR("/rd/glass.pvr", 0, 0);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    texture[1] = glTextureLoadPVR("/rd/glass.pvr", 0, 0);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    while(1) {
#ifdef __DREAMCAST__
        cont = maple_enum_type(0, MAPLE_FUNC_CONTROLLER);

        /* Check key status */
        state = (cont_state_t *)maple_dev_status(cont);

        if(!state) {
            printf("Error reading controller\n");
            break;
        }

        if(state->buttons & CONT_START)
            break;

        if(state->buttons & CONT_A)
            z -= 0.02f;

        if(state->buttons & CONT_B)
            z += 0.02f;

        if((state->buttons & CONT_X) && !xp) {
            xp = GL_TRUE;
            filter += 1;

            if(filter > 1)
                filter = 0;
        }

        if(!(state->buttons & CONT_X))
            xp = GL_FALSE;

        if((state->buttons & CONT_Y) && !yp) {
            yp = GL_TRUE;
            blend = !blend;
        }

        if(!(state->buttons & CONT_Y))
            yp = GL_FALSE;

        if(state->buttons & CONT_DPAD_UP)
            xspeed -= 0.01f;

        if(state->buttons & CONT_DPAD_DOWN)
            xspeed += 0.01f;

        if(state->buttons & CONT_DPAD_LEFT)
            yspeed -= 0.01f;

        if(state->buttons & CONT_DPAD_RIGHT)
            yspeed += 0.01f;
#endif

        /* Switch to the blended polygon list if needed */
        if(blend) {
            glEnable(GL_BLEND);
            glDepthMask(0);
        }
        else {
            glDisable(GL_BLEND);
            glDepthMask(1);
        }

        /* Draw the GL "scene" */
        draw_gl();

        /* Finish the frame */
        glKosSwapBuffers();
    }

    return 0;
}