/*
 *  mogltk
 *  Copyright (C) 1999-2004 Nicolas "Pixel" Noble
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/* $Id: glbase.cc,v 1.21 2004-10-19 01:27:30 pixel Exp $ */

#include <stdio.h>
#include <SDL.h>
#include <SDL_opengl.h>
#include <Output.h>
#include <Handle.h>
#include "glbase.h"
#include "engine.h"
#include "generic.h"
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

mogltk::glbase::glbase(int w, int h, int flags) throw (GeneralException) : mogltk::base(w, h, flags, 0), twoD(0), fovy(60.0) {
    SDL_Surface * surface;
    GLint bits;

    mogltk::engine::setup();
    if (SDL_InitSubSystem(SDL_INIT_VIDEO) < 0) {
        throw GeneralException(String("Couldn't initialise Video SubSystem: ") + SDL_GetError());
    }

#if 1
    SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
//    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 32);
    SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_ACCUM_RED_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_ACCUM_GREEN_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_ACCUM_BLUE_SIZE, 8);
#endif  
    if (!(surface = SDL_SetVideoMode(w, h, 0, flags | SDL_OPENGL | SDL_HWSURFACE))) {
        throw GeneralException(String("Couldn't set GL mode: ") + SDL_GetError());
    }
    
    mogltk::engine::glbase_o = this;
    mogltk::engine::base_o = this;

    ratio = (GLdouble) surface->w / surface->h;

    glGetIntegerv(GL_STENCIL_BITS, &bits);

    printm(M_INFO, "Video resolution: %dx%dx%d (ratio = %3.2f)\n", surface->w, surface->h, surface->format->BitsPerPixel, ratio);
    printm(M_INFO, "\n");
    printm(M_INFO, "OpenGL infos\n");
    printm(M_INFO, "------------\n");
    printm(M_INFO, String("Vendor    : ") + (char *) glGetString(GL_VENDOR) + "\n");
    printm(M_INFO, String("Renderer  : ") + (char *) glGetString(GL_RENDERER) + "\n");
    printm(M_INFO, String("Version   : ") + (char *) glGetString(GL_VERSION) + "\n");
    printm(M_INFO, String("Extensions: ") + (char *) glGetString(GL_EXTENSIONS) + "\n");

    glViewport(0, 0, surface->w, surface->h);

    glCullFace(GL_BACK);
    glFrontFace(GL_CCW);
    glEnable(GL_CULL_FACE);

    glClearColor(0, 0, 0, 0);
    glShadeModel(GL_SMOOTH);
    
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(fovy, ratio, 1.0, 1024.0);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
    SDL_GL_SwapBuffers();
    SDL_ShowCursor(SDL_DISABLE);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
    setsurface(surface);
    mogltk::engine::postsetup();
}

mogltk::glbase::~glbase() {
}

void mogltk::glbase::Enter2DMode(void) {
    if (twoD)
	return;
    
    glPushAttrib(GL_ENABLE_BIT);
    glDisable(GL_DEPTH_TEST);
    glDisable(GL_CULL_FACE);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadIdentity();
    glOrtho(0.0, GetWidth(), GetHeight(), 0.0, 0.0, 1.0);
    
    glMatrixMode(GL_MODELVIEW);
    glPushMatrix();
    glLoadIdentity();
    
    twoD = 1;
}

void mogltk::glbase::Leave2DMode(void) {
    if (!twoD)
	return;
    
    glMatrixMode(GL_MODELVIEW);
    glPopMatrix();
    glMatrixMode(GL_PROJECTION);
    glPopMatrix();
    
    glPopAttrib();
    
    twoD = 0;
}

void mogltk::glbase::Flip(bool clear) {
    mogltk::engine::pollevents();
    SDL_GL_SwapBuffers();
    if (clear)
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}

bool mogltk::glbase::is2D() {
    return twoD;
}

void mogltk::glbase::glVertex(GLshort x, GLshort y, GLshort z, GLshort w) {
#ifdef DEBUG
    printm(M_INFO, "Calling glVertex(%i, %i, %i, %i) (shorts)\n", x, y, z, w);
#endif
    glVertex4i(x, y, z, w);
}

void mogltk::glbase::glVertex(GLint x, GLint y, GLint z, GLint w) {
#ifdef DEBUG
    printm(M_INFO, "Calling glVertex(%i, %i, %i, %i) (ints)\n", x, y, z, w);
#endif
    glVertex4i(x, y, z, w);
}

void mogltk::glbase::glVertex(GLfloat x, GLfloat y, GLfloat z, GLfloat w) {
#ifdef DEBUG
    printm(M_INFO, "Calling glVertex(%f, %f, %f, %f) (floats)\n", x, y, z, w);
#endif
    glVertex4f(x, y, z, w);
}

void mogltk::glbase::glVertex(GLdouble x, GLdouble y, GLdouble z, GLdouble w) {
#ifdef DEBUG
    printm(M_INFO, "Calling glVertex(%f, %f, %f, %f) (doubles)\n", x, y, z, w);
#endif
    glVertex4d(x, y, z, w);
}

void mogltk::glbase::changeviewport(int x, int y, unsigned int w, unsigned int h) {
#if 0
    if ((w == 0) && (h == 0)) {
	w = GetWidth() - x;
	h = GetHeight() - y;
    }

    ratio = (GLdouble) w / h;
    glViewport(x, y, w, h);
    if (!engine::base_o->is2D())
	gluPerspective(fovy, ratio, 1.0, 1024.0);
#endif
    glScissor(x, GetHeight() - y - h - 1, w + 1, h + 1);
    glEnable(GL_SCISSOR_TEST);
}

void mogltk::glbase::changefovy(GLdouble nfoyv) {
    fovy = nfoyv;
    if (!engine::base_o->is2D())
	gluPerspective(fovy, ratio, 1.0, 1024.0);
}

inline static unsigned int nextpower(unsigned int n) {
    unsigned int i;

    if (!n)
        return n;

    if (ISPOT(n))
        return n;

    for (i = 31; i >= 0; i--) {
        if ((n >> i) & 1) {
            return 1 << (i + 1);
        }
    }
}

mogltk::texture * mogltk::glbase::GrabTexture() {
    int w = nextpower(GetWidth());
    int h = nextpower(GetHeight());
    texture * r = new texture(w, h);
    SDL_Surface * t;

    t = GrabSurface();
    SDL_BlitSurface(t, NULL, r->GetSurface(), NULL);
    SDL_FreeSurface(t);

    return r;
}

SDL_Surface * mogltk::glbase::GrabSurface() {
    int i;
    SDL_Surface * r;
    Uint8 * pixels = (Uint8 *) malloc(GetWidth() * GetHeight() * 3);
    Uint8 * s, * d;

    glReadPixels(0, 0, GetWidth(), GetHeight(), GL_RGB, GL_UNSIGNED_BYTE, pixels);

    r = SDL_CreateRGBSurface(SDL_SWSURFACE, GetWidth(), GetHeight(), 24,
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
	0xff000000,
	0x00ff0000,
	0x0000ff00,
	0x00000000
#else
	0x000000ff,
	0x0000ff00,
	0x00ff0000,
	0x00000000
#endif
        );

    for (i = 0; i < GetHeight(); i++) {
        s = pixels + i * GetWidth() * 3;
        d = ((Uint8 *) r->pixels) + (GetHeight() - i - 1) * GetWidth() * 3;
        memcpy(d, s, GetWidth() * 3);
    }

    free(pixels);

    return r;
}