// RenderArea2D.cxx - a class to manage 2D polygon-based drawing
//                    for a complex instrument (eg. GPS).
//
// Written by David Luff, started 2005.
//
// Copyright (C) 2005 - David C Luff - david.luff@nottingham.ac.uk
//
// 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// $Id$

#include "render_area_2d.hxx"
//#include <iostream>

#include <plib/ssg.h>

//using namespace std;



static const float dummy_normals[][3] = {{0.0f, 0.0f, 0.0f},
                                         {0.0f, 0.0f, 0.0f},
                                         {0.0f, 0.0f, 0.0f},
                                         {0.0f, 0.0f, 0.0f}};

RA2DPrimitive::RA2DPrimitive() {
	invert = false;
	debug = false;
}
										 
RenderArea2D::RenderArea2D(int logx, int logy, int sizex, int sizey, int posx, int posy) {
	_logx = logx;
	_logy = logy;
	_sizex = sizex;
	_sizey = sizey;
	_posx = posx;
	_posy = posy;
	_clipx1 = 0;
	_clipx2 = _logx - 1;
	_clipy1 = 0;
	_clipy2 = _logy - 1;
	
	_backgroundColor[0] = 0.0;
	_backgroundColor[1] = 0.0;
	_backgroundColor[2] = 0.0;
	_backgroundColor[3] = 1.0;
	_pixelColor[0] = 1.0;
	_pixelColor[1] = 0.0;
	_pixelColor[2] = 0.0;
	_pixelColor[3] = 1.0;
	
	_ra2d_debug = false;
}

void RenderArea2D::draw() {
    glDisable(GL_TEXTURE_2D);
	/*
    glColor3f(1, 1, 0);
	
	float x1 = _posx;
	float x2 = _posx + _sizex;
	float y1 = _posy;
	float y2 = _posy + _sizey;
	
	glBegin(GL_LINE_LOOP);
    glVertex2f(x1, y1);
    glVertex2f(x1, y2);
    glVertex2f(x2, y2);
    glVertex2f(x2, y1);
    glEnd();
	*/
	oldDrawBackground();
	
	for(unsigned int i = 0; i < drawing_list.size(); ++i) {
		RA2DPrimitive prim = drawing_list[i];
		switch(prim.type) {
		case RA2D_LINE:
			oldDrawLine(prim.x1, prim.y1, prim.x2, prim.y2);
			break;
		case RA2D_QUAD:
			if(prim.debug) {
				//cout << "Clipping = " << _clipx1 << ", " << _clipy1 << " to " << _clipx2 << ", " << _clipy2 << '\n';
				//cout << "Drawing quad " << prim.x1 << ", " << prim.y1 << " to " << prim.x2 << ", " << prim.y2 << '\n';
			}
			oldDrawQuad(prim.x1, prim.y1, prim.x2, prim.y2, prim.invert);
			break;
		case RA2D_PIXEL:
			oldDrawPixel(prim.x1, prim.y1, prim.invert);
			break;
		}
	}
	
	glEnable(GL_TEXTURE_2D);
}

// Set clipping region in logical units
void RenderArea2D::SetClipRegion(int x1, int y1, int x2, int y2) {
	_clipx1 = x1;
	_clipx2 = x2;
	_clipy1 = y1;
	_clipy2 = y2;
	//cout << "Set clip region, clip region = "  << _clipx1 << ", " << _clipy1 << " to " << _clipx2 << ", " << _clipy2 << '\n';
}

// Set clip region to be the same as the rendered area (default)
void RenderArea2D::ResetClipRegion() {
	_clipx1 = 0;
	_clipx2 = _logx - 1;
	_clipy1 = 0;
	_clipy2 = _logy - 1;
	//cout << "Reset clip region, clip region = "  << _clipx1 << ", " << _clipy1 << " to " << _clipx2 << ", " << _clipy2 << '\n';
}

void RenderArea2D::SetPosition(int posx, int posy) {
	_posx = posx;
	_posy = posy;
}

void RenderArea2D::SetLogicalSize(int logx, int logy) {
	_logx = logx;
	_logy = logy;
}

void RenderArea2D::SetActualSize(int sizex, int sizey) {
	_sizex = sizex;
	_sizey = sizey;
}

void RenderArea2D::DrawPixel(int x, int y, bool invert) {
	// Clipping is currently performed in oldDrawPixel - could clip here instead though.

	RA2DPrimitive prim;
	prim.x1 = x;
	prim.y1 = y;
	prim.x2 = 0;
	prim.y2 = 0;
	prim.type = RA2D_PIXEL;
	prim.invert = invert;
	drawing_list.push_back(prim);
}

void RenderArea2D::oldDrawPixel(int x, int y, bool invert) {
	// Clip
	if(x < _clipx1 || x > _clipx2 || y < _clipy1 || y > _clipy2) return;
	
	// Scale to position within background
	float fx1 = (float)x, fy1 = (float)y;
	float rx = (float)_sizex / (float)_logx;
	float ry = (float)_sizey / (float)_logy;
	fx1 *= rx;
	fy1 *= ry;
	float fx2 = fx1 + rx;
	float fy2 = fy1 + ry;
	
	// Translate to final position
	fx1 += (float)_posx;
	fx2 += (float)_posx;
	fy1 += (float)_posy;
	fy2 += (float)_posy;
	
	//cout << "DP: " << fx1 << ", " << fy1 << " ... " << fx2 << ", " << fy2 << '\n';
	
	doSetColor(invert ? _backgroundColor : _pixelColor);
	sgVec2 corners[4];
	sgSetVec2(corners[0], fx1, fy1);
	sgSetVec2(corners[1], fx2, fy1);
	sgSetVec2(corners[2], fx2, fy2);
	sgSetVec2(corners[3], fx1, fy2);
	//cout << "Drawing pixel, x,y is " << x << ", " << y << ", fx is [x1,x2,y1,y2] " << fx1 << ", " << fx2 << ", " << fy1 << ", " << fy2 << '\n';
	doDrawQuad(&corners[0], dummy_normals);
}

void RenderArea2D::DrawLine(int x1, int y1, int x2, int y2) {
	RA2DPrimitive prim;
	prim.x1 = x1;
	prim.y1 = y1;
	prim.x2 = x2;
	prim.y2 = y2;
	prim.type = RA2D_LINE;
	prim.invert = false;
	drawing_list.push_back(prim);
}

void RenderArea2D::oldDrawLine(int x1, int y1, int x2, int y2) {
	// Crude implementation of Bresenham line drawing algorithm.
	
	// Our lines are non directional, so first order the points x-direction-wise to leave only 4 octants to consider.
	if(x2 < x1) {
		int tmp_x = x1;
		int tmp_y = y1;
		x1 = x2;
		y1 = y2;
		x2 = tmp_x;
		y2 = tmp_y;
	}
	
	bool flip_y = (y1 > y2 ? true : false);
	int dx = x2 - x1;
	int dy = (flip_y ? y1 - y2 : y2 - y1); 
	if(dx > dy) {
		// push the x dir
		int y = y1;
		int yn = dx/2;
		for(int x=x1; x<=x2; ++x) {
			DrawPixel(x, y);
			yn += dy;
			if(yn >= dx) {
				yn -= dx;
				y = (flip_y ? y - 1 : y + 1);
			}
		}
	} else {
		// push the y dir
		int x = x1;
		int xn = dy/2;
		// Must be a more elegant way to roll the next two cases into one!
		if(flip_y) {
			for(int y=y1; y>=y2; --y) {
				DrawPixel(x, y);
				xn += dx;
				if(xn >= dy) {
					xn -= dy;
					x++;
				}
			}
		} else {
			for(int y=y1; y<=y2; ++y) {
				DrawPixel(x, y);
				xn += dx;
				if(xn >= dy) {
					xn -= dy;
					x++;
				}
			}
		}
	}
}

void RenderArea2D::DrawQuad(int x1, int y1, int x2, int y2, bool invert) {
	// Clip and sanity-check.
	if(x1 > x2) {
		int x = x2;
		x2 = x1;
		x1 = x;
	}
	if(y1 > y2) {
		int y = y2;
		y2 = y1;
		y1 = y;
	}
	x1 = x1 < _clipx1 ? _clipx1 : x1;
	if(x1 > _clipx2) { return; }
	x2 = x2 > _clipx2 ? _clipx2 : x2;
	if(x2 < _clipx1) { return; }
	y1 = y1 < _clipy1 ? _clipy1 : y1;
	if(y1 > _clipy2) { return; }
	y2 = y2 > _clipy2 ? _clipy2 : y2;
	if(y2 < _clipy1) { return; }
	
	RA2DPrimitive prim;
	prim.x1 = x1;
	prim.y1 = y1;
	prim.x2 = x2;
	prim.y2 = y2;
	prim.type = RA2D_QUAD;
	prim.invert = invert;
	if(_ra2d_debug) prim.debug = true;
	drawing_list.push_back(prim);
}

void RenderArea2D::oldDrawQuad(int x1, int y1, int x2, int y2, bool invert) {
	// Scale to position within background
	float fx1 = (float)x1, fy1 = (float)y1;
	float fx2 = (float)x2, fy2 = (float)y2;
	float rx = (float)_sizex / (float)_logx;
	float ry = (float)_sizey / (float)_logy;
	fx1 *= rx;
	fy1 *= ry;
	fx2 *= rx;
	fy2 *= ry;
	
	fx2 += rx;
	fy2 += ry;
	
	// Translate to final position
	fx1 += (float)_posx;
	fx2 += (float)_posx;
	fy1 += (float)_posy;
	fy2 += (float)_posy;
	
	//cout << "DP: " << fx1 << ", " << fy1 << " ... " << fx2 << ", " << fy2 << '\n';
	
	doSetColor(invert ? _backgroundColor : _pixelColor);
	sgVec2 corners[4];
	sgSetVec2(corners[0], fx1, fy1);
	sgSetVec2(corners[1], fx2, fy1);
	sgSetVec2(corners[2], fx2, fy2);
	sgSetVec2(corners[3], fx1, fy2);
	doDrawQuad(&corners[0], dummy_normals);
}

void RenderArea2D::DrawBackground() {
	// TODO
}

void RenderArea2D::oldDrawBackground() {
	doSetColor(_backgroundColor);
	sgVec2 corners[4];
	sgSetVec2(corners[0], (float)_posx, (float)_posy);
	sgSetVec2(corners[1], (float)(_posx + _sizex), (float)_posy);
	sgSetVec2(corners[2], (float)(_posx + _sizex), (float)(_posy + _sizey));
	sgSetVec2(corners[3], (float)_posx, (float)(_posy + _sizey));
	doDrawQuad(&corners[0], dummy_normals);
}

void RenderArea2D::Flush() {
	drawing_list.clear();
}

// -----------------------------------------
//
// Actual drawing routines copied from Atlas
//
// -----------------------------------------

void RenderArea2D::doSetColor( const float *rgba ) {
  glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, rgba);
  glColor4fv( rgba );
}

void RenderArea2D::doDrawQuad( const sgVec2 *p, const sgVec3 *normals ) {
	//cout << "doDrawQuad: " << *p[0] << ", " << *(p[0]+1) << ", " << *p[1] << ", " << *(p[1]+1) << ", " << *p[2] << ", " << *p([2]+1) << ", " << *p[3] << ", " << *p([3]+1) <<'\n';
  glBegin(GL_QUADS);
  glNormal3fv( normals[0] ); glVertex2fv( p[0] );
  glNormal3fv( normals[1] ); glVertex2fv( p[1] );
  glNormal3fv( normals[2] ); glVertex2fv( p[2] );
  glNormal3fv( normals[3] ); glVertex2fv( p[3] );
  glEnd();
}

void RenderArea2D::doDrawQuad( const sgVec2 *p, const sgVec3 *normals, const sgVec4 *color ) {
  glBegin(GL_QUADS);
    glColor4fv( color[0] );glNormal3fv( normals[0] ); glVertex2fv( p[0] );
    glColor4fv( color[1] );glNormal3fv( normals[1] ); glVertex2fv( p[1] );
    glColor4fv( color[2] );glNormal3fv( normals[2] ); glVertex2fv( p[2] );
    glColor4fv( color[3] );glNormal3fv( normals[3] ); glVertex2fv( p[3] );
  glEnd();
}