texturedquad.cpp

This code was developed by my techer. :D

#include "objects/texturedQuad.h"
#include "SDL.h"
#include "SDL_opengl.h"
#include <iostream>
using namespace std;

TexturedQuad::TexturedQuad(float x, float y, float z, float rotx, float roty, float rotz):
Rendereable(x,y,z,rotx,roty,rotz)
{

	SDL_Surface*	surface;
	GLenum texture_format;
	GLint  nOfColors;
	string bitmapName = "resources/sample.bmp";

	surface = SDL_LoadBMP(bitmapName.c_str());
	if (surface == NULL) {
		cerr << "No se puede cargar el bitmap: "<< bitmapName.c_str() << endl;
		exit( 0 );
	}

	// Verificar si el ancho es una potencia de dos
	if ( (surface->w & (surface->w - 1)) != 0 ) {
		cerr << "Atencion: " << bitmapName.c_str() << " no posee ancho en potencias de dos" << endl;
	}

	// Tambien verificar si el alto es una potencia de dos
	if ( (surface->h & (surface->h - 1)) != 0 ) {
		cerr << "Atencion: " << bitmapName.c_str() << " no posee alto en potencias de dos" << endl;
	}

	//n鷐ero bytes colores por pixel
	nOfColors = surface->format->BytesPerPixel;
	if (nOfColors == 4)     // tiene alfa
	{
		if (surface->format->Rmask == 0x000000ff)
			texture_format = GL_RGBA;
		else
			texture_format = GL_BGRA;
	}
	else if (nOfColors == 3)     // no tiene alfa
	{
		if (surface->format->Rmask == 0x000000ff)
			texture_format = GL_RGB;
		else
			texture_format = GL_BGR;
	}
	else
	{
		cerr << "Atencion: la imagen no esta en truecolor. El archivo puede estar da馻do" << endl;

		// hay que prestar atenci髇 a este error y tomar una descic髇 acorde
		texture_format = GL_RGB;
	}


	//habilito las texturas
	glEnable(GL_TEXTURE_2D);

	//genero un nuevo identificador de texturas
	glGenTextures( 1, &this->textureId );

	//indico que textura es la seleccionada
	glBindTexture( GL_TEXTURE_2D, this->textureId );

	// Set the texture's stretching properties
	glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	//cargo la textura
	glTexImage2D( GL_TEXTURE_2D, 0, nOfColors, surface->w, surface->h, 0,
		texture_format, GL_UNSIGNED_BYTE, surface->pixels );

	//deshabilito las texturas
	glDisable(GL_TEXTURE_2D);

	if ( surface ) { 
		SDL_FreeSurface( surface );
	}
}

TexturedQuad::~TexturedQuad()
{}

void TexturedQuad::draw()
{
	glPushMatrix();
	glTranslatef( this->x, this->y, this->z );

	if( this->rotx != 0 )
	{
		glRotatef( this->rotx, 1.f,0.f,0.f );
	}
	if( this->roty != 0 )
	{
		glRotatef( this->roty, 0.f,1.f,0.f );
	}
	if( this->rotz != 0 )
	{
		glRotatef( this->rotz, 0.f,0.f,1.f );
	}

	glColor3f( 1.f,1.f,1.f );
	glEnable( GL_TEXTURE_2D );
	glBindTexture( GL_TEXTURE_2D, this->textureId );
	glBegin( GL_QUADS );
		//Top-left vertex (corner)
		glTexCoord2i( 1, 0 );
		glVertex3f( -1.4f, 1.f, 0.f );
		
		//Bottom-left vertex (corner)
		glTexCoord2i( 1, 1 );
		glVertex3f( -1.4f, -1.f, 0.f );
		
		//Bottom-right vertex (corner)
		glTexCoord2i( 0, 1 );
		glVertex3f( 1.4f, -1.f, 0.f );
		
		//Top-right vertex (corner)
		glTexCoord2i( 0, 0 );
		glVertex3f( 1.4f, 1.f, 0.f );
	glEnd();
	glDisable( GL_TEXTURE_2D );
	glPopMatrix();
}