/* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above notice and this permission notice shall be included in all copies
* or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/* File for "Textures" lesson of the OpenGL tutorial on
* www.videotutorialsrock.com
*/
#include <iostream>
#include <stdlib.h>
#include <ios>
#include <assert.h>
#include <fstream>
#ifdef __APPLE__
#include <OpenGL/OpenGL.h>
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
#include "imageloader.h"
using namespace std;
void handleKeypress(unsigned char key, int x, int y) {
switch (key) {
case 27: //Escape key
exit(0);
}
}
//Makes the image into a texture, and returns the id of the texture
GLuint loadTexture(Image* image) {
GLuint textureId;
glGenTextures(1, &textureId); //Make room for our texture
glBindTexture(GL_TEXTURE_2D, textureId); //Tell OpenGL which texture to edit
//Map the image to the texture
glTexImage2D(GL_TEXTURE_2D, //Always GL_TEXTURE_2D
0, //0 for now
GL_RGB, //Format OpenGL uses for image
image->width, image->height, //Width and height
0, //The border of the image
GL_RGB, //GL_RGB, because pixels are stored in RGB format
GL_UNSIGNED_BYTE, //GL_UNSIGNED_BYTE, because pixels are stored
//as unsigned numbers
image->pixels); //The actual pixel data
return textureId; //Returns the id of the texture
}
GLuint _textureId; //The id of the texture
void initRendering() {
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_NORMALIZE);
glEnable(GL_COLOR_MATERIAL);
Image* image = loadBMP("vtr.bmp");
_textureId = loadTexture(image);
delete image;
}
void handleResize(int w, int h) {
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (float)w / (float)h, 1.0, 200.0);
}
void drawScene() {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0f, 1.0f, -6.0f);
GLfloat ambientLight[] = {0.2f, 0.2f, 0.2f, 1.0f};
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientLight);
GLfloat directedLight[] = {0.7f, 0.7f, 0.7f, 1.0f};
GLfloat directedLightPos[] = {-10.0f, 15.0f, 20.0f, 0.0f};
glLightfv(GL_LIGHT0, GL_DIFFUSE, directedLight);
glLightfv(GL_LIGHT0, GL_POSITION, directedLightPos);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, _textureId);
//Bottom
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glColor3f(1.0f, 0.2f, 0.2f);
glBegin(GL_QUADS);
glNormal3f(0.0, 1.0f, 0.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-2.5f, -2.5f, 2.5f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(2.5f, -2.5f, 2.5f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(2.5f, -2.5f, -2.5f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-2.5f, -2.5f, -2.5f);
glEnd();
//Back
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glColor3f(1.0f, 1.0f, 1.0f);
glBegin(GL_TRIANGLES);
glNormal3f(0.0f, 0.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-2.5f, -2.5f, -2.5f);
glTexCoord2f(5.0f, 5.0f);
glVertex3f(0.0f, 2.5f, -2.5f);
glTexCoord2f(10.0f, 0.0f);
glVertex3f(2.5f, -2.5f, -2.5f);
glEnd();
//Left
glDisable(GL_TEXTURE_2D);
glColor3f(1.0f, 0.7f, 0.3f);
glBegin(GL_QUADS);
glNormal3f(1.0f, 0.0f, 0.0f);
glVertex3f(-2.5f, -2.5f, 2.5f);
glVertex3f(-2.5f, -2.5f, -2.5f);
glVertex3f(-2.5f, 2.5f, -2.5f);
glVertex3f(-2.5f, 2.5f, 2.5f);
glEnd();
glutSwapBuffers();
}
int main(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(400, 400);
glutCreateWindow("Textures - videotutorialsrock.com");
initRendering();
glutDisplayFunc(drawScene);
glutKeyboardFunc(handleKeypress);
glutReshapeFunc(handleResize);
glutMainLoop();
return 0;
}
/* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above notice and this permission notice shall be included in all copies
* or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/* File for "Textures" lesson of the OpenGL tutorial on
* www.videotutorialsrock.com
*/
#include <iostream>
#include <stdlib.h>
#include <ios>
#include <assert.h>
#include <fstream>
#ifdef __APPLE__
#include <OpenGL/OpenGL.h>
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
#include "imageloader.h"
using namespace std;
Image::Image(char* ps, int w, int h) : pixels(ps), width(w), height(h) {
}
Image::~Image() {
delete[] pixels;
}
namespace {
//Converts a four-character array to an integer, using little-endian form
int toInt(const char* bytes) {
return (int)(((unsigned char)bytes[3] << 24) |
((unsigned char)bytes[2] << 16) |
((unsigned char)bytes[1] << 8) |
(unsigned char)bytes[0]);
}
//Converts a two-character array to a short, using little-endian form
short toShort(const char* bytes) {
return (short)(((unsigned char)bytes[1] << 8) |
(unsigned char)bytes[0]);
}
//Reads the next four bytes as an integer, using little-endian form
int readInt(ifstream &input) {
char buffer[4];
input.read(buffer, 4);
return toInt(buffer);
}
//Reads the next two bytes as a short, using little-endian form
short readShort(ifstream &input) {
char buffer[2];
input.read(buffer, 2);
return toShort(buffer);
}
//Just like auto_ptr, but for arrays
template<class T>
class auto_array {
private:
T* array;
mutable bool isReleased;
public:
explicit auto_array(T* array_ = NULL) :
array(array_), isReleased(false) {
}
auto_array(const auto_array<T> &aarray) {
array = aarray.array;
isReleased = aarray.isReleased;
aarray.isReleased = true;
}
~auto_array() {
if (!isReleased && array != NULL) {
delete[] array;
}
}
T* get() const {
return array;
}
T &operator*() const {
return *array;
}
void operator=(const auto_array<T> &aarray) {
if (!isReleased && array != NULL) {
delete[] array;
}
array = aarray.array;
isReleased = aarray.isReleased;
aarray.isReleased = true;
}
T* operator->() const {
return array;
}
T* release() {
isReleased = true;
return array;
}
void reset(T* array_ = NULL) {
if (!isReleased && array != NULL) {
delete[] array;
}
array = array_;
}
T* operator+(int i) {
return array + i;
}
T &operator[](int i) {
return array[i];
}
};
}
Image* loadBMP(const char* filename) {
ifstream input;
input.open(filename, ifstream::binary);
assert(!input.fail() || !"Could not find file");
char buffer[2];
input.read(buffer, 2);
assert((buffer[0] == 'B' && buffer[1] == 'M') || !"Not a bitmap file");
input.ignore(8);
int dataOffset = readInt(input);
//Read the header
int headerSize = readInt(input);
int width;
int height;
switch(headerSize) {
case 40:
//V3
width = readInt(input);
height = readInt(input);
input.ignore(2);
assert(readShort(input) == 24 || !"Image is not 24 bits per pixel");
assert(readShort(input) == 0 || !"Image is compressed");
break;
case 12:
//OS/2 V1
width = readShort(input);
height = readShort(input);
input.ignore(2);
assert(readShort(input) == 24 || !"Image is not 24 bits per pixel");
break;
case 64:
//OS/2 V2
assert(!"Can't load OS/2 V2 bitmaps");
break;
case 108:
//Windows V4
assert(!"Can't load Windows V4 bitmaps");
break;
case 124:
//Windows V5
assert(!"Can't load Windows V5 bitmaps");
break;
default:
assert(!"Unknown bitmap format");
}
//Read the data
int bytesPerRow = ((width * 3 + 3) / 4) * 4 - (width * 3 % 4);
int size = bytesPerRow * height;
auto_array<char> pixels(new char[size]);
input.seekg(dataOffset, ios_base::beg);
input.read(pixels.get(), size);
//Get the data into the right format
auto_array<char> pixels2(new char[width * height * 3]);
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
for(int c = 0; c < 3; c++) {
pixels2[3 * (width * y + x) + c] =
pixels[bytesPerRow * y + 3 * x + (2 - c)];
}
}
}
input.close();
return new Image(pixels2.release(), width, height);
}
/* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above notice and this permission notice shall be included in all copies
* or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/* File for "Textures" lesson of the OpenGL tutorial on
* www.videotutorialsrock.com
*/
#ifndef IMAGE_LOADER_H_INCLUDED
#define IMAGE_LOADER_H_INCLUDED
//Represents an image
class Image {
public:
Image(char* ps, int w, int h);
~Image();
/* An array of the form (R1, G1, B1, R2, G2, B2, ...) indicating the
* color of each pixel in image. Color components range from 0 to 255.
* The array starts the bottom-left pixel, then moves right to the end
* of the row, then moves up to the next column, and so on. This is the
* format in which OpenGL likes images.
*/
char* pixels;
int width;
int height;
};
//Reads a bitmap image from file.
Image* loadBMP(const char* filename);
#endif