#include <assert.h>
#include <fstream>
#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 {
//Konversi 4 buah karakter ke integer, menggunakan bentuk little-endian
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]);
}
//Konversi 2 buah karakter ke integer, menggunakan bentuk little-endian
short toShort(const char* bytes) {
return (short)(((unsigned char)bytes[1] << 8) |
(unsigned char)bytes[0]);
}
//Membaca 4 byte selanjutnya sebagai integer, menggunakan bentuk little-endian
int readInt(ifstream &input) {
char buffer[4];
input.read(buffer, 4);
return toInt(buffer);
}
short readShort(ifstream &input) {
char buffer[2];
input.read(buffer, 2);
return toShort(buffer);
}
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() || !"File tidak ditemukan!!!");
char buffer[2];
input.read(buffer, 2);
assert(buffer[0] == 'B' && buffer[1] == 'M' || !"Bukan file bitmap!!!");
input.ignore(8);
int dataOffset = readInt(input);
int headerSize = readInt(input);
int width;
int height;
switch(headerSize) {
case 40:
width = readInt(input);
height = readInt(input);
input.ignore(2);
assert(readShort(input) == 24 || !"Gambar tidak 24 bits per pixel!");
assert(readShort(input) == 0 || !"Gambar dikompres!");
break;
case 12:
width = readShort(input);
height = readShort(input);
input.ignore(2);
assert(readShort(input) == 24 || !"Gambar tidak 24 bits per pixel!");
break;
case 64:
assert(!"Tidak dapat mengambil OS/2 V2 bitmaps");
break;
case 108:
assert(!"Tidak dapat mengambil Windows V4 bitmaps");
break;
case 124:
assert(!"Tidak dapat mengambil Windows V5 bitmaps");
break;
default:
assert(!"Format bitmap ini tidak diketahui!");
}
//Membaca 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);
//Mengambil data yang mempunyai format benar
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);
}
2. Kemudian Kita buat juga file yang sudah ada di library nya openGL tersebut yaitu imageloader.h yang isinya sebagai berikut :
/* 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 "Putting It All Together" 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
3. Kita Buat fungsi main.cpp nya yang isinya sebagai berikut
#include <iostream>
#include <stdlib.h>
#ifdef __APPLE__
#include <OpenGL/OpenGL.h>
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
#include "imageloader.h"
using namespace std;
const float BOX_SIZE = 7.0f; //Panjang tiap sisi kubus
float _angle = 0; //Rotasi terhadap box
GLuint _textureId; //ID OpenGL untuk tekstur
void handleKeypress(unsigned char key, int x, int y) {
switch (key) {
case 27: //Tekan Escape untuk EXIT
exit(0);
}
}
//Membuat gambar menjadi tekstur kemudian berikan ID pada tekstur
GLuint loadTexture(Image* image) {
GLuint textureId;
glGenTextures(1, &textureId);
glBindTexture(GL_TEXTURE_2D, textureId);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, image->width, image->height, 0, GL_RGB, GL_UNSIGNED_BYTE, image->pixels);
return textureId;
}
void initRendering() {
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_NORMALIZE);
glEnable(GL_COLOR_MATERIAL);
Image* image = loadBMP("Yoona.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, 0.0f, -20.0f);
GLfloat ambientLight[] = {0.3f, 0.3f, 0.3f, 1.0f};
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientLight);
GLfloat lightColor[] = {0.7f, 0.7f, 0.7f, 1.0f};
GLfloat lightPos[] = {-2 * BOX_SIZE, BOX_SIZE, 4 * BOX_SIZE, 1.0f};
glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColor);
glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
glRotatef(-_angle, 1.0f, 1.0f, 0.0f);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, _textureId);
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_QUADS);
//glBegin(GL_QUADS);
//Sisi atas
glTexCoord2f(0.0f, 0.0f);
glNormal3f(0.0, 1.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
//Sisi bawah
glTexCoord2f(0.0f, 0.0f);
glNormal3f(0.0, -1.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
//Sisi kiri
glNormal3f(-1.0, 0.0f, 0.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
//Sisi kanan
glNormal3f(1.0, 0.0f, 0.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
//glEnd();
//Sisi depan
glNormal3f(0.0, 0.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, BOX_SIZE / 2);
//Sisi belakang
glNormal3f(0.0, 0.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(-BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, BOX_SIZE / 2, -BOX_SIZE / 2);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(BOX_SIZE / 2, -BOX_SIZE / 2, -BOX_SIZE / 2);
glEnd();
glDisable(GL_TEXTURE_2D);
glutSwapBuffers();
}
//Panggil setiap 25ms
void update(int value) {
_angle += 1.0f;
if (_angle > 360) {
_angle -= 360;
}
glutPostRedisplay();
glutTimerFunc(25, update, 0);
}
int main(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(400, 400);
glutCreateWindow("evangs-ganteng");
initRendering();
glutDisplayFunc(drawScene);
glutKeyboardFunc(handleKeypress);
glutReshapeFunc(handleResize);
glutTimerFunc(25, update, 0);
glutMainLoop();
return 0;
}
4. Gunakan Image yang berextensi .bmp selain itu image tidak akan terbaca oleh openGL nya maka dari itu kita harus memakai .bmp
5. Setelah semua file terbuat simpan dalam folder yang sama di dalam folder dev c++ nya kalo memakai dev
6. Apabila ingin mengganti gambar yang ada di sisi kubus nya tinggal ubah pada coding berikut yg berada dalam fungsi main nya :
Image* image = loadBMP("Yoona.bmp");
Ubah yang berada dalam tanda "" dengan nama file gambar yang ingin di sisip kan
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