Im trying to load a texture from a bmp (loaded to imgur as bmp https://imgur.com/a/ZGscbqc you can see it when downloaded imgur doesn't render bmp) and then display it on the front side of a object. When I try it with a solidcube the whole cube just goes a weird color and when the camera gets close to the cube my fps gets really low
I dont want to use additional libraries and here is the function to load the texture
GLuint LoadTexture( const char * filename )
{
GLuint texture;
int width, height;
unsigned char * data;
FILE * file;
file = fopen( filename, "rb" );
if ( file == NULL ) return 0;
width = 238; //Exact dimension of my picture
height = 419;
data = (unsigned char *)malloc( width * height * 3 );
//int size = fseek(file,);
fread( data, width * height * 3, 1, file );
fclose( file );
for(int i = 0; i < width * height ; ++i)
{
int index = i*3;
unsigned char B,R;
B = data[index];
R = data[index+2];
data[index] = R;
data[index+2] = B;
}
glGenTextures( 1, &texture );
glBindTexture( GL_TEXTURE_2D, texture );
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,GL_REPEAT );
gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width, height,GL_RGB, GL_UNSIGNED_BYTE, data );
free( data );
return texture;
}
and then I call it in my renderScene function
GLuint texture;
texture= LoadTexture( "Princess_Peach_Stock_Art.bmp" );
glEnable( GL_TEXTURE_2D );
glBindTexture (GL_TEXTURE_2D, texture);
//princess
glPushMatrix();
glTranslatef(-10,19,-95);
glColor3f(1.0f,1.0f,1.0f);
glutSolidCube(10);
glPopMatrix();
glDisable( GL_TEXTURE_2D );
2 Questions
Here is a minimal repoducable code (I left the moving and the camera orientation code so that it will be easier to see and get close to it)
#include <math.h>
#include <GL/glut.h>
#include <stdio.h>
#include <string.h>
#include <cstdint>
#include <iostream>
#define HEIGHT 20
#define WIDTH 20
GLUquadricObj *objCylinder = gluNewQuadric();
float angle=0.0,deltaAngle = 0.0,ratio;
float x=0.0f,y=1.75f,z=75.0f;
float lx=0.0f,ly=0.0f,lz=-1.0f;
int deltaMove = 0,h,w;
static GLubyte pattern[WIDTH][HEIGHT][4]; //height, width, RGBA
unsigned char *pattern2;
static GLuint texName[10];
unsigned long width, height;
GLfloat no_mat[] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat mat_diffuse[] = { 0.1, 0.5, 0.8, 1.0 };
GLfloat no_shininess[] = { 0.0 };
GLfloat high_shininess[] = { 100.0 };
GLuint LoadTexture( const char * filename )
{
GLuint texture;
int width, height;
unsigned char * data;
FILE * file;
file = fopen( filename, "rb" );
if ( file == NULL ) return 0;
width = 238; //Exact dimension of my picture
height = 419;
data = (unsigned char *)malloc( width * height * 3 );
//int size = fseek(file,);
fread( data, width * height * 3, 1, file );
fclose( file );
for(int i = 0; i < width * height ; ++i)
{
int index = i*3;
unsigned char B,R;
B = data[index];
R = data[index+2];
data[index] = R;
data[index+2] = B;
}
glGenTextures( 1, &texture );
glBindTexture( GL_TEXTURE_2D, texture );
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,GL_REPEAT );
gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width, height,GL_RGB, GL_UNSIGNED_BYTE, data );
free( data );
return texture;
}
void changeSize(int w1, int h1){
if(h1 == 0)
h1 = 1;
w = w1;
h = h1;
ratio = 1.0f * w / h;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glViewport(0, 0, w, h);
gluPerspective(45,ratio,0.1,1000);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(x, y, z, x + lx,y + ly,z + lz, 0.0f,1.0f,0.0f);
}
void setLight(void)
{
GLfloat L0position[]={30.0, 10.0, 40.0, 1.0};
GLfloat L1position[]={0.0, 0.0, -100.0, 1.0};
GLfloat whitelight[]={1.0, 1.0, 1.0, 1.0};
GLfloat amblight[]={0.2, 0.2, 0.2, 1.0};
GLfloat blacklight[]={0.0, 0.0, 0.0, 1.0};
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amblight);
GLfloat whitelight1[]={0, 0, 0, 1.0};
glLightfv(GL_LIGHT0, GL_AMBIENT, blacklight);
glLightfv(GL_LIGHT0, GL_SPECULAR, whitelight);
glLightfv(GL_LIGHT0, GL_DIFFUSE, whitelight);
glLightfv(GL_LIGHT0, GL_POSITION, L0position);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
}
void orientMe(float ang) {
lx = sin(ang);
lz = -cos(ang);
glLoadIdentity();
gluLookAt(x, y, z,
x + lx,y + ly,z + lz,
0.0f,1.0f,0.0f);
}
void moveMeFlat(int i) {
x = x + i*(lx)*0.08;
z = z + i*(lz)*0.08;
glLoadIdentity();
gluLookAt(x, y, z,
x + lx,y + ly,z + lz,
0.0f,1.0f,0.0f);
}
void renderScene(void) {
if (deltaMove)
moveMeFlat(deltaMove);
if (deltaAngle) {
angle += deltaAngle;
orientMe(angle);
}
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
setLight();
glEnable(GL_COLOR_MATERIAL);
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
glColor3f(0.9f, 0.9f, 0.9f);
glBegin(GL_QUADS);
glMaterialfv(GL_FRONT, GL_AMBIENT, no_mat);
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, no_mat);
glMaterialfv(GL_FRONT, GL_SHININESS, no_shininess);
glMaterialfv(GL_FRONT, GL_EMISSION, no_mat);
glVertex3f(-500.0f, 0.0f, -500.0f);
glVertex3f(-500.0f, 0.0f, 500.0f);
glVertex3f( 500.0f, 0.0f, 500.0f);
glVertex3f( 500.0f, 0.0f, -500.0f);
glEnd();
GLuint texture;
texture= LoadTexture( "Princess_Peach_Stock_Art.bmp" );
glEnable( GL_TEXTURE_2D );
glBindTexture (GL_TEXTURE_2D, texture);
//princess
glPushMatrix();
glTranslatef(-10,19,-95);
glColor3f(1.0f,1.0f,1.0f);
glutSolidCube(10);
glPopMatrix();
glDisable( GL_TEXTURE_2D );
glDisable(GL_COLOR_MATERIAL);
glutSwapBuffers();
}
void pressKey(int key, int x, int y) {
switch (key) {
case GLUT_KEY_LEFT : deltaAngle = -0.001f;break;
case GLUT_KEY_RIGHT : deltaAngle = 0.001f;break;
case GLUT_KEY_UP : deltaMove = 1;break;
case GLUT_KEY_DOWN : deltaMove = -1;break;
}
}
void releaseKey(int key, int x, int y) {
switch (key) {
case GLUT_KEY_LEFT : if (deltaAngle < 0.0f)
deltaAngle = 0.0f;
break;
case GLUT_KEY_RIGHT : if (deltaAngle > 0.0f)
deltaAngle = 0.0f;
break;
case GLUT_KEY_UP : if (deltaMove > 0)
deltaMove = 0;
break;
case GLUT_KEY_DOWN : if (deltaMove < 0)
deltaMove = 0;
break;
}
}
void initWindow() {
glutIgnoreKeyRepeat(1);
glutSpecialFunc(pressKey);
glutSpecialUpFunc(releaseKey);
glutDisplayFunc(renderScene);
glutIdleFunc(renderScene);
glutReshapeFunc(changeSize);
glShadeModel (GL_SMOOTH);
glEnable(GL_LIGHTING);
glEnable(GL_DEPTH_TEST);
glEnable(GL_NORMALIZE);
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowPosition(100,100);
glutInitWindowSize(640,360);
glutCreateWindow("2");
initWindow();
glutMainLoop();
return(0);
}
Edit:
glutSolidCube doesn't apply texture coordinates: How to apply texture to glutSolidCube
fseek( file, 14+108, SEEK_CUR ); as per https://www.fileformat.info/format/bmp/egff.htm#MICBMP-DMYID.3
glTexImage2D accepts GL_BGR: https://registry.khronos.org/OpenGL-Refpages/gl4/html/glTexImage2D.xhtml
Learning mordern C++ can be time-consuming, so it can't be a priority in this case.
Original answer:
There is really no reason not to use something like the following single-header library: https://github.com/nothings/stb/blob/master/stb_image.h
I managed to make a hint of progress in your code. It now shows a distorted princess in a quad.
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#include <math.h>
#include <GL/glut.h>
#include <stdio.h>
#include <string.h>
#include <cstdint>
#include <iostream>
#define HEIGHT 20
#define WIDTH 20
GLUquadricObj *objCylinder = gluNewQuadric();
float angle=0.0,deltaAngle = 0.0,ratio;
float x=0.0f,y=1.75f,z=75.0f;
float lx=0.0f,ly=0.0f,lz=-1.0f;
int deltaMove = 0,h,w;
GLuint princessTexture;
static GLubyte pattern[WIDTH][HEIGHT][4]; //height, width, RGBA
unsigned char *pattern2;
static GLuint texName[10];
unsigned long width, height;
GLfloat no_mat[] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat mat_diffuse[] = { 0.1, 0.5, 0.8, 1.0 };
GLfloat no_shininess[] = { 0.0 };
GLfloat high_shininess[] = { 100.0 };
GLuint LoadTexture( const char * filename )
{
GLuint texture;
int width, height, nrChannels;
unsigned char *data = stbi_load(filename, &width, &height, &nrChannels, 0);
if (!data) {
std::cout << "Couldn't load texture " << filename << " :(" << std::endl;
return 0;
}
std::cout << width << " × " << height << ", " << nrChannels << "ch" << std::endl;
glGenTextures( 1, &texture );
glBindTexture( GL_TEXTURE_2D, texture );
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE );
//gluBuild2DMipmaps takes care of minification
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR );
//glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,GL_REPEAT );
//glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,GL_REPEAT );
gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width, height,GL_RGB, GL_UNSIGNED_BYTE, data );
//glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
stbi_image_free(data);
return texture;
}
void changeSize(int w1, int h1){
if(h1 == 0)
h1 = 1;
w = w1;
h = h1;
ratio = 1.0f * w / h;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glViewport(0, 0, w, h);
gluPerspective(45,ratio,0.1,1000);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(x, y, z, x + lx,y + ly,z + lz, 0.0f,1.0f,0.0f);
}
void setLight(void)
{
GLfloat L0position[]={30.0, 10.0, 40.0, 1.0};
GLfloat L1position[]={0.0, 0.0, -100.0, 1.0};
GLfloat whitelight[]={1.0, 1.0, 1.0, 1.0};
GLfloat amblight[]={0.2, 0.2, 0.2, 1.0};
GLfloat blacklight[]={0.0, 0.0, 0.0, 1.0};
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amblight);
GLfloat whitelight1[]={0, 0, 0, 1.0};
glLightfv(GL_LIGHT0, GL_AMBIENT, blacklight);
glLightfv(GL_LIGHT0, GL_SPECULAR, whitelight);
glLightfv(GL_LIGHT0, GL_DIFFUSE, whitelight);
glLightfv(GL_LIGHT0, GL_POSITION, L0position);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
}
void orientMe(float ang) {
lx = sin(ang);
lz = -cos(ang);
glLoadIdentity();
gluLookAt(x, y, z,
x + lx,y + ly,z + lz,
0.0f,1.0f,0.0f);
}
void moveMeFlat(int i) {
x = x + i*(lx)*0.8;
z = z + i*(lz)*0.8;
glLoadIdentity();
gluLookAt(x, y, z,
x + lx,y + ly,z + lz,
0.0f,1.0f,0.0f);
}
void renderScene(void) {
if (deltaMove)
moveMeFlat(deltaMove);
if (deltaAngle) {
angle += deltaAngle;
orientMe(angle);
}
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
setLight();
glEnable(GL_COLOR_MATERIAL);
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
glMaterialfv(GL_FRONT, GL_AMBIENT, no_mat);
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, no_mat);
glMaterialfv(GL_FRONT, GL_SHININESS, no_shininess);
glMaterialfv(GL_FRONT, GL_EMISSION, no_mat);
glColor3f(0.9f, 0.9f, 0.9f);
glBegin(GL_QUADS);
glVertex3f(-500.0f, 0.0f, -500.0f);
glVertex3f(-500.0f, 0.0f, 500.0f);
glVertex3f( 500.0f, 0.0f, 500.0f);
glVertex3f( 500.0f, 0.0f, -500.0f);
glEnd();
//glDisable(GL_COLOR_MATERIAL);
//princess
glEnable( GL_TEXTURE_2D );
glBindTexture (GL_TEXTURE_2D, princessTexture);
glPushMatrix();
glTranslatef(10,7,-90);
glColor3f(1.0f,1.0f,1.0f);
glBegin(GL_QUADS);
glTexCoord2f(0,0);
glVertex3f(-5.0f, 5.0f, 0.0f);
glTexCoord2f(1,0);
glVertex3f(-5.0f,-5.0f, 0.0f);
glTexCoord2f(1,1);
glVertex3f( 5.0f,-5.0f, 0.0f);
glTexCoord2f(0,1);
glVertex3f( 5.0f, 5.0f, 0.0f);
glEnd();
glPopMatrix();
glColor3f(1.0f,1.0f,1.0f);
glPushMatrix();
glTranslatef(-5,15,-95);
glutSolidCube(10);
glPopMatrix();
glDisable( GL_TEXTURE_2D );
glutSwapBuffers();
}
void pressKey(int key, int x, int y) {
switch (key) {
case GLUT_KEY_LEFT : deltaAngle = -0.02f;break;
case GLUT_KEY_RIGHT : deltaAngle = 0.02f;break;
case GLUT_KEY_UP : deltaMove = 1;break;
case GLUT_KEY_DOWN : deltaMove = -1;break;
}
}
void releaseKey(int key, int x, int y) {
switch (key) {
case GLUT_KEY_LEFT : if (deltaAngle < 0.0f)
deltaAngle = 0.0f;
break;
case GLUT_KEY_RIGHT : if (deltaAngle > 0.0f)
deltaAngle = 0.0f;
break;
case GLUT_KEY_UP : if (deltaMove > 0)
deltaMove = 0;
break;
case GLUT_KEY_DOWN : if (deltaMove < 0)
deltaMove = 0;
break;
}
}
void initWindow() {
glutIgnoreKeyRepeat(1);
glutSpecialFunc(pressKey);
glutSpecialUpFunc(releaseKey);
glutDisplayFunc(renderScene);
glutIdleFunc(renderScene);
glutReshapeFunc(changeSize);
glShadeModel (GL_SMOOTH);
glEnable(GL_LIGHTING);
glEnable(GL_DEPTH_TEST);
glEnable(GL_NORMALIZE);
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowPosition(100,100);
glutInitWindowSize(640,360);
glutCreateWindow("2");
initWindow();
princessTexture = LoadTexture("Princess_Peach_Stock_Art.png");
glutMainLoop();
return(0);
}
A piece of advice: Use up-to-date libraries and learn how to write shader code. Also, a scripting language like Python can help a lot. If its garbage collection is not an option, use modern C++.