In this way, outputting one obj file each works well.
But if I try to represent these two objs revolving around the center sun at the same time, I get an error.
It looks like it's working well at first, and then the texture disappears. And the result window is forced to shut down.
void RenderScene(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// World Transfrom
glPushMatrix();
glLoadIdentity();
//glTranslatef (0.0f, 0.0f, -300.0f);
///////////////////Drawing//////////////////////////////////////////////////////
// Figure0 Draw
glPushMatrix();
glLoadIdentity();
glColor3f(1.0f, 0.0f, 0.0f);
glutSolidSphere(10, 15, 15);
glPopMatrix();
// Figure1 Draw
glPushMatrix();
glLoadIdentity();
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glRotatef(0.0f, 0.0f, 1.0f, 0.0f);
glRotatef(Sphere1_degree, 0.0f, 1.0f, 0.0f);
glTranslatef(70.0f, 0.0f, 0.0f);
glColor3f(0.0f, 1.0f, 0.0f);
_mesh = new Mesh("obj\\Earth_2K.obj", "obj\\Diffuse_2K_Earth.png");
_mesh->drawSolid(_smoothing);
glPopMatrix();
// Figure2 Draw
glPushMatrix();
glLoadIdentity();
glRotatef(-45.0f, 0.0f, 0.0f, 1.0f);
glRotatef(Sphere2_degree, 0.0f, 1.0f, 0.0f);
glTranslatef(60.0f, 0.0f, 0.0f);
glColor3f(0.0f, 0.0f, 1.0f);
_mesh = new Mesh("obj\\Moon 2K.obj", "obj\\Diffuse_2K_Moon.png");
_mesh->drawSolid(_smoothing);
glPopMatrix();
////////////////////////////////////////////////////////////////////////////////
glPopMatrix();
glutSwapBuffers();
}
This code is a function that outputs and moves obj. The _mesh over there is a class object for me to load the obj file. DrawSolid is an expression of a smoothing method. I think the usage of glPushMatrix and glPopMatrix is wrong in that code, but I don't know how to fix it. Why is that happening?
Additional Description
This code is Mesh class
class Mesh
{
public:
vector<Face*> _faces;
vector<Vertex*> _vertices;
Vec3<double> _minBound;
Vec3<double> _maxBound;
vector<Texture*> _textureCoords;
GLuint _textureIndex;
public:
Mesh();
Mesh(char* obj, char* texture) {
open(obj);
loadTexture(texture, _textureIndex);
}
Mesh(char* obj) {
open(obj);
}
~Mesh();
public:
void makeList(void);
void open(char* file);
void loadTexture(char* file, GLuint& texture_index);
void computeNormal(void);
void moveToCenter(double scale = 1.0);
public:
void drawWire(void);
void drawPoint(void);
void drawSolid(bool smoothing);
};
When a Mesh class object is created, it reads the obj file and the texture file.
void Mesh::open(char* file)
{
FILE* fp;
char buffer[100] = { 0 };
Vec3<double> pos;
int index[4], tex[4], empty[4];
int id = 0;
_minBound.Set(1000000.0);
_maxBound.Set(-1000000.0);
fopen_s(&fp, file, "r");
while (fscanf(fp, "%s %lf %lf %lf", buffer, &pos[0], &pos[1], &pos[2]) != EOF)
{
// v 0.2 0.3 0.1
// vt
if (buffer[0] == 'v' && buffer[1] == NULL) {
for (int i = 0; i < 3; i++) {
if (_minBound[i] > pos[i]) _minBound[i] = pos[i];
if (_maxBound[i] < pos[i]) _maxBound[i] = pos[i];
}
_vertices.push_back(new Vertex(id, pos));
}
}
// read texture coordinate of vertics
id = 0;
fseek(fp, 0, SEEK_SET);
while (fscanf(fp, "%s %lf %lf", &buffer, &pos[0], &pos[1]) != EOF) {
if (!strcmp(buffer, "vt")) {
_textureCoords.push_back(new Texture(pos[0], 1.0 - pos[1], 0.0));
}
}
// read faces
id = 0;
fseek(fp, 0, SEEK_SET);
while (fscanf(fp, "%s %d/%d/%d %d/%d/%d %d/%d/%d %d/%d/%d", &buffer, &index[0], &tex[0], &empty[0], &index[1], &tex[1], &empty[1], &index[2], &tex[2], &empty[2], &index[3], &tex[3], &empty[3]) != EOF) {
if (buffer[0] == 'f' && buffer[1] == NULL) {
auto v0 = _vertices[index[0] - 1];
auto v1 = _vertices[index[1] - 1];
auto v2 = _vertices[index[2] - 1];
_faces.push_back(new Face(id++, v0, v1, v2, _vertices[index[3] - 1], tex[0] - 1, tex[1] - 1, tex[2] - 1, tex[3] - 1));
//_faces.push_back(new Face(index++, _vertices[v_index[0] - 1], _vertices[v_index[1] - 1], _vertices[v_index[2] - 1]);
}
}
fclose(fp);
moveToCenter(10.0);
makeList();
computeNormal();
}
This code is the Open function of the Mesh class. This code reads the vertex value, the texel value, and the face value from the obj file. It is then passed over to each class object and stored in the list of class vectors and normalized.
void Mesh::drawSolid(bool smoothing) {
glPushMatrix();
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, _textureIndex);
glEnable(GL_LIGHTING);
glEnable(GL_SMOOTH)
for (auto f : _faces) {
// get texture coord
glBegin(GL_POLYGON);
if(!smoothing)
glNormal3f(f->_normal.x(), f->_normal.y(), f->_normal.z());
_textureCoords[f->_texelPos[0]];
for (int i = 0; i < 4; i++) {
auto t = _textureCoords[f->_texelPos[i]];
auto v = f->_vertices[i];
glTexCoord2f((GLfloat)t->x(), (GLfloat)t->y());
glNormal3f(v->_normal.x(), v->_normal.y(), v->_normal.z());
}
glEnd();
}
glDisable(GL_LIGHTING);
glDisable(GL_TEXTURE_2D);
glPopMatrix();
}
And here, I smoothed the normalized values.
In this code, _texelPos is an array of texel values at each face.
Additional Questions
void Mesh::loadTexture(char* file, GLuint& texture_index) {
glGenTextures(1, &texture_index);
FILE* fp;
fopen_s(&fp, file, "rb");
if (!fp) {
printf("ERROR : No %s.\n fail to bind %d\n", file, texture_index);
}
int width, height, channel;
unsigned char *image = stbi_load_from_file(fp, &width, &height, &channel, 4);
fclose(fp);
glBindTexture(GL_TEXTURE_2D, texture_index);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, image);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
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);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, GL_MODULATE);
}
This is the code that is responsible for setting the textures.
Here, glGenTextures(1, &texture_index); If I write the code like this, can I write the glBindTexture(GL_TEXTURE_2D, _textureIndex); in the RenderScene function of main cpp? Like that code down there?
// Figure1 Draw
glPushMatrix();
glLoadIdentity();
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glRotatef(0.0f, 0.0f, 1.0f, 0.0f);
glRotatef(Sphere1_degree, 0.0f, 1.0f, 0.0f);
glTranslatef(70.0f, 0.0f, 0.0f);
glBindTexture(GL_TEXTURE_2D, 1);
_mesh1->drawSolid(_smoothing);
glPopMatrix();
Do you create the mesh and load the texture in every frame? Likely you do not free the resources and run out of memory. Load the mesh and texture once, but draw them every frame
Create the meshes once before the render loop:
_mesh1 = new Mesh("obj\\Earth_2K.obj", "obj\\Diffuse_2K_Earth.png");
_mesh2 = new Mesh("obj\\Moon 2K.obj", "obj\\Diffuse_2K_Moon.png");
But draw the meshes in the RenderScene:
void RenderScene(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// [...]
_mesh1->drawSolid(_smoothing);
// [...]
_mesh2->drawSolid(_smoothing);
// [...]
}
Related
I found a useful post at this site, where some code is used to load a BMP
This code should load the header, read out infos, go further, read data, generate texture and bin it. But it doesnt work. What am I doing wrong ?
Texture Declaration :
GLuint texture[1];
BMP Loading :
void LoadTexture(char *filename)
{
FILE * file = fopen(filename,"rb");
unsigned char header[54];
unsigned int dataPos;
unsigned int imageSize;
unsigned int width, height;
fread(header,1,54,file);
dataPos = *(int*)&(header[0x0A]);
imageSize = *(int*)&(header[0x22]);
width = *(int*)&(header[0x12]);
height = *(int*)&(header[0x16]);
if (imageSize==0) {
imageSize=width*height*3;
}
if (dataPos==0) {
dataPos=54;
}
unsigned char data[imageSize];
fseek(file, SEEK_SET, 53);
fread(data,1,imageSize,file);
fclose(file);
glActiveTexture(GL_TEXTURE1);
glGenTextures(1, texture[0]);
glBindTexture(GL_TEXTURE_2D, texture[0]);
glTexImage2D(GL_TEXTURE_2D, 0,GL_RGB, width, height, 0, GL_BGR, GL_UNSIGNED_BYTE, data);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glGenerateMipmap(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, texture[0]);
}
EDIT : I printed out some values read from the header. The header seems to be read properly.
Drawing :
int DrawGLScene(GLvoid)
{
glLoadIdentity();
glEnable(GL_TEXTURE_2D);
glTranslatef(0.0f,0.0f,-5.0f);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, texture[0]);
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glEnd();
glFlush();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
return 1;
}
Finally, after browsing the internet quite a lot, I found this working example :
#include <stdlib.h>
#include <string.h>
#include <GL/glut.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <stdio.h>
#include <math.h>
GLuint texture[2];
struct Image {
unsigned long sizeX;
unsigned long sizeY;
char *data;
};
typedef struct Image Image;
#define checkImageWidth 64
#define checkImageHeight 64
GLubyte checkImage[checkImageWidth][checkImageHeight][3];
void makeCheckImage(void){
int i, j, c;
for (i = 0; i < checkImageWidth; i++) {
for (j = 0; j < checkImageHeight; j++) {
c = ((((i&0x8)==0)^((j&0x8)==0)))*255;
checkImage[i][j][0] = (GLubyte) c;
checkImage[i][j][1] = (GLubyte) c;
checkImage[i][j][2] = (GLubyte) c;
}
}
}
int ImageLoad(char *filename, Image *image) {
FILE *file;
unsigned long size; // size of the image in bytes.
unsigned long i; // standard counter.
unsigned short int planes; // number of planes in image (must be 1)
unsigned short int bpp; // number of bits per pixel (must be 24)
char temp; // temporary color storage for bgr-rgb conversion.
// make sure the file is there.
if ((file = fopen(filename, "rb"))==NULL){
printf("File Not Found : %s\n",filename);
return 0;
}
// seek through the bmp header, up to the width/height:
fseek(file, 18, SEEK_CUR);
// read the width
if ((i = fread(&image->sizeX, 4, 1, file)) != 1) {
printf("Error reading width from %s.\n", filename);
return 0;
}
//printf("Width of %s: %lu\n", filename, image->sizeX);
// read the height
if ((i = fread(&image->sizeY, 4, 1, file)) != 1) {
printf("Error reading height from %s.\n", filename);
return 0;
}
//printf("Height of %s: %lu\n", filename, image->sizeY);
// calculate the size (assuming 24 bits or 3 bytes per pixel).
size = image->sizeX * image->sizeY * 3;
// read the planes
if ((fread(&planes, 2, 1, file)) != 1) {
printf("Error reading planes from %s.\n", filename);
return 0;
}
if (planes != 1) {
printf("Planes from %s is not 1: %u\n", filename, planes);
return 0;
}
// read the bitsperpixel
if ((i = fread(&bpp, 2, 1, file)) != 1) {
printf("Error reading bpp from %s.\n", filename);
return 0;
}
if (bpp != 24) {
printf("Bpp from %s is not 24: %u\n", filename, bpp);
return 0;
}
// seek past the rest of the bitmap header.
fseek(file, 24, SEEK_CUR);
// read the data.
image->data = (char *) malloc(size);
if (image->data == NULL) {
printf("Error allocating memory for color-corrected image data");
return 0;
}
if ((i = fread(image->data, size, 1, file)) != 1) {
printf("Error reading image data from %s.\n", filename);
return 0;
}
for (i=0;i<size;i+=3) { // reverse all of the colors. (bgr -> rgb)
temp = image->data[i];
image->data[i] = image->data[i+2];
image->data[i+2] = temp;
}
// we're done.
return 1;
}
Image * loadTexture(){
Image *image1;
// allocate space for texture
image1 = (Image *) malloc(sizeof(Image));
if (image1 == NULL) {
printf("Error allocating space for image");
exit(0);
}
if (!ImageLoad("NeHe.bmp", image1)) {
exit(1);
}
return image1;
}
void myinit(void)
{
glClearColor (0.5, 0.5, 0.5, 0.0);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
Image *image1 = loadTexture();
if(image1 == NULL){
printf("Image was not returned from loadTexture\n");
exit(0);
}
makeCheckImage();
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
// Create Texture
glGenTextures(2, texture);
glBindTexture(GL_TEXTURE_2D, texture[0]);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); //scale linearly when image bigger than texture
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR); //scale linearly when image smalled than texture
glTexImage2D(GL_TEXTURE_2D, 0, 3, image1->sizeX, image1->sizeY, 0,
GL_RGB, GL_UNSIGNED_BYTE, image1->data);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
glBindTexture(GL_TEXTURE_2D, texture[1]);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
glTexImage2D(GL_TEXTURE_2D, 0, 3, checkImageWidth,
checkImageHeight, 0, GL_RGB, GL_UNSIGNED_BYTE,&checkImage[0][0][0]);
glEnable(GL_TEXTURE_2D);
glShadeModel(GL_FLAT);
}
void display(void){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glBindTexture(GL_TEXTURE_2D, texture[1]);
glutSolidTeapot(1.0);
glBindTexture(GL_TEXTURE_2D, texture[0]);
glBegin(GL_QUADS);
glTexCoord2f(0.0, 0.0);
glVertex3f(1.0, -1.0, 0.0);
glTexCoord2f(1.0, 0.0);
glVertex3f(1.0, 1.0, 0.0);
glTexCoord2f(1.0, 1.0);
glVertex3f(2.41421, 1.0, -1.41421);
glTexCoord2f(0.0, 1.0);
glVertex3f(2.41421, -1.0, -1.41421);
glEnd();
glutSwapBuffers();
}
void myReshape(int w, int h){
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 30.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -3.6);
}
void keyboard (unsigned char key, int x, int y){
switch (key) {
case 27: // “esc” on keyboard
exit(0);
break;
default: // “a” on keyboard
break;
}
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutCreateWindow("Texture Mapping - Programming Techniques");
myinit();
glutReshapeFunc (myReshape);
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutMainLoop();
return 0;
}
Review how you read data. dataPos, size and others may be set after reading the BMP. It's a relative position defined in the header of the image file.
And then review glTexImage2D(). Your are passing datainstead of dataPos.
I try to do OpenGL picking so I followed this post (OpenGL Picking on Selection Mode ) which seems to have a working solution but I can't make mine work. I have a 3D textured polygon in my scene and I would like to know when I click on it.
Here is my code :
The mouse method which launches the picking when right click :
void mousePressEvent(QGraphicsSceneMouseEvent *event)
{
if(event->button()==Qt::RightButton){
pickObjects(event->pos().x(),event->pos().y());
}
}
The pickObjects method:
#define BUFSIZE 512
void pickObjects(int x, int y)
{
GLint viewport[4];
GLint hits;
GLuint selectBuf[BUFSIZE];
glSelectBuffer (BUFSIZE, selectBuf);
glRenderMode (GL_SELECT);
glMatrixMode (GL_PROJECTION);
glPushMatrix ();
glLoadIdentity ();
glGetIntegerv (GL_VIEWPORT, viewport);
gluPickMatrix ((GLdouble) x, (GLdouble) (viewport[3] - y), 5.0, 5.0, viewport);
gluPerspective(fov, this->width() / this->height(), 0.1, 1000);
glMatrixMode(GL_MODELVIEW);
glInitNames();
makeCustomAnnot(GL_SELECT);
int hits=0;
glMatrixMode (GL_PROJECTION);
glPopMatrix ();
glMatrixMode(GL_MODELVIEW);
hits = glRenderMode (GL_RENDER);
if (hits != 0)
{
cout<<"FOUND " << hits << " hit(s)"<<endl; //ALWAYS GIVES 0 HITS
processHits(hits,selectBuf);
}
}
The processHits method :
void processHits(GLint inHits, GLuint buffer[])
{
unsigned int i, j;
GLuint names, *ptr, minZ,*ptrNames, numberOfNames;
ptr = (GLuint *) buffer;
minZ = 0xffffffff;
for (i = 0; i < inHits; i++) {
names = *ptr;
ptr++;
if (*ptr < minZ) {
numberOfNames = names;
minZ = *ptr;
ptrNames = ptr+2;
}
ptr += names+2;
}
cout << "Nearest: ";
ptr = ptrNames;
for (j = 0; j < numberOfNames; j++,ptr++) {
cout<< *ptr ;
}
}
The drawing obejct method :
void makeCustomAnnot(GLenum mode){
glEnable(GL_TEXTURE_2D);
glColor3f(1,1,1);
GLuint j=0;
QImage img("img.jpg");
img=QGLWidget::convertToGLFormat(img);
GLuint texturesAnnot[1];
glBindTexture( GL_TEXTURE_2D, texturesAnnot[0] );
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img.width(), img.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, img.bits());
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
if(mode == GL_SELECT){
glPushName (j);
}
glBegin(GL_QUADS);
glTexCoord2d(0,0);glVertex3d(x4,y4,z4);
glTexCoord2d(1,0);glVertex3d(x3,y3,z3);
glTexCoord2d(1,1);glVertex3d(x2,y2,z2);
glTexCoord2d(0,1);glVertex3d(x1,y1,z1);
glEnd();
if(mode == GL_SELECT)
glPopName ();
}
glDisable(GL_TEXTURE_2D);
}
The rendering method :
void render()
{
glEnable(GL_DEPTH_TEST);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glViewport(0,0,this->width() , this->height());
gluPerspective(fov, this->width() / this->height(), 0.1, 1000);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glRotatef(xRot / 5.0f, 1.0f, 0.0f, 0.0f);
glRotatef(yRot / 5.0f, 0.0f, 1.0f, 0.0f);
glRotatef(zRot / 5.0f, 0.0f, 0.0f, 1.0f);
glPushMatrix();
makeCustomAnnot(GL_RENDER);
glPopMatrix();
glDisable(GL_DEPTH_TEST);
}
So hits = glRenderMode (GL_RENDER); always returns 0 hits. What am I doing wrong?
So here is what I did to have it work perfectly.
The processHits method :
void processHits(GLint inHits, GLuint buffer[])
{
unsigned int i, j;
GLuint names, *ptr, minZ,*ptrNames, numberOfNames;
ptr = (GLuint *) buffer;
minZ = 0xffffffff;
for (i = 0; i < inHits; i++) {
names = *ptr;
ptr++;
if (*ptr < minZ) {
numberOfNames = names;
minZ = *ptr;
ptrNames = ptr+2;
}
ptr += names+2;
}
cout << "Nearest: ";
ptr = ptrNames;
for (j = 0; j < numberOfNames; j++,ptr++) {
cout<< *ptr ;
}
}
The drawing object method with creates the objects I need to pick :
void makeCustomAnnot(GLenum mode){
glEnable(GL_TEXTURE_2D);
glColor3f(1,1,1);
GLuint j=0;
QImage img("img.jpg");
img=QGLWidget::convertToGLFormat(img);
GLuint texturesAnnot[1];
glBindTexture( GL_TEXTURE_2D, texturesAnnot[0] );
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img.width(), img.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, img.bits());
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
if(mode == GL_SELECT)
glLoadName (j);
glBegin(GL_QUADS);
glTexCoord2d(0,0);glVertex3d(x4,y4,z4);
glTexCoord2d(1,0);glVertex3d(x3,y3,z3);
glTexCoord2d(1,1);glVertex3d(x2,y2,z2);
glTexCoord2d(0,1);glVertex3d(x1,y1,z1);
glEnd();
glDisable(GL_TEXTURE_2D);
}
The pickObjects method, identical to the rendering function but with instructions for picking :
#define BUFSIZE 512
unsigned int selectBuf[BUFSIZE];
void pickObjects(int x, int y)
{
GLint viewport[4];
GLint hits;
glSelectBuffer (BUFSIZE, selectBuf);
glRenderMode (GL_SELECT);
glMatrixMode (GL_PROJECTION);
glPushMatrix ();
glLoadIdentity ();
glGetIntegerv (GL_VIEWPORT, viewport);
gluPickMatrix ((GLdouble) x, (GLdouble) (viewport[3] - y), 5.0, 5.0, viewport);
gluPerspective(fov, this->width() / this->height(), 0.1, 1000);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glRotatef(xRot / 5.0f, 1.0f, 0.0f, 0.0f);
glRotatef(yRot / 5.0f, 0.0f, 1.0f, 0.0f);
glRotatef(zRot / 5.0f, 0.0f, 0.0f, 1.0f);
glRotatef((float)angleV, 1.0f, 0.0f, 0.0f);
glInitNames();
glPushName( 10000 );
glPushMatrix();
makeCustomAnnot(GL_SELECT);//draw scene in GL_SELECT mode to create the names
glPopMatrix();
hits = glRenderMode (GL_RENDER);//get the hits in GL_RENDER mode
if (hits != 0)
{
processHits(hits,selectBuf);
}
glPopMatrix();
glDisable(GL_DEPTH_TEST);
}
The rendering method :
void render()
{
glEnable(GL_DEPTH_TEST);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glViewport(0,0,this->width() , this->height());
gluPerspective(fov, this->width() / this->height(), 0.1, 1000);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glRotatef(xRot / 5.0f, 1.0f, 0.0f, 0.0f);
glRotatef(yRot / 5.0f, 0.0f, 1.0f, 0.0f);
glRotatef(zRot / 5.0f, 0.0f, 0.0f, 1.0f);
glRenderMode (GL_RENDER);
glPushMatrix();
makeCustomAnnot(GL_RENDER);
glPopMatrix();
glDisable(GL_DEPTH_TEST);
}
And finally hits = glRenderMode (GL_RENDER); in pickObjects method and then the processHits method return exactly the picked object.
I started with opengl texturing and everything was working well. Now I am trying to load a bmp and make white part transparent using glEnable(GL_BLEND); and glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
This is my source code:
float kSpeedForw=0.0f;
GLuint texture[1];
CCamera g_Camera;
GLfloat xrot = 0;
GLfloat yrot = 0;
GLfloat zrot = 0;
bool g_bFullScreen = true;
HWND g_hWnd;
RECT g_rRect;
HDC g_hDC;
HGLRC g_hRC;
HINSTANCE g_hInstance;
float jump = -0.1;
GLfloat LightAmbient[] = { 0.5f, 0.5f, 0.5f, 1.0f };
GLfloat LightDiffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f };
GLfloat LightPosition[] = { 0.0f, 0.0f, 2.0f, 1.0f };
void Init(HWND hWnd)
{
glEnable(GL_TEXTURE_2D); // Enable Texture Mapping
glShadeModel(GL_SMOOTH); // Enable Smooth Shading
glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background
glClearDepth(1.0f); // Depth Buffer Setup
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Really Nice Perspective Calculations
glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient); // Setup The Ambient Light
glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse); // Setup The Diffuse Light
glLightfv(GL_LIGHT1, GL_POSITION, LightPosition); // Position The Light
glEnable(GL_LIGHT1); // Enable Light One
glColor4f(1.0f, 1.0f, 1.0f, 0.5); // Full Brightness. 50% Alpha
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
g_hWnd = hWnd;
GetClientRect(g_hWnd, &g_rRect);
InitializeOpenGL(g_rRect.right, g_rRect.bottom);
g_Camera.PositionCamera(0, 1.5f, 6, 0, 1.5f, 5, 0, 1, 0);
ShowCursor(false);
}
GLuint LoadTexture(const char * filename)
{
glEnable(GL_TEXTURE_2D);
GLuint texture;
int width, height;
unsigned char * data;
FILE * file;
file = fopen(filename, "rb");
if (file == NULL) return 0;
if (filename=="Data/weed.bmp"){
width = 200;
height = 200;
}
if (filename == "Data/gun.bmp"){
width = 300;
height = 300;
}
data = (unsigned char *)malloc(width * height * 3);
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;
}
if (filename == "Data/weed.bmp"){
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);
}
if (filename == "Data/gun.bmp"){
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, 3,width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
}
return texture;
}
WPARAM MainLoop() // main function
{
MSG msg;
Init(g_hWnd);
glClearColor(0, 0, 255, 0);
while (1)
{
if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
{
if (msg.message == WM_QUIT)
break;
TranslateMessage(&msg);
DispatchMessage(&msg);
}
else if (LockFrameRate(60))
{
g_Camera.SetViewByMouse();
kSpeedForw = 0;
if (jump > -0.1)jump-=0.01;
CheckForMovement();
g_Camera.MoveCamera(kSpeedForw, jump);
RenderScene();
}
}
DeInit();
return(msg.wParam);
}
void RenderScene()
{
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glDisable(GL_BLEND);
glEnable(GL_SMOOTH);
glEnable(GL_DEPTH_TEST);
glEnable(GL_TEXTURE_2D);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
gluLookAt(g_Camera.m_vPosition.x, g_Camera.m_vPosition.y, g_Camera.m_vPosition.z,
g_Camera.m_vView.x, g_Camera.m_vView.y, g_Camera.m_vView.z,
g_Camera.m_vUpVector.x, g_Camera.m_vUpVector.y, g_Camera.m_vUpVector.z);
GLuint texture;
texture = LoadTexture("Data/weed.bmp");
glBindTexture(GL_TEXTURE_2D, texture);
glBegin(GL_QUADS);
float i = 0;
glColor3f(1,1,1);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-10 + i / 5, 0, 10 - i / 5);
glTexCoord2f(50.0f, 0.0f);
glVertex3f(-10 + i / 5, 0, -10 + i / 5);
glTexCoord2f(50.0f, 50.0f);
glVertex3f(10 - i / 5, 0, -10 + i / 5);
glTexCoord2f(0.0f, 50.0f);
glVertex3f(10 - i / 5, 0, 10 - i / 5);
glEnd();
////////////////////////////////////////////////////////////HUD
glDisable(GL_LIGHTING);
glDisable(GL_TEXTURE_2D);
glDisable(GL_DEPTH_TEST);
glDisable(GL_SMOOTH);
glEnable(GL_BLEND); // Turn Blending On
int vPort[4];
glGetIntegerv(GL_VIEWPORT, vPort);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0, vPort[2], 0, vPort[3], -1, 1);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
GLuint ruka;
ruka = LoadTexture("Data/gun.bmp");
glBindTexture(GL_TEXTURE_2D, ruka);
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f);
glVertex2f(0, 0);
glTexCoord2f(1.0f, 0.0f);
glVertex2f(450,0);
glTexCoord2f(1.0f, 1.0f);
glVertex2f(450,450);
glTexCoord2f(0.0f, 1.0f);
glVertex2f(0,450);
glEnd();
SwapBuffers(g_hDC);
}
The code works well for loading and rendering the platform(weed.bmp) and it also loads and renders gun fine. But big part of gun.bmp is white. I was hoping to get that part transparent. I was also hoping to add more HUD features, which would also need to be partly transparent.
My gun.bmp file: https://drive.google.com/file/d/0BxxlNcAI0eh9cHZGd1ZfMTFwYmM/view?usp=sharing
If you know a solution of this problem please post it. Thanks
You load image as GL_RGB, you want GL_RGBA to have an alpha channel.
Also, you need a 32 bits Bitmap (8 bits/channel × 4 channels = 32 bits).
i can't seem to load a bitmap and display it :S ... does anyone know what is wrong here? my bmp is 256 x 265 in size. I currently can only see a black screen (nothing is being shown). Any help would be appreciated!
int DrawGLScene(GLvoid) // Here's Where We Do All The Drawing
{
GLuint texture = LoadBMP("C:/Untitled.bmp");
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, texture);
glBegin(GL_QUADS);
glTexCoord2d(2.8f, 2.8f); glVertex2f(2.8f, 2.8f);
glTexCoord2d(2.8f, 2.8f); glVertex2f(2.8f, 2.8f);
glTexCoord2d(2.8f, 2.8f); glVertex2f(2.8f, 2.8f);
glTexCoord2d(2.8f, 2.8f); glVertex2f(2.8f, 2.8f);
glEnd();
glDisable(GL_TEXTURE_2D);
return TRUE; // Keep Going
}
GLuint LoadBMP(const char *fileName)
{
FILE *file;
unsigned char header[54];
unsigned int dataPos;
unsigned int size;
unsigned int width, height;
unsigned char *data;
file = fopen(fileName, "rb");
if (file == NULL)
{
MessageBox(NULL, L"Error: Invaild file path!", L"Error", MB_OK);
return false;
}
if (fread(header, 1, 54, file) != 54)
{
MessageBox(NULL, L"Error: Invaild file!", L"Error", MB_OK);
return false;
}
if (header[0] != 'B' || header[1] != 'M')
{
MessageBox(NULL, L"Error: Invaild file!", L"Error", MB_OK);
return false;
}
dataPos = (int)&(header[0x0A]);
size = (int)&(header[0x22]);
width = (int)&(header[0x12]);
height = (int)&(header[0x16]);
if (size == NULL)
size = width * height * 3;
if (dataPos == NULL)
dataPos = 54;
data = new unsigned char[size];
fread(data, 1, size, file);
fclose(file);
GLuint texture;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
return texture;
}
Of course you do not see anything, you are using the same texture coordinate for every vertex :)
Texture coordinates in OpenGL (unless you are using something like a special rectangle texture) are normalized in the range 0.0 - 1.0. Where (0.0, 0.0) represents the bottom-left corner of the image and (1.0, 1.0) represents the top-right. You should consider stretching the image over your quad exactly one time, so use a combination of all four corners for your coordinates.
Also, use glTexCoord2f (...) since you are clearly using single-precision floating-point coordinates and not double-precision.
Consider this instead:
glBegin( GL_QUADS);
glTexCoord2f (0.0f, 0.0f); glVertex2f (-1.0f, -1.0f);
glTexCoord2f (0.0f, 1.0f); glVertex2f (-1.0f, 1.0f);
glTexCoord2f (1.0f, 1.0f); glVertex2f ( 1.0f, 1.0f);
glTexCoord2f (1.0f, 0.0f); glVertex2f ( 1.0f, -1.0f);
glEnd ();
This code addresses two issues:
It will stretch your bitmap over the quad exactly one time
The vertex coordinates will cover your entire viewport
I'm making a particle fountain in openGL, I have the particles functioning properly. I decided to add a plane to make it look like they are bouncing off from it. What I'm trying to get is something like this
Unfortunately what I'm getting is this
the plain doesn't seem to be appearing at all. I tried messing with the co-ordinates and that doesn't seem to do anything. This is the image I'm using as the texture, it's a 256 X 256 24bit bmp.
I load the texture in the init function, then call it before I render the particles in the following function
void Load_Plane(){
glEnable(GL_BLEND);
glBlendFunc(GL_ONE_MINUS_SRC_ALPHA, GL_SRC_ALPHA);
glColor4f(0.0f, 0.2f, 0.2f, 0.5f);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, txPlane);
glBegin(GL_QUADS);
glNormal3f(-10.0f, 0.0f, -10.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-10.0f, 0.0f, 10.0f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f( 10.0f, 0.0f, 10.0f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f( 10.0f, 0.0f, -10.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-10.0f, 0.0f, -10.0f);
glEnd();
}
full code
// particle_fountain.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include<stdlib.h>
#include <stdio.h>
#include<Windows.h>
#include <time.h>
#include <GL\glut.h>
#include<GL\GLU.h>
#define MAX_PARTICLES 200 //max number of particles
#define MAX_BOUNCE_COUNT 5 //number of times a particle should bounce
#define MAX_PARTICLE_AGE 95
//Colours
float R = 0.8f;
float G = 0.2f;
float B = 0.0f;
float cR = 0.001f;
float cG = 0.002f;
float cB = 0.003f;
float Size = 0.02f; //size for points
GLuint txParticle;
GLuint txPlane;
struct PARTICLE {
float X,Y,Z; // Current position
float sX,sY,sZ; // Current Speed/Movement
float tX,tY,tZ; // Target Speed/Movement
float R,B,G; // Particle Colour
bool Active; // Is particle Active
int Age; // Age of the particle
int MaxAge; // Maximum Age before particle dies
int BounceCount;
} Particles[MAX_PARTICLES];
void Init_Particles();
void Activate_Particles();
void Adjust_Particles();
void Render_Particles();
bool LoadBitmapTexture(char * FileName, GLuint &texid);
void timer(int extra);
void Load_Plane();
void DrawGLscene();
void Reshape(GLsizei w, GLsizei h);
int main(int argc, char** argv){
glutInit(&argc,argv);
glutInitDisplayMode( GLUT_RGBA| GLUT_DOUBLE );
glutInitWindowSize( 640, 480 );
glutCreateWindow("Particle fountain");
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -1.0, 1.0, 1.0, 10.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, -0.9, -3.0);
Init_Particles();
glutDisplayFunc(DrawGLscene);
glutTimerFunc(0, timer, 0);
glutMainLoop();
}
void timer(int extra)
{
glutPostRedisplay();
glutTimerFunc(20, timer, 0);
}
void Load_Plane(){
glEnable(GL_BLEND);
glBlendFunc(GL_ONE_MINUS_SRC_ALPHA, GL_SRC_ALPHA);
glColor4f(0.0f, 0.2f, 0.2f, 0.5f);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, txPlane);
glBegin(GL_QUADS);
glNormal3f(-10.0f, 0.0f, -10.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-10.0f, 0.0f, 10.0f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f( 10.0f, 0.0f, 10.0f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f( 10.0f, 0.0f, -10.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-10.0f, 0.0f, -10.0f);
glEnd();
}
void DrawGLscene(){
Load_Plane();
glPushMatrix();
glScalef(1.0f, -1.0f, 1.0f);
Render_Particles();
glPopMatrix();
Render_Particles();
}
void Init_Particles(){
LoadBitmapTexture("./Particle.bmp", txParticle); //load the particle texture
LoadBitmapTexture("./Plain.bmp",txPlane); //load the plain texture
int p;
srand((int)time(NULL));
for(p=0; p<MAX_PARTICLES; p++){
Particles[p].Active = FALSE;
Particles[p].tX = 0.0f;
Particles[p].tY = -0.1f;
Particles[p].tZ = 0.0f;
}
}
void Activate_Particles(){
int p;
for(p=0; p<MAX_PARTICLES; p++){
if(!Particles[p].Active){
// Start the particle at 0,0,0 origin
Particles[p].X = 0.0f;
Particles[p].Y = 0.0f;
Particles[p].Z = 0.0f;
// The following lines set a random speed value
Particles[p].sX = (((float)((rand() % 100) + 1)) /
1000.0f) - 0.05f;
Particles[p].sY = (((float)((rand() % 100) + 50)) /
500.0f);
Particles[p].sZ = (((float)((rand() % 100) + 1)) /
1000.0f) - 0.05f;
// We also activate the particle
Particles[p].Active = true;
// Set it's Age to zero
Particles[p].Age = 0;
// We also assign a max age to the particles
Particles[p].MaxAge = MAX_PARTICLE_AGE;
// We Also reset the bouncecount to zero
Particles[p].BounceCount = 0;
//Adding the colours
Particles[p].R = R;
Particles[p].G = G;
Particles[p].B = B;
R+=cR;
G+=cG;
B+=cB;
if(R>1.0f){R=1.0f; cR=-cR;}
if(R<0.0f){R=0.0f; cR=-cR;}
if(G>1.0f){G=1.0f; cG=-cG;}
if(G<0.0f){G=0.0f; cG=-cG;}
if(B>1.0f){B=1.0f; cB=-cB;}
if(B<0.0f){B=0.0f; cB=-cB;}
return;
}
}
}
void Adjust_Particles(){
int p;
for(p=0; p<MAX_PARTICLES; p++){
// We move the speed towards the target speed by 1/20 (5%)
Particles[p].sX+= (Particles[p].tX - Particles[p].sX) / 20.0f;
Particles[p].sY+= (Particles[p].tY - Particles[p].sY) / 20.0f;
Particles[p].sZ+= (Particles[p].tZ - Particles[p].sZ) / 20.0f;
// Then we adjust the position of
// the particle by the new speed
Particles[p].X+= Particles[p].sX;
Particles[p].Y+= Particles[p].sY;
Particles[p].Z+= Particles[p].sZ;
// Now for the bounce code.
if(Particles[p].Y < 0.0f){
Particles[p].Y = 0.0f;
Particles[p].sY = -Particles[p].sY;
Particles[p].BounceCount++;
if(Particles[p].BounceCount > MAX_BOUNCE_COUNT){
Particles[p].Active = FALSE;
}
}
// And finally the age check
Particles[p].Age++;
if(Particles[p].Age > Particles[p].MaxAge){
Particles[p].Active = FALSE;
}
}
}
void Render_Particles(){
Activate_Particles();
Adjust_Particles();
glClear( GL_COLOR_BUFFER_BIT );
int p;
// Enable textures and bind our particle texture
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, txParticle);
// Disable Depth testing.
glDisable(GL_DEPTH_TEST);
// Enable blending
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_COLOR,GL_ONE);
for(p=0; p<MAX_PARTICLES; p++){
if(Particles[p].Active){
glColor4f(Particles[p].R,
Particles[p].G,
Particles[p].B, 1.0f);
glPushMatrix();
glTranslatef(Particles[p].X,
Particles[p].Y,
Particles[p].Z);
glBegin(GL_QUADS);
glNormal3f(0.0f, 0.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-Size, -Size, 0.0f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(Size, -Size, 0.0f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(Size, Size, 0.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-Size, Size, 0.0f);
glEnd();
glPopMatrix();
}
}
glEnable(GL_DEPTH_TEST);
glutSwapBuffers();
}
bool LoadBitmapTexture(char * FileName, GLuint &texid){
HBITMAP hBMP; // Handle Of The Bitmap
BITMAP BMP; // Bitmap Structure
glGenTextures(1, &texid); // Create The Texture
hBMP=(HBITMAP)LoadImage(GetModuleHandle(NULL),
FileName,
IMAGE_BITMAP, 0, 0,
LR_CREATEDIBSECTION | LR_LOADFROMFILE
);
if (!hBMP) // Does The Bitmap Exist?
return FALSE; // If Not Return False
GetObject(hBMP, sizeof(BMP), &BMP); // Get The Object
// hBMP: Handle To Graphics Object
// sizeof(BMP): Size Of Buffer For Object Information
// &BMP: Buffer For Object Information
glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
// Pixel Storage Mode (Word Alignment / 4 Bytes)
// Typical Texture Generation Using Data From The Bitmap
glBindTexture(GL_TEXTURE_2D, texid);// Bind To The Texture ID
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_LINEAR); // Linear Min Filter
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
GL_LINEAR); // Linear Mag Filter
glTexImage2D(GL_TEXTURE_2D, 0, 3, BMP.bmWidth, BMP.bmHeight,
0, GL_BGR_EXT, GL_UNSIGNED_BYTE, BMP.bmBits);
DeleteObject(hBMP); // Delete The Object
return TRUE; // Loading Was Successful
}
It could be that you're not clearing the depth buffer.
It doesn't affect any of the particles because you are disabling depth test when you render them, but when you render the plane, depth test is enabled, and since the depth buffer has not been cleared it has a spaz and doesn't render the plane.
Do
glClear(GL_DEPTH_BUFFER_BIT);
before you render the plane to clear the depth buffer.
EDIT:
This must be it-
You are calling
glClear(GL_COLOR_BUFFER_BIT);
after you render the plane. Look at your DrawGLScene function:
Load_Plane(); // you are drawing the plane here
glPushMatrix();
glScalef(1.0f, -1.0f, 1.0f);
Render_Particles(); // this function calls "glClear( GL_COLOR_BUFFER_BIT );"
// so anything that you rendered before is now removed.
glPopMatrix();
Render_Particles(); // same goes for here.
The solution would be to remove the call to glClear from your Render_Particles function,
and add it to the top of DrawGLScene:
(New DrawGLScene Code)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
Load_Plane();
glPushMatrix();
glScalef(1.0f, -1.0f, 1.0f);
Render_Particles();
glPopMatrix();
Render_Particles();
EDIT #2:
You're calling glutSwapBuffers in the Render_Particles function.
Don't call it there. Call it at the end of DrawGLScene: