OpenGL Won't Change Texture - c++

My textures wont change and i'm not sure why. This my Texture Loader.h
class TextureLoader
{
private:
GLuint* Texture;
std::map<std::string, GLuint*> TextureMap;
public:
TextureLoader(){};
~TextureLoader()
{
delete Texture;
}
bool LoadTexture(std::string Source);
GLuint* GetImage(std::string TextureID);
bool CheckTextureExsist(std::string TextureID);
};
This is the CPP.
bool TextureLoader::LoadTexture(std::string Source)
{
//Bind the texture to load in.
Texture = new GLuint;
glGenTextures (1, Texture);
glBindTexture (GL_TEXTURE_CUBE_MAP, *Texture);
glTexParameteri (GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri (GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri (GL_TEXTURE_2D,GL_TEXTURE_WRAP_R,GL_CLAMP_TO_EDGE);
glTexParameteri (GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);
glTexParameteri (GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP_TO_EDGE);
//Width, Height and Components of the image.
int x, y, n;
//Set pixel format
int force_channels = 4;
//Load data into the char.
unsigned char* image_data = stbi_load (
Source.c_str(), &x, &y, &n, force_channels);
//Check too see if the image loaded.
if (!image_data) {
fprintf (stderr, "ERROR: could not load %s\n", Source);
return false;
}
//Copy the image data to the selected target.
glTexImage2D (
GL_TEXTURE_2D,
0,
GL_RGBA,
x,
y,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
image_data
);
free (image_data);
TextureMap.insert(std::pair<std::string, GLuint*>(Source,Texture));
return true;
}
GLuint* TextureLoader::GetImage(std::string TextureID)
{
return TextureMap.find(TextureID)->second;
}
bool TextureLoader::CheckTextureExsist(std::string TextureID)
{
if(TextureMap.find(TextureID) == TextureMap.end())
{
return false;
}
else
return true;
}
This is how i am drawing.
glBindTexture(GL_TEXTURE_2D, *TextureID);
glMaterialfv(GL_FRONT , GL_AMBIENT, Ambient);
glMaterialfv(GL_FRONT , GL_DIFFUSE, Diffuse);
glMaterialfv(GL_FRONT , GL_SPECULAR, Specular);
glMaterialf(GL_FRONT , GL_SHININESS, Shininess);
glVertexPointer(3,GL_FLOAT,0,&Vertices[0]);
glNormalPointer(GL_FLOAT,0,&Normals[0]);
glTexCoordPointer(2,GL_FLOAT,0,&TextureCoords[0]);
glPushMatrix();
glScalef(Scale[0],Scale[1],Scale[2]);
glTranslatef(Translate[0],Translate[1],Translate[2]);
glRotatef(Rotate[0],Rotate[1],Rotate[2],Rotate[3]);
glDrawArrays(GL_TRIANGLES, 0,(GLsizei)(Vertices.size()/3));
glPopMatrix();
glBindTexture(GL_TEXTURE_2D, NULL);
The TextureID gets passed the pointer, of the texture handle . The handle does change during run time to the different handles but it does draws the last texture that i loaded in, regardless of texture handle.

The problem is binding to GL_TEXTURE_CUBE_MAP in your LoadTexture function:
glBindTexture (GL_TEXTURE_CUBE_MAP, *Texture);
Change that to
glBindTexture(GL_TEXTURE_2D, *Texture);
I would also suggest to use GLuint instead of a GLuint* and store that into the map. The only reason glGenTextures takes a pointer is because it can also output to an array of GLuint.

Related

Opengl glBindTexture Using Last Texture Loaded

opengl uses only the last texture loaded and I'm not sure why. Here is my code:
GLuint loadTex(const char* c) {
GLuint temp = SOIL_load_OGL_texture(
c,
SOIL_LOAD_AUTO,
SOIL_CREATE_NEW_ID,
SOIL_FLAG_MIPMAPS | SOIL_FLAG_INVERT_Y | SOIL_FLAG_NTSC_SAFE_RGB | SOIL_FLAG_COMPRESS_TO_DXT
);
if (0 == temp)
{
printf("SOIL loading error: '%s'\n", SOIL_last_result());
//return 0;
}
//glGenTextures(1, &temp);
glBindTexture(GL_TEXTURE_2D, temp);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
return temp;
}
void drawObject(std::vector<Level::Triangle> faces, GLuint &resID, double x, double y, double z ){
glColor3f(1, 1, 1);
//glColor3f(0, 1, 0);
glTranslatef(x, y, z);
glBegin(GL_TRIANGLES);
//glBindTexture(GL_TEXTURE_2D, resID);
//glActiveTexture(GL_TEXTURE1);
for (int i = 0; i < faces.size(); i++){
Level::Triangle t = faces[i];
glTexCoord2f(t.p1.tx, t.p1.ty);
//glTexCoord2f(0.0, 0.0);
glVertex3f(t.p1.x, t.p1.y, t.p1.z);
glTexCoord2f(t.p2.tx, t.p2.ty);
//glTexCoord2f(0.0, 1.0);
glVertex3f(t.p2.x, t.p2.y, t.p2.z);
glTexCoord2f(t.p3.tx, t.p3.ty);
//glTexCoord2f(1.0, 1.0);
glVertex3f(t.p3.x, t.p3.y, t.p3.z);
}
glEnd();
glTranslatef(-x, -y, -z);
}
The textures are loaded into a c++ vector class array and then passed to the drawObject function. Only the last texture loaded is used when drawing objects, I'm not sure why. And yes, each time SOIL loads a texture it is assigned a new GLuint, and yes the textures are loaded prior to use.
glBegin(GL_TRIANGLES);
//glBindTexture(GL_TEXTURE_2D, resID);
//glActiveTexture(GL_TEXTURE1);
The only functions you can call in between glBegin and glEnd are vertex submission calls, like glColor*, glTexCoord*, glVertex*, and a few others. glBindTexture and glActiveTexture must be called before glBegin.
Also, you have the order of glActiveTexture and glBindTexture incorrect; you need to select the texture you want to bind to with glActiveTexture first, then actually bind it with glBindTexture.
(I also suggest you don't use glBegin and friends at all; learn to use vertex buffer objects, vertex array objects, and shaders, as glBegin, et.al. are deprecated and don't scale)

OpenGL Texturing, no error but grey

Trying to colour terrain points based on texture colour (currently hard coded to vec2(0.5, 0.5) for test purposes - which should be light blue) but all the points are grey. glGetError returns 0 throughout the whole process. I think I might be doing the render process wrong or have a problem with my shaders(?)
Vertex Shader:
void main(){
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
Fragment Shader:
uniform sampler2D myTextureSampler;
void main(){
gl_FragColor = texture2D(myTextureSampler, vec2(0.5, 0.5));
}
Terrain Class:
class Terrain
{
public:
Terrain(GLuint pProgram, char* pHeightmap, char* pTexture){
if(!LoadTerrain(pHeightmap))
{
OutputDebugString("Loading terrain failed.\n");
}
if(!LoadTexture(pTexture))
{
OutputDebugString("Loading terrain texture failed.\n");
}
mProgram = pProgram;
mTextureLocation = glGetUniformLocation(pProgram, "myTextureSampler");
};
~Terrain(){};
void Draw()
{
glEnableClientState(GL_VERTEX_ARRAY); // Uncommenting this causes me to see nothing at all
glBindBuffer(GL_ARRAY_BUFFER, mVBO);
glVertexPointer(3, GL_FLOAT, 0, 0);
glEnable( GL_TEXTURE_2D );
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, mBMP);
glProgramUniform1i(mProgram, mTextureLocation, 0);
GLenum a = glGetError();
glPointSize(5.0f);
glDrawArrays(GL_POINTS, 0, mNumberPoints);
a = glGetError();
glBindBuffer(GL_ARRAY_BUFFER, 0);
glDisable( GL_TEXTURE_2D );
glDisableClientState(GL_VERTEX_ARRAY);
}
private:
GLuint mVBO, mBMP, mUV, mTextureLocation, mProgram;
int mWidth;
int mHeight;
int mNumberPoints;
bool LoadTerrain(char* pFile)
{
/* Definitely no problem here - Vertex data is fine and rendering nice and dandy */
}
// TEXTURES MUST BE POWER OF TWO!!
bool LoadTexture(char *pFile)
{
unsigned char header[54]; // Each BMP file begins by a 54-bytes header
unsigned int dataPos; // Position in the file where the actual data begins
unsigned int width, height;
unsigned int imageSize;
unsigned char * data;
FILE * file = fopen(pFile, "rb");
if(!file)
return false;
if(fread(header, 1, 54, file) != 54)
{
fclose(file);
return false;
}
if ( header[0]!='B' || header[1]!='M' )
{
fclose(file);
return false;
}
// Read ints from the byte array
dataPos = *(int*)&(header[0x0A]);
imageSize = *(int*)&(header[0x22]);
width = *(int*)&(header[0x12]);
height = *(int*)&(header[0x16]);
// Some BMP files are misformatted, guess missing information
if (imageSize==0) imageSize=width*height*3; // 3 : one byte for each Red, Green and Blue component
if (dataPos==0) dataPos=54; // The BMP header is done that way
// Create a buffer
data = new unsigned char [imageSize];
// Read the actual data from the file into the buffer
fread(data,1,imageSize,file);
//Everything is in memory now, the file can be closed
fclose(file);
// Create one OpenGL texture
glGenTextures(1, &mBMP);
// "Bind" the newly created texture : all future texture functions will modify this texture
glBindTexture(GL_TEXTURE_2D, mBMP);
// Give the image to OpenGL
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_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
delete [] data;
data = 0;
return true;
}
};
Answering own question incase anyone has a similar problem:
I had tested this with multiple images - but it turns out theres a bug in my graphics application of choice; which has been exporting 8-bit Bitmap's even though I explicitally told it to export 24-bit Bitmap's. So basically - reverting back to MS Paint solved my solution. 3 cheers for MS Paint.

OpenGL renders texture all white

I'm attempting to render a .png image as a texture. However, all that is being rendered is a white square.
I give my texture a unique int ID called texID, read the pixeldata into a buffer 'image' (declared in the .h file). I load my pixelbuffer, do all of my OpenGL stuff and bind that pixelbuffer to a texture for OpenGL. I then draw it all using glDrawElements.
Also I initialize the texture with a size of 32x32 when its contructor is called, therefore i doubt it is related to a power of two size issue.
Can anybody see any mistakes in my OpenGL GL_TEXTURE_2D setup that might give me a block white square.
#include "Texture.h"
Texture::Texture(int width, int height, string filename)
{
const char* fnPtr = filename.c_str(); //our image loader accepts a ptr to a char, not a string
printf(fnPtr);
w = width; //give our texture a width and height, the reason that we need to pass in the width and height values manually
h = height;//UPDATE, these MUST be P.O.T.
unsigned error = lodepng::decode(image,w,h,fnPtr);//lodepng's decode function will load the pixel data into image vector
//display any errors with the texture
if(error)
{
cout << "\ndecoder error " << error << ": " << lodepng_error_text(error) <<endl;
}
for(int i = 0; i<image.size(); i++)
{
printf("%i,", image.at(i));
}
printf("\nImage size is %i", image.size());
//image now contains our pixeldata. All ready for OpenGL to do its thing
//let's get this texture up in the video memory
texGLInit();
}
void Texture::texGLInit()
{
//WHERE YOU LEFT OFF: glGenTextures isn't assigning an ID to textures. it stays at zero the whole time
//i believe this is why it's been rendering white
glGenTextures(1, &textures);
printf("\ntexture = %u", textures);
glBindTexture(GL_TEXTURE_2D, textures);//evrything we're about to do is about this texture
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
//glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
//glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
//glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
//glDisable(GL_COLOR_MATERIAL);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8,w,h,0, GL_RGBA, GL_UNSIGNED_BYTE, &image);
//we COULD free the image vectors memory right about now.
}
void Texture::draw(point centerPoint, point dimensions)
{
glEnable(GL_TEXTURE_2D);
printf("\nDrawing block at (%f, %f)",centerPoint.x, centerPoint.y);
glBindTexture(GL_TEXTURE_2D, textures);//bind the texture
//create a quick vertex array for the primitive we're going to bind the texture to
printf("TexID = %u",textures);
GLfloat vArray[8] =
{
centerPoint.x-(dimensions.x/2), centerPoint.y-(dimensions.y/2),//bottom left i0
centerPoint.x-(dimensions.x/2), centerPoint.y+(dimensions.y/2),//top left i1
centerPoint.x+(dimensions.x/2), centerPoint.y+(dimensions.y/2),//top right i2
centerPoint.x+(dimensions.x/2), centerPoint.y-(dimensions.y/2)//bottom right i3
};
//create a quick texture array (we COULD create this on the heap rather than creating/destoying every cycle)
GLfloat tArray[8] =
{
0.0f,0.0f, //0
0.0f,1.0f, //1
1.0f,1.0f, //2
1.0f,0.0f //3
};
//and finally.. the index array...remember, we draw in triangles....(and we'll go CW)
GLubyte iArray[6] =
{
0,1,2,
0,2,3
};
//Activate arrays
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
//Give openGL a pointer to our vArray and tArray
glVertexPointer(2, GL_FLOAT, 0, &vArray[0]);
glTexCoordPointer(2, GL_FLOAT, 0, &tArray[0]);
//Draw it all
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_BYTE, &iArray[0]);
//glDrawArrays(GL_TRIANGLES,0,6);
//Disable the vertex arrays
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisable(GL_TEXTURE_2D);
//done!
/*glBegin(GL_QUADS);
glTexCoord2f(0.0f,0.0f);
glVertex2f(centerPoint.x-(dimensions.x/2), centerPoint.y-(dimensions.y/2));
glTexCoord2f(0.0f,1.0f);
glVertex2f(centerPoint.x-(dimensions.x/2), centerPoint.y+(dimensions.y/2));
glTexCoord2f(1.0f,1.0f);
glVertex2f(centerPoint.x+(dimensions.x/2), centerPoint.y+(dimensions.y/2));
glTexCoord2f(1.0f,0.0f);
glVertex2f(centerPoint.x+(dimensions.x/2), centerPoint.y-(dimensions.y/2));
glEnd();*/
}
Texture::Texture(void)
{
}
Texture::~Texture(void)
{
}
I'll also include the main class' init, where I do a bit more OGL setup before this.
void init(void)
{
printf("\n......Hello Guy. \n....\nInitilising");
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(0,XSize,0,YSize);
glEnable(GL_TEXTURE_2D);
myBlock = new Block(0,0,offset);
glClearColor(0,0.4,0.7,1);
glLineWidth(2); // Width of the drawing line
glMatrixMode(GL_MODELVIEW);
glDisable(GL_DEPTH_TEST);
printf("\nInitialisation Complete");
}
Update: adding in the main function where I first setup my OpenGL window.
int main(int argc, char** argv)
{
glutInit(&argc, argv); // GLUT Initialization
glutInitDisplayMode(GLUT_RGBA|GLUT_DOUBLE); // Initializing the Display mode
glutInitWindowSize(800,600); // Define the window size
glutCreateWindow("Gem Miners"); // Create the window, with caption.
printf("\n========== McLeanTech Systems =========\nBecoming Sentient\n...\n...\n....\nKILL\nHUMAN\nRACE \n");
init(); // All OpenGL initialization
//-- Callback functions ---------------------
glutDisplayFunc(display);
glutKeyboardFunc(mykey);
glutSpecialFunc(processSpecialKeys);
glutSpecialUpFunc(processSpecialUpKeys);
//glutMouseFunc(mymouse);
glutMainLoop(); // Loop waiting for event
}
Here's the usual checklist for whenever textures come out white:
OpenGL context created and being bound to current thread when attemting to load texture?
Allocated texture ID using glGenTextures?
Are the parameters format and internal format to glTex[Sub]Image… valid OpenGL tokens allowed as input for this function?
Is mipmapping being used?
YES: Supply all mipmap layers – optimally set glTexParameteri GL_TEXTURE_BASE_LEVEL and GL_TEXTURE_MAX_LEVEL, as well as GL_TEXTURE_MIN_LOD and GL_TEXTURE_MAX_LOG.
NO: Turn off mipmap filtering by setting glTexParameteri GL_TEXTURE_MIN_FILTER to GL_NEAREST or GL_LINEAR.

OpenGL Applying Texture to Tessellation

I'm trying to take a concave polygon and apply an image to it as a texture. The polygon can have multiple contours, both internal holes and external "islands". It can be any shape, but will be smaller than the image and will fit inside it. It does not necessarily touch the edges of the image.
I've successfully displayed the tessellated polygon, and textured a simple square, but can't get the two to work together.
Here's how I'm loading the texture:
GLuint texture;
int width, height;
BYTE * data;
FILE * file;
// open texture data
file = fopen( filename, "rb" );
if ( file == NULL ) return 0;
// allocate buffer
width = 256;
height = 256;
data = (BYTE *)malloc( width * height * 3 );
// read texture data
fread( data, width * height * 3, 1, file );
fclose( file );
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, wrap ? GL_REPEAT : GL_CLAMP );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrap ? GL_REPEAT : GL_CLAMP );
gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width,height, GL_RGB, GL_UNSIGNED_BYTE, data );
free( data );
return texture;
Here's the tessellation function:
GLuint tessellate1()
{
GLuint id = glGenLists(1); // create a display list
if(!id) return id; // failed to create a list, return 0
GLUtesselator *tess = gluNewTess(); // create a tessellator
if(!tess) return 0; // failed to create tessellation object, return 0
GLdouble quad1[4][3] = { {-1,3,0}, {0,0,0}, {1,3,0}, {0,2,0} };
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, GLTexture::LoadTextureRAW("texture.raw", true));
// register callback functions
gluTessCallback(tess, GLU_TESS_BEGIN, (void (CALLBACK *)())tessBeginCB);
gluTessCallback(tess, GLU_TESS_END, (void (CALLBACK *)())tessEndCB);
gluTessCallback(tess, GLU_TESS_ERROR, (void (CALLBACK *)())tessErrorCB);
gluTessCallback(tess, GLU_TESS_VERTEX, (void (CALLBACK *)())tessVertexCB);
glNewList(id, GL_COMPILE);
glColor3f(1,1,1);
gluTessBeginPolygon(tess, 0); // with NULL data
gluTessBeginContour(tess);
gluTessVertex(tess, quad1[0], quad1[0]);
gluTessVertex(tess, quad1[1], quad1[1]);
gluTessVertex(tess, quad1[2], quad1[2]);
gluTessVertex(tess, quad1[3], quad1[3]);
gluTessEndContour(tess);
gluTessEndPolygon(tess);
glEndList();
gluDeleteTess(tess); // delete after tessellation
glDisable(GL_TEXTURE_2D);
setCamera(0, 0, 5, 0, 0, 0);
return id; // return handle ID of a display list
}
Here's the tessellation vertex callback function:
// cast back to double type
const GLdouble *ptr = (const GLdouble*)data;
double dImageX = -1, dImageY = -1;
//hardcoded extents of the polygon for the purposes of testing
int minX = 607011, maxX = 616590;
int minY = 4918219, maxY = 4923933;
//get the % coord of the texture for a poly vertex. Assumes image and poly bounds are the same for the purposes of testing
dImageX = (ptr[0] - minX) / (maxX - minX);
dImageY = (ptr[1] - minY) / (maxY - minY);
glTexCoord2d(dImageX, dImageY);
glVertex2d(ptr[0], ptr[1]);
And here's the display callback:
void displayCB()
{
// clear buffer
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
// save the initial ModelView matrix before modifying ModelView matrix
glPushMatrix();
// tramsform camera
glTranslatef(0, 0, cameraDistance);
glRotatef(cameraAngleX, 1, 0, 0); // pitch
glRotatef(cameraAngleY, 0, 1, 0); // heading
// draw meshes
glCallList(listId1); //id of the tessellated poly
// draw info messages
showInfo();
glPopMatrix();
glutSwapBuffers();
}
The results of this are a correctly drawn polygon with no texture applied.
// init
glGenTextures( 1, &texture );
// vertex callback
glBindTexture(GL_TEXTURE_2D, 1);
I don't think the first ID returned by glGenTextures() is required to be 1.
Try using texture instead of 1 in your glBindTexture() call.
Also, there's really no reason to enable texturing and re-bind the texture for every vertex. Just do it once before you call into the tesselator.
You're not capturing the texture binding and Enable inside the display list, so it's not going to be taken into account when you replay it. So, either:
Capture the BindTexture and Enable inside the display list, or
BindTexture and Enable(TEXTURE_2D) before calling CallList
The problem was the glDisable(GL_TEXTURE_2D) call in the tessellation function. After removing it, the texture was applied correctly.

Open GL texturing , texture coordinates are incorrect to what is rendered

I'm rendering a scene using opengl with textures loaded using some sample code and the FreeImage API.
Here is a link to what i'm seeing
[Image Removed]
I can confirm that all texture coordinates are provided to glTexCoord2f between 0.0f and 1.0f as required along with the vertex coordinates.
Each of the rendered triangles appears to have the full texture pasted across it (and repeated) not the area of the texture specified by the coordinates.
The texture is 1024x1024.
This is the function for loading the texture
bool loadImageToTexture(const char* image_path, unsigned int &handle)
{
if(!image_path)
return false;
FREE_IMAGE_FORMAT fif = FIF_UNKNOWN;
FIBITMAP* dib(0);
BYTE* bits(0);
unsigned int width(0), height(0);
//open the file
fif = FreeImage_GetFileType(image_path, 0);
if(fif == FIF_UNKNOWN)
fif = FreeImage_GetFIFFromFilename(image_path);
if(fif == FIF_UNKNOWN)
return false;
if(FreeImage_FIFSupportsReading(fif))
dib = FreeImage_Load(fif, image_path);
if(!dib)
return false;
//is the file of the correct type
FREE_IMAGE_COLOR_TYPE type = FreeImage_GetColorType(dib);
if(FIC_RGBALPHA != type)
{
//convert to type
FIBITMAP* ndib = FreeImage_ConvertTo32Bits(dib);
dib = ndib;
}
//get data for glTexImage2D
bits = FreeImage_GetBits(dib);
width = FreeImage_GetWidth(dib);
height = FreeImage_GetHeight(dib);
if((bits == 0) || (width == 0) || (height == 0))
return false;
//create the texture in open gl
glGenTextures(1, &handle);
glBindTexture(GL_TEXTURE_2D, handle);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glPixelStorei(GL_TEXTURE_2D, 4);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height,
0, GL_RGBA, GL_UNSIGNED_BYTE, bits);
//unload the image now loaded
FreeImage_Unload(dib);
return true;
}
These are the functions for rendering
inline void glTexture(float textureSize, float t, float u)
{
glTexCoord2f(u/textureSize, (textureSize - t)/textureSize);
}
void processTriangle(const btVector3* triangle, const textureCoord* tc, const btVector3& normal,
const int partId, const int triangleIndex, const bool wireframe)
{
if(wireframe)
{
glBegin(GL_LINES);
glColor3f(1, 0, 0);
glVertex3d(triangle[0].getX(), triangle[0].getY(), triangle[0].getZ());
glVertex3d(triangle[1].getX(), triangle[1].getY(), triangle[1].getZ());
glColor3f(0, 1, 0);
glVertex3d(triangle[2].getX(), triangle[2].getY(), triangle[2].getZ());
glVertex3d(triangle[1].getX(), triangle[1].getY(), triangle[1].getZ());
glColor3f(0, 0, 1);
glVertex3d(triangle[2].getX(), triangle[2].getY(), triangle[2].getZ());
glVertex3d(triangle[0].getX(), triangle[0].getY(), triangle[0].getZ());
glEnd();
}
else
{
glBegin(GL_TRIANGLES);
glColor3f(1, 1, 1);
//Normals are per triangle
glNormal3f(normal.getX(), normal.getY(), normal.getZ());
glTexture(1024.0f, tc[0].t, tc[0].u);
glVertex3d(triangle[0].getX(), triangle[0].getY(), triangle[0].getZ());
glTexture(1024.0f, tc[1].t, tc[1].u);
glVertex3d(triangle[1].getX(), triangle[1].getY(), triangle[1].getZ());
glTexture(1024.0f, tc[2].t, tc[2].u);
glVertex3d(triangle[2].getX(), triangle[2].getY(), triangle[2].getZ());
glEnd();
}
}
void processAllTriangles(const btVector3& worldBoundsMin, const btVector3& worldBoundsMax)
{
btVector3 triangle[3];
textureCoord tc[3];
//go through the index list build triangles and draw them
unsigned int k = 0;
for(unsigned int i = 0; i<dVertices.size(); i+=3, k++)
{
//first vertex
triangle[0] = dVertices[i];
tc[0] = dTexCoords[i];
//second vertex
triangle[1] = dVertices[i+1];
tc[1] = dTexCoords[i+1];
//third vertex
triangle[2] = dVertices[i+2];
tc[2] = dTexCoords[i+2];
processTriangle(triangle, tc, dNormals[k], 0, 0, false);
}
}
//draw the world given the players position
void render(btScalar* m, const btCollisionShape* shape, const btVector3& color, int debugMode,
const btVector3& worldBoundsMin, const btVector3& worldBoundsMax)
{
//render the world using the generated OpenGL lists
//enable and specify pointers to vertex arrays
glPushMatrix();
glMultMatrixf(m);
glMatrixMode(GL_TEXTURE);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glEnable(GL_TEXTURE_2D);
glShadeModel(GL_SMOOTH);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glBindTexture(GL_TEXTURE_2D, m_texturehandle);
processAllTriangles(worldBoundsMin, worldBoundsMax);
glPopMatrix();
}
I'm working in a larger code base and texturing is being done differently in different areas mean state from those other textured objects was not being disabled.
Before per vertex texturing is done make sure to turn off other varieties of texturing.
glDisable(GL_TEXTURE_GEN_S);
glDisable(GL_TEXTURE_GEN_T);
glDisable(GL_TEXTURE_GEN_R);