OpenGL Texturing, no error but grey - c++

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.

Related

OpenGL imageSize is always zero

I wrote a simple test case to get the height of an image within a compute shader and write it to an SSBO. I've used the SSBO code before, and I know that part works fine. I used apitrace to inspect the state during the glDispatchCompute call, and I can see both the original texture and the image bound to the correct image unit. However, imageSize always returns zero (the output is all zeros, with the exception of some leftover -1s at the end because the division with the workgroup size rounds down). No OpenGL errors are thrown.
I based this test case on one of my earlier questions which included code to bind an SSBO to a compute shader (I use it here to get debug output from the compute shader).
class ComputeShaderWindow : public QOpenGLWindow {
public:
void initializeGL() {
// Create the opengl functions object
gl = context()->versionFunctions<QOpenGLFunctions_4_3_Core>();
m_compute_program = new QOpenGLShaderProgram(this);
auto compute_shader_s = fs::readFile(
"test_assets/example_compute_shader.comp");
QImage img("test_assets/input/out.png");
// Adds the compute shader, then links and binds it
m_compute_program->addShaderFromSourceCode(QOpenGLShader::Compute,
compute_shader_s);
m_compute_program->link();
m_compute_program->bind();
GLuint frame;
// Create the texture
gl->glGenTextures(1, &frame);
// Bind the texture
gl->glBindTexture(GL_TEXTURE_2D, frame);
// Fill the texture with the image
gl->glTexImage2D(GL_TEXTURE_2D,
0,
GL_RGB8,
img.width(),
img.height(),
0,
GL_BGRA,
GL_UNSIGNED_BYTE,
img.bits());
GLuint image_unit = 1;
// Get the location of the image uniform
GLuint uniform_location = gl->glGetUniformLocation(
m_compute_program->programId(),
"video_frame");
// Set location to 0 (a unique value that we choose)
gl->glUniform1i(uniform_location, image_unit);
// Bind layer of texture to image unit
gl->glBindImageTexture(image_unit,
frame,
0,
GL_FALSE,
0,
GL_READ_ONLY,
GL_RGBA8UI);
// We should only need the bit for shader image access,
// but for the purpose of this example, I set all the bits
// just to be safe
gl->glMemoryBarrier(GL_ALL_BARRIER_BITS);
// SSBO stuff to get output from the shader
GLfloat* default_values = new GLfloat[NUM_INVOCATIONS];
std::fill(default_values, default_values + NUM_INVOCATIONS, -1.0);
GLuint ssbo;
gl->glGenBuffers(1, &ssbo);
gl->glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo);
gl->glBufferData(GL_SHADER_STORAGE_BUFFER,
NUM_INVOCATIONS * sizeof(float),
&default_values[0],
GL_STATIC_DRAW);
gl->glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, ssbo);
gl->glDispatchCompute(NUM_INVOCATIONS / WORKGROUP_SIZE, 1, 1);
gl->glMemoryBarrier(GL_VERTEX_ATTRIB_ARRAY_BARRIER_BIT);
gl->glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, ssbo);
// Now read from the buffer so that we can check its values
GLfloat* read_data = (GLfloat*) gl->glMapBuffer(GL_SHADER_STORAGE_BUFFER,
GL_READ_ONLY);
std::vector<GLfloat> buffer_data(NUM_INVOCATIONS);
// Read from buffer
for (int i = 0; i < NUM_INVOCATIONS; i++) {
DEBUG(read_data[i]);
}
DEBUG("Done!");
gl->glUnmapBuffer(GL_SHADER_STORAGE_BUFFER);
assert(gl->glGetError() == GL_NO_ERROR);
}
void resizeGL(int width, int height) {
}
void paintGL() {
}
void teardownGL() {
}
private:
QOpenGLFunctions_4_3_Core* gl;
QOpenGLShaderProgram* m_compute_program;
static constexpr int NUM_INVOCATIONS = 9000;
static constexpr int WORKGROUP_SIZE = 128;
};
As for the compute shader:
#version 430 core
layout(local_size_x = 128) in;
layout(rgba8ui, binding = 1) readonly uniform uimage2D video_frame;
layout(std430, binding = 0) writeonly buffer SSBO {
float data[];
};
void main() {
uint ident = int(gl_GlobalInvocationID);
uint num_workgroups = int(gl_WorkGroupID);
// Write the height of the image into the buffer
data[ident] = float(imageSize(video_frame).y);
}
Turns out I forgot the texture parameters:
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
No clue why that breaks imageSize() calls though.

Something wrong with converting SDL surface to GL texture

I can't find my mistake, why text has not been created? When using texture instead of text I get nothing or black background with colored points, please help
GLuint texture;
SDL_Surface *text = NULL;
TTF_Font *font = NULL;
SDL_Color color = {0, 0, 0};
font = TTF_OpenFont("../test.ttf", 20);
text = TTF_RenderText_Solid(font, "Hello, SDL !!!", color);
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, text->w, text->h, 0, GL_RGB, GL_UNSIGNED_BYTE, text->pixels);
SDL_FreeSurface(text);
One thing you could add is to specify texture filters, e.g.
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
Few things you have to check first
is the font loaded properly? check if "font == NULL", maybe your
font path is wrong
is the shader (if you use a shader) setup properly?
My guess is that you set the wrong pixel format type in glTexImage2D cause random color dots apear on your texture
Below is my code that load image via SDL_image for OpenGL use, I think it would be a good start to figure out what step you missed or forgot.
BTW, this code is not perfect. The types of pixel format is more than four (like index color) and I only handle some of them.
/*
* object_, originalWidth_ and originalHeight_ are private variables in
* this class, don't panic.
*/
void
Texture::Load(string filePath, GLint minMagFilter, GLint wrapMode)
{
SDL_Surface* image;
GLenum textureFormat;
GLint bpp; //Byte Per Pixel
/* Load image file */
image = IMG_Load(filePath.c_str());
if (image == nullptr) {
string msg("IMG error: ");
msg += IMG_GetError();
throw runtime_error(msg.c_str());
}
/* Find out pixel format type */
bpp = image->format->BytesPerPixel;
if (bpp == 4) {
if (image->format->Rmask == 0x000000ff)
textureFormat = GL_RGBA;
else
textureFormat = GL_BGRA;
} else if (bpp == 3) {
if (image->format->Rmask == 0x000000ff)
textureFormat = GL_RGB;
else
textureFormat = GL_BGR;
} else {
string msg("IMG error: Unknow pixel format, bpp = ");
msg += bpp;
throw runtime_error(msg.c_str());
}
/* Store widht and height */
originalWidth_ = image->w;
originalHeight_ = image->h;
/* Make OpenGL texture */
glEnable(GL_TEXTURE_2D);
glGenTextures(1, &object_);
glBindTexture(GL_TEXTURE_2D, object_);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, minMagFilter);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, minMagFilter);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapMode);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapMode);
glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);
glTexImage2D(
GL_TEXTURE_2D, // texture type
0, // level
bpp, // internal format
image->w, // width
image->h, // height
0, // border
textureFormat, // format(in this texture?)
GL_UNSIGNED_BYTE, // data type
image->pixels // pointer to data
);
/* Clean these mess up */
glBindTexture(GL_TEXTURE_2D, 0);
glDisable(GL_TEXTURE_2D);
SDL_FreeSurface(image);
}
For more information, you should check out SDL wiki or deep into it's source code to fully understand the architecture of SDL_Surface.

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.

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);

Problem Loading multiple textures using multiple shaders with GLSL

I am trying to use multiple textures in the same scene but no matter what I try the same texture is loaded for each object. So this what I am doing at the moment, I initialise each shader:
rightWall.SendShaders("wall.vert","wall.frag","brick3.bmp", "wallTex", 0);
demoFloor.SendShaders("floor.vert","floor.frag","dirt1.bmp", "floorTex", 1);
The code in SendShaders is:
GLuint vert,frag;
glEnable(GL_DEPTH_TEST);
glEnable(GL_TEXTURE_2D);
char *vs = NULL,*fs = NULL;
vert = glCreateShader(GL_VERTEX_SHADER);
frag = glCreateShader(GL_FRAGMENT_SHADER);
vs = textFileRead(vertFile);
fs = textFileRead(fragFile);
const char * ff = fs;
const char * vv = vs;
glShaderSource(vert, 1, &vv, NULL);
glShaderSource(frag, 1, &ff, NULL);
free(vs); free(fs);
glCompileShader(vert);
glCompileShader(frag);
program = glCreateProgram();
glAttachShader(program, frag);
glAttachShader(program, vert);
glLinkProgram(program);
glUseProgram(program);
LoadGLTexture(textureImage, texture);
And then in the main loop:
rightWall.UseShader("wallTex");
rightWall.Draw();
demoFloor.UseShader("floorTex");
demoFloor.Draw();
The code in UseShader:
void GraphicsObject::UseShader(char textureName []){
glUseProgram(program);
GLint location = glGetUniformLocation(program, textureName);
glUniform1i(location, 0);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture);
}
And finally, the texture load methods:
int GraphicsObject::LoadGLTexture(const char fileName []){
AUX_RGBImageRec *TextureImage[1]; // Create Storage Space For The Texture
memset(TextureImage,0,sizeof(void *)*1); // Set The Pointer To NULL
int arraySize = strlen(fileName);
arraySize += 1;
if (TextureImage[0]=LoadBMP(fileName, arraySize))
{
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, TextureImage[0]->sizeX,
TextureImage[0]->sizeY, 0, GL_RGB,
GL_UNSIGNED_BYTE, TextureImage[0]->data);
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_MIN_FILTER,GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
}
if (TextureImage[0])
{
if (TextureImage[0]->data)
{
free(TextureImage[0]->data);
}
free(TextureImage[0]);
}
return 1;
}
AUX_RGBImageRec* GraphicsObject::LoadBMP(const char fileName[], int arraySize){
FILE *File=NULL;
LPWSTR pwszFileName;
int lenW;
BSTR unicodestr;
lenW = MultiByteToWideChar(CP_ACP, 0, fileName, arraySize, 0,0);
DWORD bottom = GetLastError();
unicodestr = SysAllocStringLen(0, lenW);
MultiByteToWideChar(CP_ACP,0, fileName, arraySize,
unicodestr,lenW);
SysFreeString(unicodestr);
DWORD tit = GetLastError();
if (!fileName)
{
return NULL;
}
File=fopen(fileName,"r");
if (File)
{
fclose(File);
return auxDIBImageLoad((LPCWSTR)unicodestr);
}
return NULL;
}
Which ever shader is initialised last is the texture which is used for both objects. Thank you for your time and I appreciate any comments.
Like you have to call glUseProgram(program) before using the shader for rendering, you also have to bind the right texture directly before rendering.
The code should look like this:
glUseProgram(program1);
glBindTexture(GL_TEXTURE_2D, texture1);
// render calls for object 1
glUseProgram(program2);
glBindTexture(GL_TEXTURE_2D, texture2);
// render calls for object 2
Moreover also Uniforms must be set directly before rendering, and not at shader intialization.
So in your case the part
GLint location = glGetUniformLocation(program, textureName);
glUniform1i(location, 0);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture);
does not belong in the function SendShaders, but in UseShader!
I'm going to point out the obvious just to make sure you can rule it out.
Is your texture image data actually different? Have you checked your texture loading code to make sure you are getting different files for the texture?