OpenGL solid color displayed instead of texture

Question

So, I have looked at all similar questions in this website and others, and I failed to find an answer to why my texture fails to load. I'm sure the texture is read properly, however, it is just not applied correctly. Here's my code:

Getting the texture:

 glGenTextures(NumTextures, textures);

glActiveTexture( GL_TEXTURE0 );

// load and bind tree texture
readPPM6("textures/tree_trunk.pbm", treeTex);

glBindTexture(GL_TEXTURE_2D, textures[0]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 128, 128, 0, GL_RGB,
    GL_UNSIGNED_BYTE, treeTex);

Binding the object:

// VAO[Tree]
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vElements[TreeE]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLushort)*treeIndices.size(), treeIndices.data(), GL_STATIC_DRAW);

glBindVertexArray(vArrays[TreeA]);
glBindBuffer(GL_ARRAY_BUFFER, vBuffers[TreeB]);
glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat)*treeVertices.size() + sizeof(vec2) * 90, NULL, GL_STATIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(GLfloat)*treeVertices.size(), treeVertices.data());
glBufferSubData(GL_ARRAY_BUFFER, sizeof(GLfloat)*treeVertices.size(), sizeof(vec2)*90,
    treeTexCoords);
glUseProgram( texture );
vPosition = glGetAttribLocation( texture, "vPosition" );
glVertexAttribPointer( vPosition, 4, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(vPosition);
vTexCoord = glGetAttribLocation( texture, "vTexCoord" );
glVertexAttribPointer( vTexCoord, 2, GL_FLOAT, GL_FALSE, 0,
    (const void*) ((sizeof(GLfloat) * treeVertices.size())));
glEnableVertexAttribArray( vTexCoord ); 
glUniform1i(glGetUniformLocation(texture, "texture"), 0);
glBindVertexArray(0);

Drawing the tree:

glUseProgram(texture);

proj_loc = glGetUniformLocation(texture, "projection");
model_view_loc = glGetUniformLocation(texture, "modelview");
glUniformMatrix4fv(proj_loc, 1, GL_TRUE, projmat);
glUniformMatrix4fv(model_view_loc, 1, GL_TRUE, modelmat);

glEnable(GL_PRIMITIVE_RESTART);
glPrimitiveRestartIndex(0xFFFF);

glBindVertexArray(vArrays[TreeA]);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vElements[TreeE]);

glEnable(GL_TEXTURE_2D);    

glActiveTexture( GL_TEXTURE0 ); 

glBindTexture(GL_TEXTURE_2D, textures[0]);
glDrawElements(GL_TRIANGLE_STRIP, treeIndices.size(), GL_UNSIGNED_SHORT, NULL);

glDisable(GL_PRIMITIVE_RESTART);
glDisable(GL_TEXTURE_2D);

glUseProgram(0);
glBindVertexArray(0);

The way the tree was created:

getCylinderVertices(treeVertices, 10.0, 3.0, 10);
getCylinderIndices(treeIndices, 10);

getConeVertices(treeVertices, 10.0, 15.0, 6.0, 10);
for (int i = 0; i < 10; i++)
{
    treeIndices.push_back(60+i*3);
    treeIndices.push_back(60+i*3+1);
    treeIndices.push_back(60+i*3+2);
    treeIndices.push_back(0xFFFF);
}

treeTexCoords = new vec2[90];
for (int i = 0; i < 10; i++)
{
    treeTexCoords[i*6] = vec2(0.0, 0.0);
    treeTexCoords[i*6+1] = vec2(0.0, 0.2);
    treeTexCoords[i*6+2] = vec2(0.0, 0.0);
    treeTexCoords[i*6+3] = vec2(1.0, 0.2);
    treeTexCoords[i*6+4] = vec2(1.0, 0.0);
    treeTexCoords[i*6+5] = vec2(0.0, 0.0);
}

for (int i = 0; i < 30; i++)
{
    treeTexCoords[60+i] = vec2(0.0,0.0);
}

Vertex shader:

    #version 330 core

attribute vec4 vPosition;
uniform mat4 projection;
uniform mat4 modelview;

attribute vec4 vertex;
attribute vec3 normal;
attribute vec2 vTexCoord;

out vec2 texCoord;

void main() 
{ 
    texCoord    = vTexCoord;
    gl_Position = projection*modelview*vPosition;
}

Fragment shader:

 #version 330 core

in  vec2 texCoord;

uniform sampler2D texture;

void main() 
{ 
    gl_FragColor = texture2D(texture, texCoord);
}

After fixing a buffer subdata allocation problem, this is how the trees look at the moment: http://i.imgur.com/dMBq9xN.jpg

For reference this is the image I'm using: http://i.imgur.com/QuuQQ5i.jpg

I have solved the final problem, the reader was reading an endline as part of the image, thus everything was shifted to the next color. Thank you all for your help.

Answer 1

I am surprised this code is not causing a crash, sizeof (vec2) * 90 is what you should be using in the second call to glBufferSubData (...) since the number of floating-point components in your texture coordinate array is half the number of components in your vertex position array. You are overrunning both the VBO's storage and your texture coordinate array in client memory when you fill the buffer with data.

sizeof (treeTexCoords) is definitely not what you want, because you have dynamically allocated that array! While you can use sizeof (...) to get the size of a statically sized array if you try to do it with a pointer to memory allocated with new, all you will get is the size of the pointer itself. Thus, sizeof (treeTexCoords) is probably 4 or 8 on your system.

glBindVertexArray (vArrays [TreeA]);
glBindBuffer      (GL_ARRAY_BUFFER, vBuffers [TreeB]);

//
// @CORRECTION #1
//
glBufferData      (GL_ARRAY_BUFFER, sizeof (GLfloat) * treeVertices.size () + 
                                    sizeof (vec2)    * 90,
                                        NULL, GL_STATIC_DRAW);
glBufferSubData   (GL_ARRAY_BUFFER, 0,
                                    sizeof (GLfloat) * treeVertices.size (),
                                        treeVertices.data ());
//
// @CORRECTION #2
//
glBufferSubData   (GL_ARRAY_BUFFER, sizeof (GLfloat) * treeVertices.size (), 
                                    sizeof (vec2)    * 90,
                                        treeTexCoords);

Correction #1 allocates the appropriate amount of storage (instead of enough storage for all of your vertices + 1 pointer).

Correction #2 reads only up to the end of treeTexCoords instead of overrunning it.

There may be additional issues depending on how treeVertices is declared - can you edit your question to show the declaration of treeVertices? I am assuming it is something like std::vector <GLfloat>.