Extended Rotating Cube Example with Texturing [closed] - c

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I am currently working on an extension for a working rotation cube example.
But since there were much changes, because index_buffers are not a good idea for texture, I
have now a bug. I can't figure out why my cube consists only of some triangles now.
So I hope that someone else can find the problem.
For better understaning I put the whole code on this page.
https://www.dropbox.com/s/0mj5wb56rfzvpsx/Rotating_Cube.zip
GLfloat vertex_buffer_data[] = { /* 8 cube vertices */
-1.0, -1.0, 1.0,
1.0, -1.0, 1.0,
1.0, 1.0, 1.0,
-1.0, 1.0, 1.0,
-1.0, -1.0, -1.0,
1.0, -1.0, -1.0,
1.0, 1.0, -1.0,
-1.0, 1.0, -1.0,
};
GLushort index_buffer_data[] = { // Indices of 6*2 triangles
0, 1, 2,
2, 3, 0,
1, 5, 6,
6, 2, 1,
7, 6, 5,
5, 4, 7,
4, 0, 3,
3, 7, 4,
4, 5, 1,
1, 0, 4,
3, 2, 6,
6, 7, 3,
};
GLfloat UV[] = {
0.0, 0.0,
1.0, 1.0,
0.0, 1.0,
0.0, 0.0,
1.0, 0.0,
1.0, 1.0,
0.0, 0.0,
1.0, 1.0,
0.0, 1.0,
0.0, 0.0,
1.0, 0.0,
1.0, 1.0,
0.0, 0.0,
1.0, 1.0,
0.0, 1.0,
0.0, 0.0,
1.0, 0.0,
1.0, 1.0,
0.0, 0.0,
1.0, 1.0,
0.0, 1.0,
0.0, 0.0,
1.0, 0.0,
1.0, 1.0,
0.0, 0.0,
1.0, 1.0,
0.0, 1.0,
0.0, 0.0,
1.0, 0.0,
1.0, 1.0,
0.0, 0.0,
1.0, 1.0,
0.0, 1.0,
0.0, 0.0,
1.0, 0.0,
1.0, 1.0
};
typedef struct {
GLfloat Position[3];
GLfloat UV[2];
} VertexData;
VertexData Vertices[index_size];
/*----------------------------------------------------------------*/
/******************************************************************
*
* Display
*
* This function is called when the content of the window needs to be
* drawn/redrawn. It has been specified through 'glutDisplayFunc()';
* Enable vertex attributes, create binding between C program and
* attribute name in shader
*
*******************************************************************/
void Display()
{
/* Clear window; color specified in 'Initialize()' */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnableVertexAttribArray(vPosition);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glVertexAttribPointer(vPosition, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(vUV);
glBindBuffer(GL_ARRAY_BUFFER, TextureID);
glVertexAttribPointer(vUV, 2, GL_FLOAT, GL_FALSE, 0, 0);
/*glEnableVertexAttribArray(vColor);
glBindBuffer(GL_ARRAY_BUFFER, CBO);
glVertexAttribPointer(vColor, 3, GL_FLOAT,GL_FALSE, 0, 0);
*/
//glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO);
//GLint size;
//glGetBufferParameteriv(GL_ELEMENT_ARRAY_BUFFER, GL_BUFFER_SIZE, &size);
/* Activate first (and only) texture unit */
glActiveTexture(GL_TEXTURE0);
/* Bind current texture */
glBindTexture(GL_TEXTURE_2D, TextureID);
/* Get texture uniform handle from fragment shader */
TextureUniform = glGetUniformLocation(ShaderProgram, "myTextureSampler");
/* Set location of uniform sampler variable */
glUniform1i(TextureUniform, 0);
/* Enable position and UV attribute */
glEnableVertexAttribArray(vPosition);
glEnableVertexAttribArray(vUV);
glVertexAttribPointer(vPosition, 3, GL_FLOAT, GL_FALSE, sizeof(vertex_buffer_data), 0);
glVertexAttribPointer(vUV, 2, GL_FLOAT, GL_FALSE, sizeof(VertexData), (const GLvoid*) sizeof(Vertices[0].Position));
/* Associate program with shader matrices */
GLint projectionUniform = glGetUniformLocation(ShaderProgram, "ProjectionMatrix");
if (projectionUniform == -1)
{
fprintf(stderr, "Could not bind uniform ProjectionMatrix\n");
exit(-1);
}
glUniformMatrix4fv(projectionUniform, 1, GL_TRUE, ProjectionMatrix);
GLint ViewUniform = glGetUniformLocation(ShaderProgram, "ViewMatrix");
if (ViewUniform == -1)
{
fprintf(stderr, "Could not bind uniform ViewMatrix\n");
exit(-1);
}
glUniformMatrix4fv(ViewUniform, 1, GL_TRUE, ViewMatrix);
GLint RotationUniform = glGetUniformLocation(ShaderProgram, "ModelMatrix");
if (RotationUniform == -1)
{
fprintf(stderr, "Could not bind uniform ModelMatrix\n");
exit(-1);
}
glUniformMatrix4fv(RotationUniform, 1, GL_TRUE, ModelMatrix);
glDrawArrays(GL_TRIANGLES, 0, numVertices);
/* Disable attributes */
glDisableVertexAttribArray(vPosition);
glDisableVertexAttribArray(vUV);
/* Swap between front and back buffer */
glutSwapBuffers();
}
void SetupDataBuffers()
{
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW);
}
void getNewVertices() {
int i;
for(i=0; i < index_size; i++){
Vertices[i].Position[0] = vertex_buffer_data[3*index_buffer_data[i]+0];
Vertices[i].Position[1] = vertex_buffer_data[3*index_buffer_data[i]+1];
Vertices[i].Position[2] = vertex_buffer_data[3*index_buffer_data[i]+2];
Vertices[i].UV[0] = UV[2*i];
Vertices[i].UV[1] = UV[2*i+1];
}
}

Answer 1

First of all, your vertex pointers are wrong.
You are not using (a VBO named) TextureID anywhere, so remove all of this code:
glEnableVertexAttribArray(vPosition);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glVertexAttribPointer(vPosition, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(vUV);
glBindBuffer(GL_ARRAY_BUFFER, TextureID);
glVertexAttribPointer(vUV, 2, GL_FLOAT, GL_FALSE, 0, 0);
Replace it with:
glBindBuffer (GL_ARRAY_BUFFER, VBO);
glEnableVertexAttribArray (vPosition);
glEnableVertexAttribArray (vUV);
Finally, since you pack position and uv into an array of structs, this is what you want:
glVertexAttribPointer (vPosition, 3, GL_FLOAT, GL_FALSE, sizeof(VertexData), 0);
glVertexAttribPointer (vUV, 2, GL_FLOAT, GL_FALSE, sizeof(VertexData), (const GLubyte*)0 + offsetof(struct VertexData,UV));
That will fix everything I immediately see wrong with your code, there may still be other issues that I missed.