GLSL Variables Not Getting VBO Data - c++

Question

There must be something wrong with how I'm implementing my VAOs and VBOs because my shader isn't getting any of the buffer data I'm allocating to it. It could be something to do with the location of the variables. I tried printing out the location value from glGetUniformLocation (my loc variable), and it printed out 4294967295 for every location value. I would think there's a different location for each of them. I also tried using the location (location = ...) values from the vertex shader and that didn't work either. Any extra insight would be greatly appreciated.
Here is my rendering code:
// load shaders and textures to the current context
glUseProgram(cloudShader);
glActiveTexture(cloudTexture);
glBindTexture(GL_TEXTURE_2D, cloudTexture);
glEnable(GL_POINTS);
glDisable(GL_DEPTH_TEST);
glPointSize(10.0f);
// initial velocity and start time buffer
GLuint vbo[3];
// texture position buffer
GLuint textPosBuf;
glGenBuffers(3, vbo);
//glGenBuffers(1, &textPosBuf);
// gen vao object
GLuint vao[3];
glGenVertexArrays(3, vao);
// define uniforms
glUniform4f(glGetUniformLocation(cloudShader, "color1"), color1.r, color1.g, color1.b, color1.a);
glUniform4f(glGetUniformLocation(cloudShader, "color2"), color2.r, color2.g, color2.b, color2.a);
glUniform3f(glGetUniformLocation(cloudShader, "Accel"), accel.x, accel.y, accel.z);
glUniform1f(glGetUniformLocation(cloudShader, "color1Wght"), color1Wght);
glUniform1f(glGetUniformLocation(cloudShader, "Time"), time);
glUniformMatrix4fv(glGetUniformLocation(cloudShader, "MVP"), 1, GL_FALSE, value_ptr(mat4(GL_PROJECTION_MATRIX) * mat4(GL_MODELVIEW_MATRIX)));
glUniform1i(glGetUniformLocation(cloudShader, "ParticleTex"), cloudTexture);
GLfloat *data = new GLfloat[nParticles * 3];
// I then set data ...
// bind vertex buffer data
// initial velocity data
glBindVertexArray(vao[0]);
glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);
glBufferData(GL_ARRAY_BUFFER, nParticles * 3 * sizeof(GLfloat), reinterpret_cast<void*>(data), GL_DYNAMIC_DRAW);
// VertexInitVel attrib array pointer setup
GLuint loc = glGetUniformLocation(cloudShader, "VertexInitVel");
glVertexAttribPointer(loc, 3, GL_FLOAT, GL_FALSE, NULL, NULL);
glEnableVertexAttribArray(loc);
// start time data
data = new GLfloat[nParticles];
// I then set the data...
// load start time buffer data
glBufferData(GL_ARRAY_BUFFER, nParticles * sizeof(GLfloat),
reinterpret_cast<void*>(data), GL_DYNAMIC_DRAW);
// InitStartTime attrib array pointer setup
loc = glGetUniformLocation(cloudShader, "StartTime");
glVertexAttribPointer(loc, 1, GL_FLOAT, GL_FALSE, NULL, NULL);
glEnableVertexAttribArray(loc);
// buffer texture position data
data = new GLfloat[nParticles * 2];
// I then set the data...
glBindVertexArray(vao[1]);
glBindBuffer(GL_ARRAY_BUFFER, vbo[1]);
glBufferSubData(GL_ARRAY_BUFFER, nParticles * sizeof(GLfloat),
nParticles * 2 * sizeof(GLfloat), reinterpret_cast<void*>(data));
loc = glGetUniformLocation(cloudShader, "texCoordIn");
cout << loc << endl;
glVertexAttribPointer(loc, 2, GL_FLOAT, GL_FALSE, NULL,
reinterpret_cast<void*>(nParticles * sizeof(GLfloat)));
glEnableVertexAttribArray(loc);
// buffer particle position data
data = new GLfloat[nParticles * 3];
// data gets set...
glBindVertexArray(vao[2]);
glBindBuffer(GL_ARRAY_BUFFER, vbo[2]);
glBufferData(GL_ARRAY_BUFFER, nParticles * 3 * sizeof(GLfloat), reinterpret_cast<void*>(data), GL_DYNAMIC_DRAW);
loc = glGetUniformLocation(cloudShader, "VertexStartPos");
glEnableVertexAttribArray(loc);
glVertexAttribPointer(loc, 3, GL_FLOAT, GL_FALSE, NULL, NULL);
glDrawArrays(GL_POINTS, 0, nParticles);
// cleanup
....
Here is my vertex shader:
#version 450
// information to pass to the fragment shader
out vec2 texCoord; // texture coordinate to pass to fragment shader
out vec4 color1Pass;
out vec4 color2Pass;
out float color1WghtPass;
// Initial velocity and start time
layout (location = 0) in vec3 VertexInitVel;
layout (location = 1) in float StartTime;
layout (location = 2) in vec3 VertexStartPos; // where particle "respawns"
layout (location = 3) in vec2 texCoordIn;
// various values
uniform vec4 color1;
uniform vec4 color2;
uniform float color1Wght; // how strongly color1 is weighted
uniform float Time; // Animation time
uniform mat4 MVP;
uniform vec3 Accel; // Particle acceleration
out float Transp; // Transparency of the particle
const float ParticleLifetime = 10.0f; // Max particle lifetime
void main()
{
// Assume the initial position is as defined by Vertex Start Pos.
// vec3 pos = VertexStartPos;
vec3 pos = vec3(0.0);
Transp = 0.0;
// Particle doesn't exist until the start time
if( Time > StartTime ) {
float t = Time - StartTime;
// particle is born
if( t < ParticleLifetime ) {
pos = VertexInitVel * t + Accel * t * t;
Transp = 1.0 - t / ParticleLifetime;
}
}
color1Pass = color1;
color2Pass = color2;
color1WghtPass = color1Wght;
gl_Position = MVP * vec4(pos, 1.0);
}