OpenGL not rendering anything at all - c++

Question

My program doesn't display anything on the screen. I've tried several things but nothing worked.
Here's my source, vertex and fragment shader:
Renderer.cpp:
#include "Renderer.h"
Renderer::Renderer( Camera& camera, float w, float h )
:
cam( camera ),
winW( w ),
winH( h )
{}
Renderer::~Renderer()
{
glDeleteBuffers( 1, &quad );
glDeleteBuffers( 1, &color );
glDeleteBuffers( 1, &UV );
glDeleteVertexArrays( 1, &vao );
}
void Renderer::load()
{
projectionMatrix = glm::mat4( 1.0f );
projectionMatrix = glm::perspective<float>( 45.0f, (float) winW / (float) winH, 0.01f, 100.0f );
shader.loadAndCompile( "Res/Shaders/std.vs", "Res/Shaders/std.fs" );
texture.loadTexture( "Res/Tex/sheet.png" );
texture.bind();
glGenVertexArrays( 1, &vao );
glBindVertexArray( vao );
Vertex quadArray[] = {
{ -0.5, -0.5, 0.0 },
{ -0.5, 0.5, 0.0 },
{ 0.5, -0.5, 0.0 },
{ 0.5, -0.5, 0.0 },
{ 0.5, 0.5, 0.0 },
{ -0.5, 0.5, 0.0 }
};
glUseProgram( shader.getProgram() );
MVPLocation = glGetUniformLocation( shader.getProgram(), "MVP" );
glGenBuffers( 1, &quad );
glBindBuffer( GL_ARRAY_BUFFER, quad );
glBufferData( GL_ARRAY_BUFFER, sizeof( quadArray ), quadArray, GL_STATIC_DRAW );
glGenBuffers( 1, &color );
glBindBuffer( GL_ARRAY_BUFFER, color );
glBufferData( GL_ARRAY_BUFFER, 48, NULL, GL_STREAM_DRAW );
glGenBuffers( 1, &UV );
glBindBuffer( GL_ARRAY_BUFFER, UV );
glBufferData( GL_ARRAY_BUFFER, 48, NULL, GL_STREAM_DRAW );
}
void Renderer::translate( glm::vec3 pos )
{
this->transMatrix = glm::translate( glm::mat4( 1.0f ), pos );
}
void Renderer::translate( float x, float y, float z )
{
translate( glm::vec3( x, y, z ) );
}
void Renderer::rotate( float angle, glm::vec3 axis )
{
this->rotationMatrix = glm::rotate( glm::mat4( 1.0f ), angle, axis );
}
void Renderer::scale( glm::vec3 scale )
{
this->scaleMatrix = glm::scale( glm::mat4( 1.0f ), scale );
}
void Renderer::scale( float x, float y, float z )
{
scale( glm::vec3( x, y, z ) );
}
void Renderer::drawSpriteBillboarded( glm::vec3 pos, glm::vec3 lookAtPos, int w, int h, int uP, int vP, glm::vec4 col )
{
int texW = texture.getWidth(), texH = texture.getHeight();
float u = (float) uP / (float) texW, v = (float) vP / (float) texH, uEnd = (float) ( uP + w ) / (float) texW, vEnd = (float) ( vP + h ) / (float) texH;
Color colArray[] = {
{ col.r, col.g, col.b, col.a },
{ col.r, col.g, col.b, col.a },
{ col.r, col.g, col.b, col.a },
{ col.r, col.g, col.b, col.a },
{ col.r, col.g, col.b, col.a },
{ col.r, col.g, col.b, col.a }
};
Vertex uvArray[] = {
{ u, v },
{ u, vEnd },
{ uEnd, v },
{ uEnd, v },
{ uEnd, vEnd },
{ u, vEnd }
};
translate( pos );
glm::vec2 dist = glm::vec2( lookAtPos.x, lookAtPos.z ) - glm::vec2( pos.x, pos.z );
rotate( atan2f( dist.y, dist.x ), glm::vec3( 0, 1, 0 ) );
scale( w / 16 * 1.0, h / 16 * 1.0, 1.0 );
modelMatrix = transMatrix * rotationMatrix * scaleMatrix;
camTransMatrix = glm::translate( glm::mat4( 1.0f ), cam.getPos() );
camRotationMatrix = glm::rotate( camRotationMatrix, cam.getRotX(), glm::vec3( 1, 0, 0 ) );
camRotationMatrix = glm::rotate( camRotationMatrix, cam.getRotY(), glm::vec3( 0, 1, 0 ) );
camRotationMatrix = glm::rotate( camRotationMatrix, cam.getRotZ(), glm::vec3( 0, 0, 1 ) );
viewMatrix = camTransMatrix * camRotationMatrix;
modelViewProjectionMatrix = projectionMatrix * viewMatrix * modelMatrix;
glUniformMatrix4fv( MVPLocation, 1, GL_FALSE, &modelViewProjectionMatrix[ 0 ][ 0 ] );
glBindBuffer( GL_ARRAY_BUFFER, quad );
glEnableVertexAttribArray( 0 );
glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, 0, (void*) 0 );
glBindBuffer( GL_ARRAY_BUFFER, color );
glBufferData( GL_ARRAY_BUFFER, sizeof( colArray ), colArray, GL_STREAM_DRAW );
glEnableVertexAttribArray( 1 );
glVertexAttribPointer( 1, 4, GL_UNSIGNED_BYTE, GL_TRUE, 0, (void*)0 );
glBindBuffer( GL_ARRAY_BUFFER, UV );
glBufferData( GL_ARRAY_BUFFER, sizeof( uvArray ), uvArray, GL_STREAM_DRAW );
glEnableVertexAttribArray( 2 );
glVertexAttribPointer( 2, 2, GL_FLOAT, GL_FALSE, 0, (void*)0 );
glDrawElements( GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, 0 );
}
void Renderer::drawSprite( glm::vec3 pos, int w, int h, int uP, int vP, glm::vec4 col )
{}
vertex shader
#version 330 core
layout(location = 0) in vec3 vertPosition;
layout(location = 1) in vec4 color;
layout(location = 2) in vec2 in_UV;
uniform mat4 MVP;
out vec4 col;
out vec2 uv;
void main(void)
{
gl_Position = MVP * vec4(vertPosition, 1.0);
col = color;
uv = in_UV;
}
fragment shader
#version 330 core
in vec4 col;
in vec2 uv;
out vec4 color;
uniform sampler2D tex;
void main(void)
{
vec4 Color = texture2D( tex, uv ) * col;
color = Color;
}
I call the drawSpriteBillboarded function from my Game class like so:
drawSpriteBillboarded( glm::vec3( 0, 0, -5 ), cam.getPos(), 16, 16, 0, 0, glm::vec3( 255, 255, 255, 255 ) );
The camera's position is at 0, 0, 0
I've tried changing the vertex shader to not multiply by the MVP matrix and also tried changing the fragment shader to this:
#version 330 core
in vec4 col;
in vec2 uv;
out vec4 color;
void main(void)
{
color = vec4(1.0, 1.0, 1.0, 1.0);
}
But it doesn't show anything either.
I've also tried changing GL_TRIANGLES to GL_POINTS, but nothing.
EDIT
I also added the loadAndCompile() function:
void Shader::loadAndCompile( const char* vertPath, const char* fragPath )
{
std::string vsCode = "";
std::ifstream vsStream( vertPath, std::ios::in );
fprintf( stdout, "loading vertex shader %s\n", vertPath );
if( vsStream.is_open() )
{
std::string line;
while( std::getline( vsStream, line ) )
vsCode += line + '\n';
vsStream.close();
}
else
{
fprintf( stderr, "Error: could not find vertex shader %s\n", vertPath );
return;
}
std::string fsCode = "";
std::ifstream fsStream( fragPath, std::ios::in );
fprintf( stdout, "loading fragment shader %s\n", fragPath );
if( fsStream.is_open() )
{
std::string line;
while( std::getline( fsStream, line ) )
fsCode += line + '\n';
fsStream.close();
}
else
{
fprintf( stderr, "Error: could not find fragment shader %s\n", fragPath );
return;
}
fprintf( stdout, "Compiling vertexShader %s\n", vertPath );
const char* vertCode = vsCode.c_str();
GLuint vertShader = glCreateShader( GL_VERTEX_SHADER );
glShaderSource( vertShader, 1, &vertCode, NULL );
glCompileShader( vertShader );
GLint result = GL_FALSE;
int infoLogLength;
glGetShaderiv( vertShader, GL_COMPILE_STATUS, &result );
glGetShaderiv( vertShader, GL_INFO_LOG_LENGTH, &infoLogLength );
if( infoLogLength > 0 )
{
std::vector< char > errorMsg( infoLogLength );
glGetShaderInfoLog( vertShader, infoLogLength, NULL, &errorMsg[ 0 ] );
fprintf( stderr, "%s\n", &errorMsg[ 0 ] );
}
fprintf( stdout, "Compiling fragmentShader %s\n", fragPath );
const char* fragCode = fsCode.c_str();
GLuint fragShader = glCreateShader( GL_FRAGMENT_SHADER );
glShaderSource( fragShader, 1, &fragCode, NULL );
glCompileShader( fragShader );
glGetShaderiv( fragShader, GL_COMPILE_STATUS, &result );
glGetShaderiv( fragShader, GL_INFO_LOG_LENGTH, &infoLogLength );
if( infoLogLength > 0 )
{
std::vector< char > errorMsg( infoLogLength );
glGetShaderInfoLog( fragShader, infoLogLength, NULL, &errorMsg[ 0 ] );
fprintf( stderr, "%s\n", &errorMsg[ 0 ] );
}
fprintf( stdout, "Linking program...\n" );
GLuint tmpProgID = glCreateProgram();
glAttachShader( tmpProgID, vertShader );
glAttachShader( tmpProgID, fragShader );
glLinkProgram( tmpProgID );
glGetProgramiv( tmpProgID, GL_LINK_STATUS, &result );
glGetProgramiv( tmpProgID, GL_INFO_LOG_LENGTH, &infoLogLength );
if( infoLogLength > 0 )
{
std::vector< char > errorMsg( infoLogLength );
glGetProgramInfoLog( tmpProgID, infoLogLength, NULL, &errorMsg[ 0 ] );
fprintf( stderr, "%s\n", &errorMsg[ 0 ] );
}
glDeleteShader( vertShader );
glDeleteShader( fragShader );
this->programID = tmpProgID;
}
So I'm basically asking you to check my code to see if I made a (silly) mistake.

Answer 1

Solved! - The winW and winH variables were not initialized when the constructor gets called.
I also had to change glDrawElements(...) to glDrawArrays(...)