Trouble displaying texture

OpenGL OpenGL: Basic Coding
1

Hello everyone, I am trying to load texture using the SOIL library and display it on screen. I’m trying to make a simple 2D game but for some reason I’m unable to load the background. Could anyone please point out where I’m going wrong?

Here’s my load texture function:


void LoadTexture()
{
	int iWidth, iHeight;
	unsigned char* image = SOIL_load_image("background0.png", &iWidth, &iHeight, 0, SOIL_LOAD_RGB);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, iWidth, iHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
	glGenerateMipmap(GL_TEXTURE_2D);
	SOIL_free_image_data(image);
	glBindTexture(GL_TEXTURE_2D, 0);
}

Here’s where I’m doing several startups.

void Init()
{
//... (init glew etc...)
GLfloat Texture[] =
	{
		0.0f, 0.0f,  // Top Left
		1.0f, 0.0f,  // Top Right
		1.0f, 1.0f,  // Bottom Right
		0.0f, 1.0f   // Bottom Left
	};

        // Create vertex and fragment shader
	program = myShader.CreateProgram("VertexShader.vs", "FragShader.fs");

	// .... (generate buffers for vao, vbo etc...)

	glGenBuffers(1, &g_texture);
	glBindTexture(GL_TEXTURE_2D, g_texture);
	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, (GLvoid*)0);

	LoadTexture();

	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_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	glEnableVertexAttribArray(0);
	glEnableVertexAttribArray(1);
	glEnableVertexAttribArray(2);
}

Here’s my render function:


void Render()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glUseProgram(program);
	LoadTexture();
	glBindVertexArray(vao);
	glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_BYTE, 0); 
	glBindVertexArray(0);

	glutSwapBuffers();
}

And lastly, here are my shaders:

Fragment Shader:

#version 430 core

in vec4 outputColors;
in vec2 TexCoord;

out vec4 VertexColors;

uniform sampler2D aTexture;

void main()
{
	VertexColors = texture(aTexture, TexCoord) * outputColors; // <-- Displays black screen :( 
	//VertexColors = outputColors; <-- works (displays a colored quad)
}

Vertex Shader:

#version 430 core

in layout (location = 0) vec3 VertexPos;
in layout (location = 1) vec4 VertexColors;
in layout (location = 2) vec2 TextureCoord;

out vec4 outputColors;
out vec2 TexCoord;

void main()
{
	gl_Position = vec4(VertexPos, 1.0f);
	outputColors = VertexColors;
	TexCoord = TextureCoord;
}

The output of this is a black window.

All help is appreciated, thank you so much for reading my query.

2

What have you tried? Have you verified that the image loaded contains reasonable data? Have you checked for GL errors? Have you tried using your texture coordinates as the red/green color output values? Do they look reasonable? etc.

3 
glGenBuffers(1, &g_texture);
glBindTexture(GL_TEXTURE_2D, g_texture);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, (GLvoid*)0);

This, basically.

You’re generating a buffer, then you’re binding the buffer name as a texture, then you’re setting up your vertex attrib pointer.

I suspect that your intention is that this glBindTexture call really should be a glBindBuffer call, and then you also need to use glGenTextures and glBindTexture before your glTexImage call.