Hello everybody,

I have an annoying problem while trying to make my cube have a texture,

my vertex shader just gives the texture coords to the fragment shader

Here is the code

Texture Loading Code:

int width, height;
 
FIBITMAP* bitmap = FreeImage_Load(FreeImage_GetFileType("assets/textures/basic_tile.png", 0), "assets/textures/basic_tile.png");
FIBITMAP *img = FreeImage_ConvertTo32Bits(bitmap);
width = FreeImage_GetWidth(img);
height = FreeImage_GetHeight(img);
 
glGenTextures(1, &tex);
glBindTexture(GL_TEXTURE_2D, tex);
 
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 
width, height, 0, GL_RGBA,
GL_UNSIGNED_BYTE, (void*)FreeImage_GetBits(img));
 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 
glGenerateMipmap(GL_TEXTURE_2D);
 
FreeImage_Unload(bitmap);
FreeImage_Unload(img);
 

 
in vec2 TexCoord;
 
out vec4 fragColor;
 
uniform sampler2D tex;
 
void main()
{
fragColor = texture(tex, TexCoord);
}
 

well, I'm following some tutorial like open.gl and I just searched how to use freeimage, but I don't really know about how the textures is passed through.

like you probably have noticed from the line above, I'm relatively new to opengl.

The texture is not showing.

well, I haven't set up any uniform for the texture unit, so that is my problem.

can you tell me how.

here is my setup code:

aspect = (GLfloat)screen_width / (GLfloat)screen_height;
 
glClearColor(0.1f, 0.1f, 0.2f, 1.0f);
 
glEnable(GL_DEPTH_TEST);
glEnable(GL_TEXTURE_2D);
 
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
 
float vertices[] = {
//X      Y      Z     R     G     B    UV X  UV Y
-0.5f,  0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f,
0.5f,  0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f,
0.5f, -0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f,
 
-0.5f,  0.5f,  0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f,
0.5f,  0.5f,  0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f,
0.5f, -0.5f,  0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,
-0.5f, -0.5f,  0.5f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f
};
 
glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
 
GLuint elements[] = {
3, 2, 1,
1, 0, 3,
 
7, 6, 5,
5, 4, 7,
 
4, 0, 3,
3, 7, 4,
 
5, 1, 2,
2, 6, 5,
 
3, 2, 6,
6, 7, 3,
 
0, 1, 5, 
5, 4, 0
};
 
glGenBuffers(1, &ebo);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(elements), elements, GL_STATIC_DRAW);
 
vertexShader = new Shader("defaultVert.glsl", GL_VERTEX_SHADER);
fragmentShader = new Shader("defaultFrag.glsl", GL_FRAGMENT_SHADER);
 
shaderProg = new ShaderProgram();
shaderProg->attachShader(vertexShader);
shaderProg->attachShader(fragmentShader);
 
shaderProg->bindFragDataLocation(0, "fragColor");
 
shaderProg->link();
shaderProg->Use();
 
positionLoc = shaderProg->getAttribLoc("vPosition");
glEnableVertexAttribArray(positionLoc);
glVertexAttribPointer(positionLoc, 3, GL_FLOAT, GL_FALSE, 8*sizeof(float), 0);
 
colorLoc = shaderProg->getAttribLoc("color");
glEnableVertexAttribArray(colorLoc);
glVertexAttribPointer(colorLoc, 3, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void*)(3*sizeof(float)));
 
texLoc = shaderProg->getAttribLoc("texCoord");
glEnableVertexAttribArray(texLoc);
glVertexAttribPointer(texLoc, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
 
int width, height;
 
FIBITMAP* bitmap = FreeImage_Load(FreeImage_GetFileType("assets/textures/basic_tile.png", 0), "assets/textures/basic_tile.png");
FIBITMAP *img = FreeImage_ConvertTo32Bits(bitmap);
width = FreeImage_GetWidth(img);
height = FreeImage_GetHeight(img);
 
glGenTextures(1, &tex);
glBindTexture(GL_TEXTURE_2D, tex);
 
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 
width, height, 0, GL_RGBA,
GL_UNSIGNED_BYTE, (void*)FreeImage_GetBits(img));
 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 
glGenerateMipmap(GL_TEXTURE_2D);
 
FreeImage_Unload(bitmap);
FreeImage_Unload(img);

well, I've added this to my code

texLoc = shaderProg->GetUniformLoc("tex");
glUniform1i(texLoc, 0);

but it still doesn't show my texture

well, here is my code in a zip, the camera class and inputmanager isn't really used

link: https://www.dropbox.com/s/d1yf5hwtjbj6v3z/TJGS%20Engine.zip