Advertisements Hi, I’m trying to write a program with OpenGL using c++, glad and glfw, but I’ve encountered a problem I cannot wrap my head around. main.cpp #include <glad/glad.h> #include <GLFW/glfw3.h> #include <iostream> #define SCR_WIDTH 1280 #define SCR_Height 720 int main() { GLFWwindow* window = init(); unsigned int VAO, VBO, EBO; glGenVertexArrays(1, &VAO); glGenBuffers(1, &VBO);… Read More OpenGL modifies variable without being explicitly told to

Advertisements I’m trying to do some 3D graphics using OpenGL, with cglm for math. I was following a guide that lead me to multiplying my vertex position by 3 matrices: model, view and projection. Since the tutorial wasn’t in the same language as me, I couldn’t follow it one-by-one, so I did the projection matrix… Read More Vertex shader: Multiplying by projection matrix give me blank screen

Advertisements I am working on an OpenGL project which makes use of GLFW and OpenGL, however I cannot manage to successfully include GLFW in my project. I am on Linux Mint, and am using C code compiled via terminal with clang version 10.0.0-4ubuntu1. IDE is Visual Studio Code. Code: #include "gui/window.h" void key_callback(GLFWwindow* window, int… Read More How to properly set up GLFW for a c project?

Advertisements I create a GL_ARRAY_BUFFER and GL_ELEMENT_ARRAY_BUFFER and allocated space in both with glBufferData(null), then I glBufferSubData() some data into certain sections of the buffers, leaving some sections (not just at the end) null. Then I draw the entire GL_ELEMENT_ARRAY_BUFFER with glDrawElements(). Is leaving certain sections null like that allowed or does it have downsides?… Read More Does drawing a partially empty GL_ELEMENT_ARRAY_BUFFER work?

Advertisements This is the draw call for glDrawElements glDrawElements(GL_TRIANGLES, indicesTaperRectangle.size(), GL_UNSIGNED_INT, 0); can i add the start offset value like it should start from the 3rd index value ? >Solution : When a named buffer object is bound to the GL_ELEMENT_ARRAY_BUFFER target, the last argument of glDrawElements is treated as a byte offset as a… Read More Can we add a start offset value to glDrawElements

Advertisements I’m trying to draw a textured cube in OpengL. At first, I initialize VBO and VAO in the class constructor as follows. Block::Block(…) { glGenBuffers(1, &VBO); glGenVertexArrays(1, &VAO); //glBindBuffer(GL_ARRAY_BUFFER, VBO); glBindVertexArray(VAO); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)0); glEnableVertexAttribArray(0); glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)(3 * sizeof(float))); glEnableVertexAttribArray(1); glVertexAttribPointer(2,… Read More Confused about having to bind VBO before editing VAO

Advertisements so I got an exception thrown when I used the function glGenBuffer. can anyone help me to fix it? P.S. I am using glad instead of glew. #include <glad/glad.h> #include <GLFW/glfw3.h> #include <iostream> using namespace std; unsigned int createShader(unsigned int shadertype, const char* shaderSource) { unsigned int shader; shader = glCreateShader(shadertype); glShaderSource(shader, 1, &shaderSource,… Read More Exception thrown at 0x00000000 in CobwebDiagram.exe: 0xC0000005: Access violation executing location 0x00000000

Advertisements OpenGL draws only the background, the yellow point does not appear. I want to draw it with glBegin and glEnd. The coordinates are variables, because I want to move that point later. Most of the code is just glfw initialization the function that worries me is the draw_player function since there the drawcall is… Read More OpenGL doesn't draw a point

Advertisements Following this resource for cubemap, it uses a trick for always having the cubemap at z=1 with gl_Position = pos.xyww. With perspective division, each pixel will have its depth set to w / w = 1. I have some questions regarding this. void main() { vec4 pos = projection * view * vec4(aPos, 1.0);… Read More OpenGL : Cubemap hack to always have z=1

Advertisements Sometimes we need to initialize a texture without data. So I want to write an utility function, something like that: GLuint create_texture(GLenum internal_format, int width, int height) { GLuint id; glGenTextures(1, &id); glBindTexture(GL_TEXTURE_2D, id); glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, GL_RGB, GL_FLOAT, NULL); return id; } I want to be able to initialize with… Read More OpenGL : error with invalid format but NULL data