Hello,
I’m trying to draw things using by element array buffer in the 3D space.
However I can’t draw anything with element array buffer but with vertex array buffer.
Can you please advice me how to fix the issue?
Below is my codes
[Vertex Shader]
#version 450 core
layout (location = 0) in vec3 aPos;
out vec4 aColor;
uniform mat4 projection;
uniform mat4 view;
uniform mat4 model;
uniform vec4 color;
uniform float size;
void main() {
aColor = color;
gl_Position = projection * view * model * vec4(aPos, 1.0);
gl_PointSize = size;
}
[Fragment Shader]
#version 450 core
in vec4 aColor;
out vec4 FragColor;
void main() {
FragColor = aColor;
}
[Vertices and Indices]
float vertice[] = {
-0.2, 0.2, -0.2,
-0.2, 0.2, 0.2,
0.2, 0.2, -0.2,
0.2, 0.2, 0.2,
0.2, -0.2, -0.2,
0.2, -0.2, 0.2,
-0.2, -0.2, -0.2,
-0.2, -0.2, 0.2
};
float surfaceIncides[] = {
0, 3, 2,
3, 0, 1,
4, 7, 6,
7, 4, 5,
1, 5, 3,
5, 1, 7,
2, 6, 0,
6, 2, 4,
3, 4, 2,
4, 3, 5,
0, 7, 1,
7, 0, 6
};
unsigned int VBO, VAO;
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertice), vertice, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*)0);
glEnableVertexAttribArray(0);
GLuint surfaceEAB;
glGenBuffers(1, &surfaceEAB);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, surfaceEAB);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(surfaceIncides), surfaceIncides, GL_STATIC_DRAW);
[Drawing codes]
// Draw Cube
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, surfaceEAB);
glDrawElements(GL_TRIANGLES, 36, GL_UNSIGNED_INT, 0);
glBindVertexArray(0);
// Draw points
glPolygonMode(GL_FRONT_AND_BACK, GL_POINT);
modeling.setFloat("size", 10.0);
glBindVertexArray(VAO);
glDrawArrays(GL_POINTS, 0, 8);
glBindVertexArray(0);
[Result]
