So i am trying to make a game where I want to update my player and enemy. enemy and player are squares. I have a square class with VAO, VBO, EBO and vertices where I load my square.
void Square::loadSquare()
{
unsigned int indices[] = {
0, 1, 3, // first triangle
1, 2, 3 // second triangle
};
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glGenBuffers(1, &EBO);
// bind vertex array object
glBindVertexArray(VAO);
// bind vertex buffer object
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_DYNAMIC_DRAW);
// bind element buffer objects
// EBO is stored in the VAO
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
// registered VBO as the vertex attributes
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
// unbind the VAO
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
and draw method:
void Square::drawSquare()
{
// Bind the VAO so OpenGL knows to use it
glBindVertexArray(VAO);
// Draw the triangle using the GL_TRIANGLES primitive
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
}
Player and Enemy classes are inherited from square class and they have their own update method where I call in my Carte classes update methode.
void Carte::update(){
drawMap();
enemy.update(GrapMap,0);
player.update(GrapMap);
}
In draw map I simply draw my enemy and player.
void Carte::drawMap(){
enemy.drawSquare();
player.drawSquare();
for(auto & wall : walls){
wall.drawSquare();
}
}
Walls are squares too but in my case I draw therm where I want and I don't have a problem with them. at the end of every update of enemy and player after chancing vertices of them I call
glBindBuffer(GL_ARRAY_BUFFER, VAO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_DYNAMIC_DRAW);
When it was only player that I was updating it was working flawlessly. But with enemy I cant see the player but I can see that its vertices are changing accordingly to the key input of the user. When I comment out player and try to update enemy only enemy is not updating but again I can see its vertices changing as it should.
Before creating my Carte object at the main I did this:
// Vertex Shader source code
const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
" gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"}\0";
//Fragment Shader source code
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
" FragColor = vec4(0.8f, 0.3f, 0.02f, 1.0f);\n"
"}\n\0";
int main()
{
// Initialize GLFW
glfwInit();
// Tell GLFW what version of OpenGL we are using
// In this case we are using OpenGL 3.3
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
// Tell GLFW we are using the CORE profile
// So that means we only have the modern functions
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
// Create a GLFWwindow object of 800 by 800 pixels, naming it "window"
GLFWwindow* window = glfwCreateWindow(1000, 1000, "Window", NULL, NULL);
// Error check if the window fails to create
if (window == NULL)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
// Introduce the window into the current context
glfwMakeContextCurrent(window);
//Load GLAD so it configures OpenGL
gladLoadGL();
// Specify the viewport of OpenGL in the Window
// In this case the viewport goes from x = 0, y = 0, to x = 800, y = 800
//glViewport(0, 0, 1400, 1400);
// Create Vertex Shader Object and get its reference
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
// Attach Vertex Shader source to the Vertex Shader Object
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
// Compile the Vertex Shader into machine code
glCompileShader(vertexShader);
// Create Fragment Shader Object and get its reference
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
// Attach Fragment Shader source to the Fragment Shader Object
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
// Compile the Vertex Shader into machine code
glCompileShader(fragmentShader);
// Create Shader Program Object and get its reference
GLuint shaderProgram = glCreateProgram();
// Attach the Vertex and Fragment Shaders to the Shader Program
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
// Wrap-up/Link all the shaders together into the Shader Program
glLinkProgram(shaderProgram);
// Delete the now useless Vertex and Fragment Shader objects
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
In my while loop I am doing this:
// Specify the color of the background
glClearColor(0.07f, 0.13f, 0.17f, 1.0f);
// Clean the back buffer and assign the new color to it
glClear(GL_COLOR_BUFFER_BIT);
// Tell OpenGL which Shader Program we want to use
glUseProgram(shaderProgram);
int keyW = glfwGetKey(window, GLFW_KEY_W);
int keyA = glfwGetKey(window, GLFW_KEY_A);
int keyS = glfwGetKey(window, GLFW_KEY_S);
int keyD = glfwGetKey(window, GLFW_KEY_D);
carte.update();
if(keyW)
deneme.setPlayerDirection(Directions::UP);
else if(keyA)
deneme.setPlayerDirection(Directions::LEFT);
else if(keyS)
deneme.setPlayerDirection(Directions::DOWN);
else if(keyD)
deneme.setPlayerDirection(Directions::RIGHT);
// Swap the back buffer with the front buffer
glfwSwapBuffers(window);
// Take care of all GLFW events
glfwPollEvents();
I don't understand why I can't update my two objects at the same time. Why I cant draw squares as the vertices changes when there is more then one objects vertices are changing.
edit to show how I change my vertices in Player:
if(getDirection() == Directions::UP){
trans = glm::translate(trans, glm::vec3(0.0f, 0.0002f, 0.0f));
setCenter(center.first,center.second 0.0002f);
}
else if (getDirection() == Directions::LEFT){
trans = glm::translate(trans, glm::vec3(-0.0002f, 0.0f, 0.0f));
setCenter(center.first-0.0002f,center.second);
}
else if (getDirection() == Directions::DOWN){
trans = glm::translate(trans, glm::vec3(0.0f, -0.0002f, 0.0f));
setCenter(center.first,center.second-0.0002f);
}
else if (getDirection() == Directions::RIGHT){
trans = glm::translate(trans, glm::vec3(0.0002f, 0.0f, 0.0f));
setCenter(center.first 0.0002f,center.second);
}
else if (getDirection() == Directions::STOP)
trans = glm::translate(trans, glm::vec3(0.0f, 0.0f, 0.0f));
for(int i=0; i < 4; i ){
glm::vec4 tmp = trans * glm::vec4(getVertices()[i],1);
setVertices(i, tmp.x, tmp.y, tmp.z);
}
glBindBuffer(GL_ARRAY_BUFFER, VAO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_DYNAMIC_DRAW);
CodePudding user response：
This is not valid code: glBindBuffer(GL_ARRAY_BUFFER, VAO); You're attempting to bind the vertex array object to a vertex buffer location. Those are two completely different types. You probably meant to write glBindBuffer(GL_ARRAY_BUFFER, VBO); but just mistyped it.
Unless the VAO and VBO happen to have the same value, then you're either updating the wrong buffer, or no buffer at all.
CodePudding user response：
Your update code seem to be working with the wrong buffer:
glBindBuffer(GL_ARRAY_BUFFER, VAO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_DYNAMIC_DRAW);
You want to update vertices but you bind VAO instead of VBO where the later is the buffer.
From a personal experience you should write wrappers around those classes to prevent exactly such scenarios.