Cześć. Chcę zrobić celownik w grze w OpenGL i próbuję go stworzyć. Czytałem, że można to zrobić za pomocą wyświetlenia linii. Nie wiem tylko jak je narysować. Próbuję zrobić to tak jak rysowałem sześcian, ale nie wychodzi. Dlaczego to nie działa? I przy okazji jak zrobić aby linie były z kamerą na środku ekranu, wystarczy zmienić ich pozycję na pozycję kamery? Dzięki za odpowiedzi.
C++
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <glm.hpp>
#include <gtc/matrix_transform.hpp>
#include <gtc/type_ptr.hpp>
#include <iostream>
#include <fstream>
#include <string>
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
glm::vec3 cameraPos = glm::vec3(0.0f, 0.0f, 3.0f);
glm::vec3 cameraFront = glm::vec3(0.0f, 0.0f, -1.0f);
glm::vec3 cameraUp = glm::vec3(0.0f, 1.0f, 0.0f);
float deltaTime = 0.0f;
float lastFrame = 0.0f;
float pitch;
float yaw;
float lastX = 600, lastY = 360;
float fov = 45.0f;
bool firstMouse = false;
static unsigned int CompileShader(unsigned int type, std::string source)
{
unsigned int id = glCreateShader(type);
const char* src = source.c_str();
glShaderSource(id, 1, &src, nullptr);
glCompileShader(id);
int result;
glGetShaderiv(id, GL_COMPILE_STATUS, &result);
if (result == GL_FALSE)
{
int length;
glGetShaderiv(id, GL_INFO_LOG_LENGTH, &length);
char* message = (char*)_malloca(length * sizeof(char));
glGetShaderInfoLog(id, length, &length, message);
std::cout << "Failed to compile " << (type == GL_VERTEX_SHADER ? "vertex" : "fragment") << "shader" << std::endl;
std::cout << message << std::endl;
glDeleteShader(id);
return 0;
}
return id;
}
static unsigned int CreateShader(const std::string& vertexShader, const std::string fragmentShader)
{
unsigned int program = glCreateProgram();
unsigned int vs = CompileShader(GL_VERTEX_SHADER, vertexShader);
unsigned int fs = CompileShader(GL_FRAGMENT_SHADER, fragmentShader);
glAttachShader(program, vs);
glAttachShader(program, fs);
glLinkProgram(program);
glDeleteShader(vs);
glDeleteShader(fs);
return program;
}
std::string readFromFile(const char* pathToFile)
{
std::string content;
std::ifstream fileStream(pathToFile, std::ios::in);
if (!fileStream.is_open()) {
std::cerr << "Could not read file " << pathToFile << ". File does not exist." << std::endl;
return "";
}
std::string line;
while (std::getline(fileStream, line)) {
content.append(line + "\n");
}
fileStream.close();
std::cout << content << std::endl;
return content;
}
void processInput(GLFWwindow* window)
{
float currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
float cameraSpeed = 2.5f * deltaTime; // dopasuj do swoich potrzeb
if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
cameraPos += cameraSpeed * cameraFront;
if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
cameraPos -= cameraSpeed * cameraFront;
if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
cameraPos -= glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed;
if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
cameraPos += glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed;
}
void mouse_callback(GLFWwindow* window, double xpos, double ypos)
{
if (firstMouse) // ta zmienna bool jest początkowo ustawiona na true
{
lastX = xpos;
lastY = ypos;
firstMouse = false;
}
GLfloat xoffset = xpos - lastX;
GLfloat yoffset = lastY - ypos;
lastX = xpos;
lastY = ypos;
GLfloat sensitivity = 0.05;
xoffset *= sensitivity;
yoffset *= sensitivity;
yaw += xoffset;
pitch += yoffset;
if (pitch > 89.0f)
pitch = 89.0f;
if (pitch < -89.0f)
pitch = -89.0f;
glm::vec3 front;
front.x = cos(glm::radians(yaw)) * cos(glm::radians(pitch));
front.y = sin(glm::radians(pitch));
front.z = sin(glm::radians(yaw)) * cos(glm::radians(pitch));
cameraFront = glm::normalize(front);
}
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{
if (fov >= 1.0f && fov <= 45.0f)
fov -= yoffset;
if (fov <= 1.0f)
fov = 1.0f;
if (fov >= 45.0f)
fov = 45.0f;
}
int main(void)
{
GLFWwindow* window;
/* Initialize the library */
if (!glfwInit())
return -1;
/* Create a windowed mode window and its OpenGL context */
window = glfwCreateWindow(1200, 720, "Shoot The Cube!", NULL, NULL);
if (!window)
{
glfwTerminate();
return -1;
}
/* Make the window's context current */
glfwMakeContextCurrent(window);
if (glewInit() != GLEW_OK)
std::cout << "Error" << std::endl;
std::cout << glGetString(GL_VERSION) << std::endl;
glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
glfwSetCursorPosCallback(window, mouse_callback);
float vertices[] = {
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
0.5f, -0.5f, -0.5f, 1.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
-0.5f, 0.5f, 0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, -0.5f, 1.0f, 1.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f
};
unsigned int VBO;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
glEnableVertexAttribArray(1);
float crosshairVertices[] = {
200.0f, 200.0f, 200.0f,
200.0f, 200.0f, 200.0f
};
unsigned int CVB;
glGenBuffers(1, &CVB);
glBindBuffer(GL_ARRAY_BUFFER, CVB);
glBufferData(GL_ARRAY_BUFFER, sizeof(crosshairVertices), crosshairVertices, GL_STATIC_DRAW);
glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(2);
std::string vertexShaderSource = readFromFile("vertexShader.shader");
std::string fragmentShaderSource = readFromFile("fragmentShader.shader");
unsigned int shaderProgram = CreateShader(vertexShaderSource, fragmentShaderSource);
glUseProgram(shaderProgram);
unsigned int bodyTex;
glGenTextures(1, &bodyTex);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, bodyTex);
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);
stbi_set_flip_vertically_on_load(true);
int width, height, nrChannels;
unsigned char* data = stbi_load("C:/Users/Antoni/Desktop/container.jpg", &width, &height, &nrChannels, 0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
stbi_image_free(data);
unsigned int faceTex;
glGenTextures(1, &faceTex);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, faceTex);
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);
data = stbi_load("C:/Users/Antoni/Desktop/face.png", &width, &height, &nrChannels, 0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
stbi_image_free(data);
glUniform1i(glGetUniformLocation(shaderProgram, "playerBody"), 0);
glUniform1i(glGetUniformLocation(shaderProgram, "playerFace"), 1);
glEnable(GL_DEPTH_TEST);
/* Loop until the user closes the window */
while (!glfwWindowShouldClose(window))
{
/* Render here */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glClearColor(0.2, 0.5, 1.0, 0.5);
processInput(window);
glfwSetScrollCallback(window, scroll_callback);
float currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
glm::mat4 lookAt(1.0f);
unsigned int lookAtLoc = glGetUniformLocation(shaderProgram, "lookAt");
lookAt = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp);
glUniformMatrix4fv(lookAtLoc, 1, GL_FALSE, glm::value_ptr(lookAt));
glm::mat4 projection(1.0f);
projection = glm::perspective(glm::radians(fov), (float)1200 / (float)720, 0.1f, 100.0f);
unsigned int projectionLoc = glGetUniformLocation(shaderProgram, "projection");
glUniformMatrix4fv(projectionLoc, 1, GL_FALSE, glm::value_ptr(projection));
glDrawArrays(GL_TRIANGLES, 0, 36);
glDrawArrays(GL_LINES, 0, 2);
/* Swap front and back buffers */
glfwSwapBuffers(window);
/* Poll for and process events */
glfwPollEvents();
}
glfwTerminate();
return 0;
}
Vertex shader
#version 330 core
layout(location = 0) in vec3 PlayerPositions;
layout(location = 1) in vec2 aCords;
layout(location = 2) in vec3 aLines;
out vec2 texCords;
uniform mat4 projection;
uniform mat4 lookAt;
void main()
{
gl_Position = projection * lookAt * vec4(PlayerPositions, 1.0);
texCords = aCords;
}
Fragment shader
#version 330 core
out vec4 Color;
in vec2 texCords;
uniform sampler2D playerBody;
uniform sampler2D playerFace;
void main()
{
Color = mix(texture(playerBody, texCords), texture(playerFace, texCords), 0.2);
}
