我想用 GLFW 在 Linux 上用 C++ 制作 3D 游戏，很高兴。但正确的 3D 视角无法正常工作，我不明白为什么。
这应该绘制一个橙色三角形，当你远离时它会变小，当你靠近时它会变大，但它永远不会改变大小，只会最终到达剪切平面并消失。
另外，如果这有帮助的话，如果我的三角形的 z 值为 0，即使我来回移动也看不到它。
这是代码：
#include <iostream>
#include "glad/glad.h"
#include "GLFW/glfw3.h"
#include "glm/glm.hpp"
#include "glm/gtc/matrix_transform.hpp"
#include "glm/gtc/type_ptr.hpp"
// Vertex Shader source code
const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"\n"
"uniform mat4 model;\n"
"uniform mat4 view;\n"
"uniform mat4 proj;\n"
"void main()\n"
"{\n"
" gl_Position = model * view * proj * vec4(aPos, 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 SCREEN_WIDTH=800;
int SCREEN_HEIGHT=600;
void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
glViewport(0, 0, width, height);
SCREEN_WIDTH=width;
SCREEN_HEIGHT=height;
}
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 width by height pixels, naming it "3D C++"
GLFWwindow* window = glfwCreateWindow(SCREEN_WIDTH, SCREEN_HEIGHT, "3D C++", 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 = width, y = height
glViewport(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
// 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);
// Vertices coordinates
GLfloat vertices[] =
{
1.0f, 0.0f, 0.0f, // Lower left corner
-1.0f, 0.0f, 0.0f, // Lower right corner
0.0f, 1.73205080757f, 0.0f // Upper corner
};
// Create reference containers for the Vartex Array Object and the Vertex Buffer Object
GLuint VAO, VBO;
// Generate the VAO and VBO with only 1 object each
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
// Make the VAO the current Vertex Array Object by binding it
glBindVertexArray(VAO);
// Bind the VBO specifying it's a GL_ARRAY_BUFFER
glBindBuffer(GL_ARRAY_BUFFER, VBO);
// Introduce the vertices into the VBO
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
// Configure the Vertex Attribute so that OpenGL knows how to read the VBO
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
// Enable the Vertex Attribute so that OpenGL knows to use it
glEnableVertexAttribArray(0);
// Bind both the VBO and VAO to 0 so that we don't accidentally modify the VAO and VBO we created
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
glm::vec3 cam = glm::vec3(0.0f,0.0f,0.0f);
glm::mat4 model = glm::mat4(1.0f);
glm::mat4 view = glm::lookAt(cam,glm::vec3(cam.x,cam.y,cam.z-3.0f),glm::vec3(0.0f,1.0f,0.0f));
//view = glm::translate(view, cam);
glm::mat4 proj = glm::perspective(glm::radians(45.0f), (float)SCREEN_WIDTH/(float)SCREEN_HEIGHT, 0.1f, 100.0f);
// Main while loop
while (!glfwWindowShouldClose(window))
{
if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) {
glfwSetWindowShouldClose(window, true);
}
if (glfwGetKey(window, GLFW_KEY_DOWN) == GLFW_PRESS) cam.z-=0.01f;
if (glfwGetKey(window, GLFW_KEY_UP) == GLFW_PRESS) cam.z+=0.01f;
if (glfwGetKey(window, GLFW_KEY_LEFT) == GLFW_PRESS) cam.x-=0.01f;
if (glfwGetKey(window, GLFW_KEY_RIGHT) == GLFW_PRESS) cam.x+=0.01f;
if (glfwGetKey(window, GLFW_KEY_Q) == GLFW_PRESS) cam.y-=0.01f;
if (glfwGetKey(window, GLFW_KEY_E) == GLFW_PRESS) cam.y+=0.01f;
std::cout << cam.x << " , " << cam.y << " , " << cam.z << std::endl;
model = glm::mat4(1.0f);
view = glm::lookAt(cam,glm::vec3(cam.x,cam.y,cam.z-3.0f),glm::vec3(0.0f,1.0f,0.0f));
//view = glm::translate(view, cam);
proj = glm::perspective(glm::radians(45.0f), (float)SCREEN_WIDTH/(float)SCREEN_HEIGHT, 0.1f, 100.0f);
int modelLoc = glGetUniformLocation(shaderProgram, "model");
glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
int viewLoc = glGetUniformLocation(shaderProgram, "view");
glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
int projLoc = glGetUniformLocation(shaderProgram, "proj");
glUniformMatrix4fv(projLoc, 1, GL_FALSE, glm::value_ptr(proj));
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);
// Bind the VAO so OpenGL knows to use it
glBindVertexArray(VAO);
// Draw the triangle using the GL_TRIANGLES primitive
glDrawArrays(GL_TRIANGLES, 0, 3);
// Swap the back buffer with the front buffer
glfwSwapBuffers(window);
// Take care of all GLFW events
glfwPollEvents();
}
// Delete all the objects we've created
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
glDeleteProgram(shaderProgram);
// Delete window before ending the program
glfwDestroyWindow(window);
// Terminate GLFW before ending the program
glfwTerminate();
return 0;
}
所有帮助都会有益。 提前致谢。
改变：
gl_Position = model * view * proj * vec4(aPos, 1.0)));至：
gl_Position = proj * view * model * vec4(aPos, 1.0);有效。 有点奇怪，但是谢谢 user253751 ！