因此，我开始使用 OpenGL 与 glew 和 GLFW 来创建游戏引擎，在开始使用着色器时我几乎立即遇到了问题：
它们没有被使用或者即使被使用也没有任何效果。
我一直在用大量其他示例检查我的代码，它们都匹配，没有任何看起来不合适的地方，我开始失去想法和耐心（我已经尝试找出原因近一个月了）有了这个。
我的主要核心代码在这里：
#include "headers/Default.hpp"
//Window width and height variables
int windowWidth = 800;
int windowHeight = 600;
float Aspect = (float)windowWidth / (float)windowHeight;
//Buffer width and buffer height
int bufferWidth;
int bufferHeight;
double deltaTime;
double currentTime;
double newTime;
void CalculateDelta()
{
newTime = glfwGetTime();
deltaTime = newTime - currentTime;
currentTime = newTime;
}
//A call back function to get the window size
void UpdateWindowSize(GLFWwindow* window, int width, int height)
{
windowWidth = width;
windowHeight = height;
Aspect = (float)windowWidth / (float)windowHeight;
}
void UpdateFrameBufferSize(GLFWwindow* window, int width, int height)
{
bufferWidth = width;
bufferHeight = height;
}
//Starts on startup and creates an window context and starts the rendering loop
int main()
{
//Creates an engine startup log to keep
CreateStartupLog();
if (!glewInit())
{
WriteStartupLog("ERROR: GLEW failed to start\n");
return 1;
}
else
{
WriteStartupLog("INFO: GLEW initiated!\n");
}
//If glfw is not initiated for whatever reason we return an error
if (!glfwInit())
{
WriteStartupLog("ERROR: GLFW failed to start\n");
return 1;
}
else
{
WriteStartupLog("INFO: GLFW initiated!\n");
}
////////////////////////////////////////////////////////////////
// Window Section //
////////////////////////////////////////////////////////////////
//glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
//glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
//glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
//Gets the primary monitor of the PC and tells OpenGL to use that monitor
GLFWmonitor* monitor = glfwGetPrimaryMonitor();
const GLFWvidmode* videoMode = glfwGetVideoMode(monitor);
//Creates a GLFW window context that we can work with
GLFWwindow* gameWindow = glfwCreateWindow(windowWidth/*videoMode->width*/, windowHeight/*videoMode->height*/, "FireTech Engine", NULL/*monitor*/, NULL);
//If the game window is not able to be created, prints an error and terminates the program
if (!gameWindow)
{
WriteStartupLog("ERROR: GLFW could not create a window\n");
glfwTerminate();
return 1;
}
else
{
WriteStartupLog("INFO: GLFW created a window!\n\n");
}
//Makes the current context
glfwMakeContextCurrent(gameWindow);
//Sets the window callback function for size
glfwSetWindowSizeCallback(gameWindow, UpdateWindowSize);
glfwSetFramebufferSizeCallback(gameWindow, UpdateFrameBufferSize);
//Initiate GLEW
glewExperimental = GL_TRUE;
glewInit();
////////////////////////////////////////////////////////////////
// Functions to set up various systems of the game engine //
////////////////////////////////////////////////////////////////
//Calls function to create a log file for the game engine
CreateEngineLog();
//Calls the function to compile the default shaders
CompileDefaultShader();
//Calls the function to get and print out hardware and OpenGL version
//PrintHardwareInfo();
////////////////////////////////////////////////////////////////
// Game Code //
////////////////////////////////////////////////////////////////
Sprite testSprite;
//Rendering loop
while (!glfwWindowShouldClose(gameWindow))
{
CalculateDelta();
glClearColor(0.3, 0.6, 1.0, 0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
//Viewport and ortho settings
glViewport(0, 0, windowWidth, windowHeight);
glOrtho(-1, 1, -1 / Aspect, 1 / Aspect, 0, 1);
//Draw a sprite
if (GLFW_PRESS == glfwGetKey(gameWindow, GLFW_KEY_F2))
{
testSprite.DebugDraw();
}
else
{
testSprite.Draw();
}
//Draws the stuff we just rendered
glfwSwapBuffers(gameWindow);
glLoadIdentity();
//Polls different events, like input for example
glfwPollEvents();
if (GLFW_PRESS == glfwGetKey(gameWindow, GLFW_KEY_F1))
{
int fps = GetFPS();
printf("FPS: ");
printf("%d\n", fps);
printf("Frequency: ");
printf("%f\n", 1/double(fps));
}
if (GLFW_PRESS == glfwGetKey(gameWindow, GLFW_KEY_ESCAPE))
{
glfwSetWindowShouldClose(gameWindow, 1);
}
}
glfwTerminate();
WriteEngineLog("PROGRAM EXITED: Window closed");
return 0;
}
这是shader.cpp代码：
#include "../headers/Default.hpp"
string ReadShaderFile(char* path)
{
ifstream shaderFile;
shaderFile.open(path, std::ifstream::in);
string output;
if (shaderFile.is_open())
{
printf("Opened shader file located at: \"%s\"\n", path);
while (!shaderFile.eof())
{
output += shaderFile.get();
}
printf("Successfully read shader file located at: \"%s\"\n", path);
}
else
{
WriteEngineLog("ERROR: Could not read shader file!\n");
}
shaderFile.close();
return output;
}
Shader::Shader()
{
WriteEngineLog("WARNING: There was no path to any GLSL Shader files\n");
}
Shader::Shader(char* VertexShaderPathIn, char* FragmentShaderPathIn)
{
string vertexShaderString = ReadShaderFile(VertexShaderPathIn);
string fragmentShaderString = ReadShaderFile(FragmentShaderPathIn);
//Prints out the string to show the shader's code
printf("\n%s\n", vertexShaderString.c_str());
printf("\n%s\n", fragmentShaderString.c_str());
//Creates the GLchars needed to input the shader code
const GLchar* vertex_shader = vertexShaderString.c_str();
const GLchar* fragment_shader = fragmentShaderString.c_str();
//Creates a vertex shader and compiles it
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
WriteEngineLog("Blank vertex shader created\n");
glShaderSource(vertexShader, 1, &vertex_shader, NULL);
WriteEngineLog("Vertex shader given source\n");
glCompileShader(vertexShader);
//Compilation error checking begions here
GLint isVertexCompiled = 0;
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &isVertexCompiled);
if (isVertexCompiled == GL_FALSE)
{
//Gets the length of the log
GLint maxLength = 0;
glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &maxLength);
//Creates and writes the log to the errorLog
GLchar* errorLog = (GLchar*)malloc(maxLength);
glGetShaderInfoLog(vertexShader, maxLength, &maxLength, &errorLog[0]);
//Writes to the engine log with the shader error
WriteEngineLog("ERROR: Vertex shader failed to compile!\n");
printf("%s\n", (char*)errorLog);
//Frees the errorLog allocation
free(errorLog);
//Deletes the shader so it doesn't leak
glDeleteShader(vertexShader);
WriteEngineLog("ERROR: Aborting shader creation.\n");
return;
}
//Writes in the engine log to report successful compilation
WriteEngineLog("Vertex shader successfully compiled!\n");
//Creates a fragment shader
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
WriteEngineLog("Blank fragment shader created\n");
glShaderSource(fragmentShader, 1, &fragment_shader, NULL);
WriteEngineLog("Fragment shader given source\n");
glCompileShader(fragmentShader);
//Compilation error checking begions here
GLint isFragmentCompiled = 0;
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &isFragmentCompiled);
if (isFragmentCompiled == GL_FALSE)
{
//Gets the length of the log
GLint maxLength = 0;
glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &maxLength);
//Creates and writes the log to the errorLog
GLchar* errorLog = (GLchar*)malloc(maxLength);
glGetShaderInfoLog(vertexShader, maxLength, &maxLength, &errorLog[0]);
WriteEngineLog("ERROR: Fragment shader failed to compile\n");
printf("%s\n", (char*)errorLog);
//Frees the errorLog allocation
free(errorLog);
//Deletes the shader so it doesn't leak
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
WriteEngineLog("ERROR: Aborting shader creation.\n");
return;
}
//Writes in the engine log to report successful compilation
WriteEngineLog("Fragment shader successfully compiled!\n");
//Creates the final shader product
this->Program = glCreateProgram();
WriteEngineLog("Blank shader created\n");
glAttachShader(this->Program, vertexShader);
WriteEngineLog("Attatched Vertex shader to the shader\n");
glAttachShader(this->Program, fragmentShader);
WriteEngineLog("Attatched Fragment shader to the shader\n");
glLinkProgram(this->Program);
/*GLint isLinked = 0;
glGetProgramiv(this->Program, GL_LINK_STATUS, (int*)&isLinked);
if (isLinked == GL_FALSE)
{
//Gets the lngth of the shader info log
GLint maxLength = 0;
glGetProgramInfolog(ShaderOut, GL_INFO_LOG_LENGTH, &maxLength);
//Gets and puts the actual log into a GLchar
std::vector<GLchar> infoLog(maxLength);
glGetProgramInfoLog(ShaderOut, maxLength, &maxLength, &infoLog[0]);
//Deletes programs and shaders so they don't leak
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
WriteEngineLog((string)infoLog);
return;
}*/
WriteEngineLog("Shader linked!\n\n");
WriteEngineLog("INFO: Shader created!\n");
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
}
void Shader::Use()
{
glUseProgram(this->Program);
}
这是quad.cpp代码：
#include "../headers/Default.hpp"
Quad::Quad()
{
position.x = 0;
position.y = 0;
scale.x = 1;
scale.y = 1;
VertexArray = CreateVertexArray();
}
//Quad constructor with one arg
Quad::Quad(Vector2 Position)
{
position = Position;
VertexArray = CreateVertexArray();
}
//Quad constructor with two args
Quad::Quad(Vector2 Position, Vector2 Scale)
{
position = Position;
scale = Scale;
VertexArray = CreateVertexArray();
}
GLuint Quad::CreateVertexArray()
{
GLfloat Vertices[] =
{
//VERTICES //COLORS //TEXCOORDS
0.5f, 0.5f, 0.0f, 0.0f, 0.0f, 0.0f, //1.0f, 1.0f, //Top Right Vertice
0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, //1.0f, 0.0f, //Top Left Vertice
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f//, 0.0f, 0.0f //Bottom Left Vertice
};
GLuint vbo, vao;
glGenVertexArrays(1, &vao);
glGenBuffers(1, &vbo);
glBindVertexArray(vao);
//Copy vertices into the buffer
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW);
//Attribute Pointers
//Position attribute
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), (GLvoid*)0);
glEnableVertexAttribArray(0);
//Color attribute
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
glEnableVertexAttribArray(1);
//Unbinds the VAO
glBindVertexArray(0);
return vao;
}
//Quad debug drawing function
void Quad::DebugDraw()
{
//Use the default shader
DefaultShader.Use();
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glBindVertexArray(VertexArray);
// draw points 0-3 from the currently bound VAO with current in-use shader
glDrawArrays(GL_TRIANGLES, 0, 3);
//glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0); //CAUSING A CRASH AT THE MOMENT
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
//Unbinds the VAO
glBindVertexArray(0);
}
这是sprite.cpp代码：
#include "../headers/Default.hpp"
Sprite::Sprite()
{
position.x = 0;
position.y = 0;
}
Sprite::Sprite(Texture tex)
{
defaultTexture = tex;
currentTexture = tex;
}
Sprite::Sprite(Texture tex, Vector2 pos)
{
defaultTexture = tex;
currentTexture = tex;
position = pos;
}
Sprite::Sprite(Texture tex, Vector2 pos, Vector2 Scale)
{
defaultTexture = tex;
currentTexture = tex;
position = pos;
scale = Scale;
}
void Sprite::Draw()
{
//Binds the default shader again
glBindVertexArray(VertexArray);
//Use the default shader
DefaultShader.Use();
// draw points 0-3 from the currently bound VAO with current in-use shader
glDrawArrays(GL_TRIANGLES, 0, 3);
glBindVertexArray(0);
}
这是我的顶点着色器和片段着色器代码（按顺序）：
//Vertex Shader
#version 330 core
layout (location = 0) in vec3 position; // The position variable has attribute position 0
layout (location = 1) in vec3 color;
out vec3 ourColor;
void main()
{
gl_Position = vec4(position, 1.0f); // See how we directly give a vec3 to vec4's constructor
ourColor = color;
}
//Fragment shader
#version 330 core
in vec3 ourColor;
out vec4 color;
void main()
{
color = ourColor;
}
我收到一条警告，指出我的着色器未编译...错误是顶点着色器的第 0 行有一个非 ASCII 字符。
