Step 1: Create Project Directory Шаг 1: Создание директории проекта

Create a workspace folder and a new directory for your GLAD-enabled triangle project: Создайте рабочую папку для проектов и новую директорию для вашего проекта треугольника с GLAD:

Windows (Command Prompt / PowerShell)

mkdir C:\projects\draw-triangle-sdl3-glm-glad-opengl-desktop
cd C:\projects\draw-triangle-sdl3-glm-glad-opengl-desktop

Ubuntu (Terminal)

mkdir -p ~/projects/draw-triangle-sdl3-glm-glad-opengl-desktop
cd ~/projects/draw-triangle-sdl3-glm-glad-opengl-desktop

Step 2: Create Source Files (main.cpp & CMakeLists.txt) Шаг 2: Создание исходных файлов (main.cpp и CMakeLists.txt)

Create these files using Notepad / Sublime Text on Windows, or nano in Ubuntu terminal: Создайте эти файлы через Блокнот / Sublime Text в Windows или с помощью nano в терминале Ubuntu:

Windows (Terminal / Notepad)

notepad main.cpp
notepad CMakeLists.txt

Ubuntu (Terminal / Nano)

nano main.cpp
nano CMakeLists.txt

1A. File Contents for main.cpp (Classic Loop) 1A. Содержимое файла main.cpp (Классический цикл)

#include <glad/glad.h> // Must be included before SDL headers
#include <SDL3/SDL.h>
#include <SDL3/SDL_main.h>

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

// Vertex Shader source code
const char* vertexShaderSource = R"(
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aColor;

out vec3 ourColor;
uniform mat4 uMVP;

void main() {
    gl_Position = uMVP * vec4(aPos, 1.0);
    ourColor = aColor;
}
)";

// Fragment Shader source code
const char* fragmentShaderSource = R"(
#version 330 core
out vec4 FragColor;
in vec3 ourColor;

void main() {
    FragColor = vec4(ourColor, 1.0);
}
)";

GLuint createShaderProgram(const char* vertexSrc, const char* fragmentSrc) {
    GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexShader, 1, &vertexSrc, nullptr);
    glCompileShader(vertexShader);

    GLint success;
    char infoLog[512];
    glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
    if (!success) {
        glGetShaderInfoLog(vertexShader, 512, nullptr, infoLog);
        SDL_Log("Vertex Shader Compilation Failed: %s", infoLog);
    }

    GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShader, 1, &fragmentSrc, nullptr);
    glCompileShader(fragmentShader);

    glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
    if (!success) {
        glGetShaderInfoLog(fragmentShader, 512, nullptr, infoLog);
        SDL_Log("Fragment Shader Compilation Failed: %s", infoLog);
    }

    GLuint shaderProgram = glCreateProgram();
    glAttachShader(shaderProgram, vertexShader);
    glAttachShader(shaderProgram, fragmentShader);
    glLinkProgram(shaderProgram);

    glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
    if (!success) {
        glGetProgramInfoLog(shaderProgram, 512, nullptr, infoLog);
        SDL_Log("Shader Program Link Failed: %s", infoLog);
    }

    glDeleteShader(vertexShader);
    glDeleteShader(fragmentShader);

    return shaderProgram;
}

int main(int argc, char* argv[]) {
    if (!SDL_Init(SDL_INIT_VIDEO)) {
        SDL_Log("SDL Initialization failed: %s", SDL_GetError());
        return -1;
    }

    // Configure OpenGL 3.3 Core Profile attributes
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);

    SDL_Window* window = SDL_CreateWindow("SDL3 GLM GLAD OpenGL 3.3 Triangle (Classic)", 800, 450, SDL_WINDOW_OPENGL);
    if (!window) {
        SDL_Log("Window creation failed: %s", SDL_GetError());
        SDL_Quit();
        return -1;
    }

    SDL_GLContext glContext = SDL_GL_CreateContext(window);
    if (!glContext) {
        SDL_Log("OpenGL context creation failed: %s", SDL_GetError());
        SDL_DestroyWindow(window);
        SDL_Quit();
        return -1;
    }

    SDL_GL_MakeCurrent(window, glContext);
    SDL_GL_SetSwapInterval(1); // Enable VSync

    // Initialize GLAD function pointers using SDL_GL_GetProcAddress
    if (!gladLoadGLLoader((GLADloadproc)SDL_GL_GetProcAddress)) {
        SDL_Log("Failed to initialize GLAD");
        SDL_GL_DestroyContext(glContext);
        SDL_DestroyWindow(window);
        SDL_Quit();
        return -1;
    }

    GLuint shaderProgram = createShaderProgram(vertexShaderSource, fragmentShaderSource);

    // Vertex data: Position (X, Y, Z) and Color (R, G, B)
    float vertices[] = {
        // Positions         // Colors
         0.0f,  0.5f, 0.0f,  1.0f, 0.0f, 0.0f, // Top (Red)
        -0.5f, -0.5f, 0.0f,  0.0f, 1.0f, 0.0f, // Bottom Left (Green)
         0.5f, -0.5f, 0.0f,  0.0f, 0.0f, 1.0f  // Bottom Right (Blue)
    };

    GLuint VAO, VBO;
    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);

    glBindVertexArray(VAO);

    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    // Position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    // Color attribute
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);

    // Setup GLM Matrices
    glm::vec3 clearColorVec(0.1f, 0.12f, 0.15f);
    glm::mat4 projection = glm::perspective(glm::radians(45.0f), 800.0f / 450.0f, 0.1f, 100.0f);
    glm::mat4 view = glm::lookAt(glm::vec3(0.0f, 0.0f, 3.0f), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 1.0f, 0.0f));
    glm::mat4 model = glm::mat4(1.0f);
    glm::mat4 mvp = projection * view * model;

    GLint mvpLoc = glGetUniformLocation(shaderProgram, "uMVP");

    bool running = true;
    while (running) {
        SDL_Event event;
        while (SDL_PollEvent(&event)) {
            if (event.type == SDL_EVENT_QUIT) {
                running = false;
            }
        }

        // Clear screen
        glClearColor(clearColorVec.r, clearColorVec.g, clearColorVec.b, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        // Draw Triangle
        glUseProgram(shaderProgram);
        glUniformMatrix4fv(mvpLoc, 1, GL_FALSE, glm::value_ptr(mvp));

        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 3);

        SDL_GL_SwapWindow(window);
    }

    // Cleanup resources
    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glDeleteProgram(shaderProgram);

    SDL_GL_DestroyContext(glContext);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}

1B. File Contents for main.cpp (SDL3 Callbacks API) 1B. Содержимое файла main.cpp (SDL3 Callbacks API)

#define SDL_MAIN_USE_CALLBACKS 1
#include <glad/glad.h> // Must be included before SDL headers
#include <SDL3/SDL.h>
#include <SDL3/SDL_main.h>

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

// Vertex Shader source code
const char* vertexShaderSource = R"(
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aColor;

out vec3 ourColor;
uniform mat4 uMVP;

void main() {
    gl_Position = uMVP * vec4(aPos, 1.0);
    ourColor = aColor;
}
)";

// Fragment Shader source code
const char* fragmentShaderSource = R"(
#version 330 core
out vec4 FragColor;
in vec3 ourColor;

void main() {
    FragColor = vec4(ourColor, 1.0);
}
)";

GLuint createShaderProgram(const char* vertexSrc, const char* fragmentSrc) {
    GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexShader, 1, &vertexSrc, nullptr);
    glCompileShader(vertexShader);

    GLint success;
    char infoLog[512];
    glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
    if (!success) {
        glGetShaderInfoLog(vertexShader, 512, nullptr, infoLog);
        SDL_Log("Vertex Shader Compilation Failed: %s", infoLog);
    }

    GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShader, 1, &fragmentSrc, nullptr);
    glCompileShader(fragmentShader);

    glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
    if (!success) {
        glGetShaderInfoLog(fragmentShader, 512, nullptr, infoLog);
        SDL_Log("Fragment Shader Compilation Failed: %s", infoLog);
    }

    GLuint shaderProgram = glCreateProgram();
    glAttachShader(shaderProgram, vertexShader);
    glAttachShader(shaderProgram, fragmentShader);
    glLinkProgram(shaderProgram);

    glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
    if (!success) {
        glGetProgramInfoLog(shaderProgram, 512, nullptr, infoLog);
        SDL_Log("Shader Program Link Failed: %s", infoLog);
    }

    glDeleteShader(vertexShader);
    glDeleteShader(fragmentShader);

    return shaderProgram;
}

struct AppState {
    SDL_Window* window = nullptr;
    SDL_GLContext glContext = nullptr;
    GLuint shaderProgram = 0;
    GLuint VAO = 0;
    GLuint VBO = 0;
    GLint mvpLoc = -1;
    glm::mat4 mvp = glm::mat4(1.0f);
    glm::vec3 clearColorVec = glm::vec3(0.1f, 0.12f, 0.15f);
};

SDL_AppResult SDL_AppInit(void** appstate, int argc, char* argv[]) {
    if (!SDL_Init(SDL_INIT_VIDEO)) {
        SDL_Log("SDL Initialization failed: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);

    AppState* state = new AppState();
    *appstate = state;

    state->window = SDL_CreateWindow("SDL3 GLM GLAD OpenGL 3.3 Triangle (Callbacks)", 800, 450, SDL_WINDOW_OPENGL);
    if (!state->window) {
        SDL_Log("Window creation failed: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }

    state->glContext = SDL_GL_CreateContext(state->window);
    if (!state->glContext) {
        SDL_Log("OpenGL context creation failed: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }

    SDL_GL_MakeCurrent(state->window, state->glContext);
    SDL_GL_SetSwapInterval(1);

    // Initialize GLAD
    if (!gladLoadGLLoader((GLADloadproc)SDL_GL_GetProcAddress)) {
        SDL_Log("Failed to initialize GLAD");
        return SDL_APP_FAILURE;
    }

    state->shaderProgram = createShaderProgram(vertexShaderSource, fragmentShaderSource);

    float vertices[] = {
        // Positions         // Colors
         0.0f,  0.5f, 0.0f,  1.0f, 0.0f, 0.0f,
        -0.5f, -0.5f, 0.0f,  0.0f, 1.0f, 0.0f,
         0.5f, -0.5f, 0.0f,  0.0f, 0.0f, 1.0f
    };

    glGenVertexArrays(1, &state->VAO);
    glGenBuffers(1, &state->VBO);

    glBindVertexArray(state->VAO);

    glBindBuffer(GL_ARRAY_BUFFER, state->VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);

    glm::mat4 projection = glm::perspective(glm::radians(45.0f), 800.0f / 450.0f, 0.1f, 100.0f);
    glm::mat4 view = glm::lookAt(glm::vec3(0.0f, 0.0f, 3.0f), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 1.0f, 0.0f));
    glm::mat4 model = glm::mat4(1.0f);
    state->mvp = projection * view * model;

    state->mvpLoc = glGetUniformLocation(state->shaderProgram, "uMVP");

    return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppEvent(void* appstate, SDL_Event* event) {
    if (event->type == SDL_EVENT_QUIT) {
        return SDL_APP_SUCCESS;
    }
    return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppIterate(void* appstate) {
    auto* state = static_cast<AppState*>(appstate);

    glClearColor(state->clearColorVec.r, state->clearColorVec.g, state->clearColorVec.b, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    glUseProgram(state->shaderProgram);
    glUniformMatrix4fv(state->mvpLoc, 1, GL_FALSE, glm::value_ptr(state->mvp));

    glBindVertexArray(state->VAO);
    glDrawArrays(GL_TRIANGLES, 0, 3);

    SDL_GL_SwapWindow(state->window);

    return SDL_APP_CONTINUE;
}

void SDL_AppQuit(void* appstate, SDL_AppResult result) {
    if (appstate) {
        auto* state = static_cast<AppState*>(appstate);

        if (state->VAO) glDeleteVertexArrays(1, &state->VAO);
        if (state->VBO) glDeleteBuffers(1, &state->VBO);
        if (state->shaderProgram) glDeleteProgram(state->shaderProgram);

        if (state->glContext) {
            SDL_GL_DestroyContext(state->glContext);
        }
        if (state->window) {
            SDL_DestroyWindow(state->window);
        }
        delete state;
    }
    SDL_Quit();
}

2. File Contents for CMakeLists.txt 2. Содержимое файла CMakeLists.txt

cmake_minimum_required(VERSION 3.21)

# Default to Debug if CMAKE_BUILD_TYPE is not set via command line
if(NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE "Debug")
endif()

project(draw-triangle-sdl3-glm-glad-opengl-desktop CXX C)

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# -----------------------------------------------------------------------------
# Locate System OpenGL Package
# -----------------------------------------------------------------------------
find_package(OpenGL REQUIRED)

# -----------------------------------------------------------------------------
# Locate SDL3 Package via Custom Paths
# -----------------------------------------------------------------------------
if(WIN32)
    set(SDL3_DIR "C:/libs/sdl3-3.4.16-mingw/lib/cmake/SDL3")
else()
    set(SDL3_DIR "$ENV{HOME}/libs/sdl3-3.4.16-ubuntu/lib/cmake/SDL3")
endif()

find_package(SDL3 REQUIRED CONFIG)

# -----------------------------------------------------------------------------
# Set Include Path for Header-Only GLM Library
# -----------------------------------------------------------------------------
if(WIN32)
    set(GLM_INCLUDE_DIR "C:/libs/glm-1.0.3/glm")
else()
    set(GLM_INCLUDE_DIR "$ENV{HOME}/libs/glm-1.0.3")
endif()

# -----------------------------------------------------------------------------
# Set Path and Source for GLAD Loader
# -----------------------------------------------------------------------------
if(WIN32)
    set(GLAD_DIR "C:/libs/glad-0.1.36/opengl-3.3")
else()
    set(GLAD_DIR "$ENV{HOME}/libs/glad-0.1.36/opengl-3.3")
endif()

set(GLAD_INCLUDE_DIR "${GLAD_DIR}/include")
set(GLAD_SOURCE "${GLAD_DIR}/src/glad.c")

# -----------------------------------------------------------------------------
# Target Definition
# -----------------------------------------------------------------------------
set(PROJECT_SOURCES
    main.cpp
    ${GLAD_SOURCE}
)

add_executable(app ${PROJECT_SOURCES})

# Include GLM and GLAD headers
target_include_directories(app PRIVATE 
    ${GLM_INCLUDE_DIR}
    ${GLAD_INCLUDE_DIR}
)

# Link SDL3 statically and system OpenGL library
target_link_libraries(app PRIVATE SDL3::SDL3-static OpenGL::GL)

# -----------------------------------------------------------------------------
# Platform-Specific Compiler & Linker Flags
# -----------------------------------------------------------------------------
if(WIN32)
    target_compile_options(app PRIVATE -Os)
    target_link_options(app PRIVATE -static -s -static-libgcc)

    if(CMAKE_BUILD_TYPE STREQUAL "Debug")
        target_link_options(app PRIVATE -mconsole)
    else()
        target_link_options(app PRIVATE -mwindows)
    endif()
endif()

Step 3: Create Build & Execution Scripts Шаг 3: Создание скриптов сборки и запуска

Windows (MinGW / Batch Scripts)

config-exe.bat

cmake -G Ninja -S . -B dist/win

build-exe.bat

cmake --build dist/win

run-exe.bat

@echo off
.\dist\win\app.exe

Run the scripts sequentially in Command Prompt or PowerShell: Последовательно запустите скрипты в командной строке или PowerShell:

config-exe.bat
build-exe.bat
run-exe.bat

Ubuntu (Bash Scripts)

config-bin.sh

#!/usr/bin/env bash
set -e
cmake -G Ninja -S . -B dist/linux

build-bin.sh

#!/usr/bin/env bash
set -e
cmake --build dist/linux

run-bin.sh

#!/usr/bin/env bash
set -e
./dist/linux/app

Grant execute permissions on Ubuntu before running: Предоставьте права на выполнение в Ubuntu перед запуском:

chmod +x config-bin.sh build-bin.sh run-bin.sh
./config-bin.sh
./build-bin.sh
./run-bin.sh

Step 4: Expected Output Шаг 4: Ожидаемый результат

Upon running the application, GLAD initializes OpenGL 3.3 Core procedures and draws a smooth RGB-interpolated triangle: После запуска приложения GLAD инициализирует процедуры OpenGL 3.3 Core и отрисует треугольник с плавным RGB-градиентом:

SDL3 GLM GLAD OpenGL 3.3 Triangle (Classic)

or (if using the Callbacks API version): или (если используется версия с Callbacks API):

SDL3 GLM GLAD OpenGL 3.3 Triangle (Callbacks)