text_editor/src/platform/platform.cpp

#define BASIC_IMPL
#include "basic/basic.h"
#include "basic/filesystem.h"

#include "SDL3/SDL.h"
#include "external/glad/glad.h"
#include "external/stb_truetype.h"
#include "external/stb_truetype.c"

#include "basic/math_int.cpp"
#include "basic/math.cpp"
#include "font.cpp"
#include "render_opengl.cpp"

bool AppIsRunning  = true;
bool WaitForEvents = false;

int64_t FrameID;

void ProcessSDLEvent(SDL_Event *event) {
    switch (event->type) {
    case SDL_EVENT_QUIT: AppIsRunning = false; return;
    case SDL_EVENT_KEY_DOWN: {
        SDL_KeyboardEvent &key   = event->key;
        bool               shift = key.mod & SDL_KMOD_SHIFT;
        bool               ctrl  = key.mod & SDL_KMOD_CTRL;
        bool               alt   = key.mod & SDL_KMOD_ALT;
        bool               super = key.mod & SDL_KMOD_GUI;

        if (key.key == SDLK_F5) {
            AppIsRunning = false;
            return;
        }

    } break;
    case SDL_EVENT_KEY_UP: {
        SDL_KeyboardEvent &key   = event->key;
        bool               shift = key.mod & SDL_KMOD_SHIFT;
        bool               ctrl  = key.mod & SDL_KMOD_CTRL;
        bool               alt   = key.mod & SDL_KMOD_ALT;
        bool               super = key.mod & SDL_KMOD_GUI;

    } break;
    case SDL_EVENT_TEXT_INPUT: {
    } break;
    case SDL_EVENT_MOUSE_MOTION: {
    } break;
    case SDL_EVENT_MOUSE_BUTTON_DOWN: {
    } break;
    case SDL_EVENT_MOUSE_BUTTON_UP: {
    } break;
    case SDL_EVENT_MOUSE_WHEEL: {
    } break;
    }
}

void GLDebugCallback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar *message, const void *user) {
    printf("%s", message);
    if (severity == GL_DEBUG_SEVERITY_HIGH || severity == GL_DEBUG_SEVERITY_MEDIUM) {
        SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "OpenGL error", message, NULL);
    }
}

#if _WIN32
int WinMain(void *hInstance, void *hPrevInstance, const char *lpCmdLine, int nShowCmd)
#else
int main()
#endif
{
    InitScratch();
    if (SDL_Init(SDL_INIT_VIDEO) == -1) {
        SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't initialize SDL!", SDL_GetError(), NULL);
        return 1;
    }

    const char *glsl_version = "#version 450";
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 5);

    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
    SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
    Uint32      window_flags = SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN | SDL_WINDOW_HIGH_PIXEL_DENSITY;
    SDL_Window *window       = SDL_CreateWindow("Text editor", 1280, 720, window_flags);
    if (window == NULL) {
        SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't create window!", SDL_GetError(), NULL);
        return 1;
    }

    SDL_GLContext gl_context = SDL_GL_CreateContext(window);
    SDL_GL_MakeCurrent(window, gl_context);
    SDL_GL_SetSwapInterval(1); // Enable vsync
    SDL_ShowWindow(window);

    if (!gladLoadGLLoader((GLADloadproc)SDL_GL_GetProcAddress)) {
        SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't load opengl!", SDL_GetError(), NULL);
        return 1;
    }

    SDL_GL_SetSwapInterval(1); // vsync
    glDebugMessageCallback(&GLDebugCallback, NULL);
    glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);

    {
        Scratch scratch;
        Atlas   atlas = CreateAtlas(scratch, {1024, 1024});
        MainFont      = CreateFont(&atlas, 16, "C:\\Windows\\Fonts\\consola.ttf");
        {
            glCreateTextures(GL_TEXTURE_2D, 1, &atlas.texture_id);
            glTextureParameteri(atlas.texture_id, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
            glTextureParameteri(atlas.texture_id, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
            glTextureParameteri(atlas.texture_id, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
            glTextureParameteri(atlas.texture_id, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
            glTextureStorage2D(atlas.texture_id, 1, GL_R8, (GLsizei)atlas.size.x, (GLsizei)atlas.size.y);
            glTextureSubImage2D(atlas.texture_id, 0, 0, 0, (GLsizei)atlas.size.x, (GLsizei)atlas.size.y, GL_RED, GL_UNSIGNED_BYTE, atlas.bitmap);
        }
        MainFont.texture_id = atlas.texture_id;
    }

    InitRender();

    while (AppIsRunning) {
        FrameID += 1;
        int window_x, window_y;
        SDL_GetWindowSize(window, &window_x, &window_y);
        Vec2 window_size = {(float)window_x, (float)window_y};
        BeginFrameRender(window_size);

        SDL_Event event;
        if (WaitForEvents) {
            SDL_WaitEvent(&event);
            ProcessSDLEvent(&event);
        }
        while (SDL_PollEvent(&event)) {
            ProcessSDLEvent(&event);
        }

        {
            Scratch  scratch;
            uint64_t ms     = SDL_GetTicks();
            double   time   = (double)ms / 1000.0;
            String   string = Format(scratch, "%d %f %f", (int)FrameID, time, (time / (double)FrameID));
            DrawString(&MainFont, ToString16(scratch, string), {0, 0}, {255, 0, 0, 255});
        }
        EndFrameRender({0, 0, 0, 1});
        SDL_GL_SwapWindow(window);
    }

    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}