clay/examples/SDL3-simple-demo/main.c

#define SDL_MAIN_USE_CALLBACKS
#include <SDL3/SDL_main.h>
#include <SDL3/SDL.h>
#include <SDL3_ttf/SDL_ttf.h>

#define CLAY_IMPLEMENTATION
#include "../../clay.h"

#include <stdio.h>

#include "../../renderers/SDL3/clay_renderer_SDL3.c"
#include "../shared-layouts/clay-video-demo.c"

static const Uint32 FONT_ID = 0;

static const Clay_Color COLOR_ORANGE    = (Clay_Color) {225, 138, 50, 255};
static const Clay_Color COLOR_BLUE      = (Clay_Color) {111, 173, 162, 255};
static const Clay_Color COLOR_LIGHT     = (Clay_Color) {224, 215, 210, 255};

typedef struct app_state {
    SDL_Window *window;
    Clay_SDL3RendererData rendererData;
    ClayVideoDemo_Data demoData;
} AppState;

SDL_Texture *sample_image;
bool show_demo = true;

static inline Clay_Dimensions SDL_MeasureText(Clay_StringSlice text, Clay_TextElementConfig *config, void *userData)
{
    TTF_Font **fonts = userData;
    TTF_Font *font = fonts[config->fontId];
    int width, height;

    TTF_SetFontSize(font, config->fontSize);
    if (!TTF_GetStringSize(font, text.chars, text.length, &width, &height)) {
        SDL_LogError(SDL_LOG_CATEGORY_ERROR, "Failed to measure text: %s", SDL_GetError());
    }

    return (Clay_Dimensions) { (float) width, (float) height };
}

void HandleClayErrors(Clay_ErrorData errorData) {
    printf("%s", errorData.errorText.chars);
}


Clay_RenderCommandArray ClayImageSample_CreateLayout() {
    Clay_BeginLayout();

    Clay_Sizing layoutExpand = {
        .width = CLAY_SIZING_GROW(0),
        .height = CLAY_SIZING_GROW(0)
    };

    CLAY(CLAY_ID("OuterContainer"), {
        .layout = {
            .layoutDirection = CLAY_TOP_TO_BOTTOM,
            .sizing = layoutExpand,
            .padding = CLAY_PADDING_ALL(16),
            .childGap = 16
        }
    }) {
        CLAY(CLAY_ID("SampleImage"), {
            .layout = {
                .sizing = layoutExpand
            },
            .aspectRatio = { 23.0 / 42.0 },
            .image = {
                .imageData = sample_image,
            }
        });
    }

    return Clay_EndLayout();
}


SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[])
{
    (void) argc;
    (void) argv;

    if (!TTF_Init()) {
        return SDL_APP_FAILURE;
    }

    AppState *state = SDL_calloc(1, sizeof(AppState));
    if (!state) {
        return SDL_APP_FAILURE;
    }
    *appstate = state;

    if (!SDL_CreateWindowAndRenderer("Clay Demo", 640, 480, 0, &state->window, &state->rendererData.renderer)) {
        SDL_LogError(SDL_LOG_CATEGORY_ERROR, "Failed to create window and renderer: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }
    SDL_SetWindowResizable(state->window, true);

    state->rendererData.textEngine = TTF_CreateRendererTextEngine(state->rendererData.renderer);
    if (!state->rendererData.textEngine) {
        SDL_LogError(SDL_LOG_CATEGORY_ERROR, "Failed to create text engine from renderer: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }

    state->rendererData.fonts = SDL_calloc(1, sizeof(TTF_Font *));
    if (!state->rendererData.fonts) {
        SDL_LogError(SDL_LOG_CATEGORY_ERROR, "Failed to allocate memory for the font array: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }

    TTF_Font *font = TTF_OpenFont("resources/Roboto-Regular.ttf", 24);
    if (!font) {
        SDL_LogError(SDL_LOG_CATEGORY_ERROR, "Failed to load font: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }

    state->rendererData.fonts[FONT_ID] = font;

    sample_image = IMG_LoadTexture(state->rendererData.renderer, "resources/sample.png");
    if (!sample_image) {
        SDL_LogError(SDL_LOG_CATEGORY_ERROR, "Failed to load image: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }

    /* Initialize Clay */
    uint64_t totalMemorySize = Clay_MinMemorySize();
    Clay_Arena clayMemory = (Clay_Arena) {
        .memory = SDL_malloc(totalMemorySize),
        .capacity = totalMemorySize
    };

    int width, height;
    SDL_GetWindowSize(state->window, &width, &height);
    Clay_Initialize(clayMemory, (Clay_Dimensions) { (float) width, (float) height }, (Clay_ErrorHandler) { HandleClayErrors });
    Clay_SetMeasureTextFunction(SDL_MeasureText, state->rendererData.fonts);

    state->demoData = ClayVideoDemo_Initialize();

    *appstate = state;
    return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event)
{
    SDL_AppResult ret_val = SDL_APP_CONTINUE;

    switch (event->type) {
        case SDL_EVENT_QUIT:
            ret_val = SDL_APP_SUCCESS;
            break;
        case SDL_EVENT_KEY_UP:
            if (event->key.scancode == SDL_SCANCODE_SPACE) {
                show_demo = !show_demo;
            }
            break;
        case SDL_EVENT_WINDOW_RESIZED:
            Clay_SetLayoutDimensions((Clay_Dimensions) { (float) event->window.data1, (float) event->window.data2 });
            break;
        case SDL_EVENT_MOUSE_MOTION:
            Clay_SetPointerState((Clay_Vector2) { event->motion.x, event->motion.y },
                                 event->motion.state & SDL_BUTTON_LMASK);
            break;
        case SDL_EVENT_MOUSE_BUTTON_DOWN:
            Clay_SetPointerState((Clay_Vector2) { event->button.x, event->button.y },
                                 event->button.button == SDL_BUTTON_LEFT);
            break;
        case SDL_EVENT_MOUSE_WHEEL:
            Clay_UpdateScrollContainers(true, (Clay_Vector2) { event->wheel.x, event->wheel.y }, 0.01f);
            break;
        default:
            break;
    };

    return ret_val;
}

SDL_AppResult SDL_AppIterate(void *appstate)
{
    AppState *state = appstate;

    Clay_RenderCommandArray render_commands = (show_demo
        ? ClayVideoDemo_CreateLayout(&state->demoData)
        : ClayImageSample_CreateLayout()
    );

    SDL_SetRenderDrawColor(state->rendererData.renderer, 0, 0, 0, 255);
    SDL_RenderClear(state->rendererData.renderer);

    SDL_Clay_RenderClayCommands(&state->rendererData, &render_commands);

    SDL_RenderPresent(state->rendererData.renderer);

    return SDL_APP_CONTINUE;
}

void SDL_AppQuit(void *appstate, SDL_AppResult result)
{
    (void) result;

    if (result != SDL_APP_SUCCESS) {
        SDL_LogError(SDL_LOG_CATEGORY_ERROR, "Application failed to run");
    }

    AppState *state = appstate;

    if (sample_image) {
        SDL_DestroyTexture(sample_image);
    }

    if (state) {
        if (state->rendererData.renderer)
            SDL_DestroyRenderer(state->rendererData.renderer);

        if (state->window)
            SDL_DestroyWindow(state->window);

        if (state->rendererData.fonts) {
            for(size_t i = 0; i < sizeof(state->rendererData.fonts) / sizeof(*state->rendererData.fonts); i++) {
                TTF_CloseFont(state->rendererData.fonts[i]);
            }

            SDL_free(state->rendererData.fonts);
        }

        if (state->rendererData.textEngine)
            TTF_DestroyRendererTextEngine(state->rendererData.textEngine);

        SDL_free(state);
    }
    TTF_Quit();
}