Add minimal SDL2 example

CMakeLists.txt

@@ -9,4 +9,5 @@ if(NOT MSVC)
   add_subdirectory("examples/cairo-pdf-rendering")
   add_subdirectory("examples/clay-official-website")
   add_subdirectory("examples/introducing-clay-video-demo")
+  add_subdirectory("examples/minimal-sdl2")
 endif()

examples/minimal-sdl2/CMakeLists.txt

@@ -0,0 +1,43 @@
+cmake_minimum_required(VERSION 3.27)
+project(minimal_sdl2 C)
+set(CMAKE_C_STANDARD 99)
+
+include(FetchContent)
+set(FETCHCONTENT_QUIET FALSE)
+
+FetchContent_Declare(
+    SDL2
+    GIT_REPOSITORY "https://github.com/libsdl-org/SDL.git"
+    GIT_TAG "release-2.30.10"
+    GIT_PROGRESS TRUE
+    GIT_SHALLOW TRUE
+)
+FetchContent_MakeAvailable(SDL2)
+
+FetchContent_Declare(
+    SDL2_ttf
+    GIT_REPOSITORY "https://github.com/libsdl-org/SDL_ttf.git"
+    GIT_TAG "release-2.22.0"
+    GIT_PROGRESS TRUE
+    GIT_SHALLOW TRUE
+)
+FetchContent_MakeAvailable(SDL2_ttf)
+
+add_executable(minimal_sdl2 main.c)
+
+target_compile_options(minimal_sdl2 PUBLIC)
+target_include_directories(minimal_sdl2 PUBLIC .)
+
+target_link_libraries(minimal_sdl2 PUBLIC
+    SDL2::SDL2main
+    SDL2::SDL2-static
+    SDL2_ttf::SDL2_ttf-static
+)
+set(CMAKE_CXX_FLAGS_DEBUG "-Wall -Werror -DCLAY_DEBUG")
+set(CMAKE_CXX_FLAGS_RELEASE "-O3")
+
+add_custom_command(
+        TARGET minimal_sdl2 POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E copy_directory
+        ${CMAKE_CURRENT_SOURCE_DIR}/resources
+        ${CMAKE_CURRENT_BINARY_DIR}/resources)

examples/minimal-sdl2/main.c

@@ -0,0 +1,220 @@
+#define CLAY_IMPLEMENTATION
+#include "../../clay.h"
+
+#include <SDL.h>
+#include <SDL_ttf.h>
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+
+static const uint32_t FONT_ID_BODY_24 = 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};
+
+
+static void Label(Clay_String text) {
+    CLAY(CLAY_LAYOUT({ .padding = {16, 8} }),
+        CLAY_RECTANGLE({ .color = Clay_Hovered() ? COLOR_BLUE : COLOR_ORANGE })
+    ) {
+        CLAY_TEXT(text, CLAY_TEXT_CONFIG({
+            .textColor = { 255, 255, 255, 255 },
+            .fontId = FONT_ID_BODY_24,
+            .fontSize = 24,
+        }));
+    }
+}
+
+
+static Clay_RenderCommandArray CreateLayout() {
+    Clay_BeginLayout();
+    CLAY(CLAY_ID("MainContent"),
+        CLAY_LAYOUT({
+            .sizing = {
+                .width = CLAY_SIZING_GROW(),
+                .height = CLAY_SIZING_GROW(),
+            },
+            .childAlignment = {
+                .x = CLAY_ALIGN_X_CENTER,
+                .y = CLAY_ALIGN_Y_CENTER,
+            }
+        }), 
+        CLAY_RECTANGLE({
+            .color = COLOR_LIGHT,
+        })
+    ) {
+        Label(CLAY_STRING("Hello, World!"));
+    }
+    return Clay_EndLayout();
+}
+
+
+typedef struct
+{
+    uint32_t fontId;
+    TTF_Font *font;
+} Font;
+static Font fonts[1];
+
+
+static Clay_Dimensions MeasureText(Clay_String *text, Clay_TextElementConfig *config);
+static void Render(SDL_Renderer *renderer, Clay_RenderCommandArray renderCommands);
+
+
+int main(void) {
+    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+        fprintf(stderr, "Error: could not initialize SDL: %s\n", SDL_GetError());
+        return 1;
+    }
+    if (TTF_Init() < 0) {
+        fprintf(stderr, "Error: could not initialize TTF: %s\n", TTF_GetError());
+        return 1;
+    }
+
+    TTF_Font *font = TTF_OpenFont("resources/Roboto-Regular.ttf", 24);
+    if (!font) {
+        fprintf(stderr, "Error: could not load font: %s\n", TTF_GetError());
+        return 1;
+    }
+    fonts[FONT_ID_BODY_24] = (Font) {
+        .fontId = FONT_ID_BODY_24,
+        .font = font,
+    };
+
+    SDL_Window *window = NULL;
+    SDL_Renderer *renderer = NULL;
+    if (SDL_CreateWindowAndRenderer(800, 600, SDL_WINDOW_RESIZABLE, &window, &renderer) < 0) {
+        fprintf(stderr, "Error: could not create window and renderer: %s", SDL_GetError());
+    }
+
+    uint64_t totalMemorySize = Clay_MinMemorySize();
+    Clay_Arena clayMemory = (Clay_Arena) {
+        .label = CLAY_STRING("Clay Memory Arena"),
+        .capacity = totalMemorySize,
+        .memory = (char *)malloc(totalMemorySize),
+    };
+
+    Clay_SetMeasureTextFunction(MeasureText);
+
+    int windowWidth = 0;
+    int windowHeight = 0;
+    SDL_GetWindowSize(window, &windowWidth, &windowHeight);
+    Clay_Initialize(clayMemory, (Clay_Dimensions) { (float)windowWidth, (float)windowHeight });
+
+    while (true) {
+        SDL_Event event;
+        while (SDL_PollEvent(&event)) {
+            switch (event.type) {
+            case SDL_QUIT: goto quit;
+            }
+        }
+        int mouseX = 0;
+        int mouseY = 0;
+        Uint32 mouseState = SDL_GetMouseState(&mouseX, &mouseY);
+        Clay_Vector2 mousePosition = (Clay_Vector2){ (float)mouseX, (float)mouseY };
+        Clay_SetPointerState(mousePosition, mouseState & SDL_BUTTON(1));
+        
+        SDL_GetWindowSize(window, &windowWidth, &windowHeight);
+        Clay_SetLayoutDimensions((Clay_Dimensions) { (float)windowWidth, (float)windowHeight });
+
+        Clay_RenderCommandArray renderCommands = CreateLayout();
+        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+        SDL_RenderClear(renderer);
+
+        Render(renderer, renderCommands);
+
+        SDL_RenderPresent(renderer);
+    }
+quit:
+
+    SDL_DestroyRenderer(renderer);
+    SDL_DestroyWindow(window);
+    TTF_Quit();
+    SDL_Quit();
+    return 0;
+}
+
+
+static Clay_Dimensions MeasureText(Clay_String *text, Clay_TextElementConfig *config)
+{
+    TTF_Font *font = fonts[config->fontId].font;
+    char *chars = (char *)calloc(text->length + 1, 1);
+    memcpy(chars, text->chars, text->length);
+    int width = 0;
+    int height = 0;
+    if (TTF_SizeUTF8(font, chars, &width, &height) < 0) {
+        fprintf(stderr, "Error: could not measure text: %s\n", TTF_GetError());
+        #ifdef CLAY_OVERFLOW_TRAP
+        raise(SIGTRAP);
+        #endif
+        exit(1);
+    }
+    free(chars);
+    return (Clay_Dimensions) {
+        .width = (float)width,
+        .height = (float)height,
+    };
+}
+
+
+static void Render(SDL_Renderer *renderer, Clay_RenderCommandArray renderCommands)
+{
+    for (uint32_t i = 0; i < renderCommands.length; i++)
+    {
+        Clay_RenderCommand *renderCommand = Clay_RenderCommandArray_Get(&renderCommands, i);
+        Clay_BoundingBox boundingBox = renderCommand->boundingBox;
+        switch (renderCommand->commandType)
+        {
+            case CLAY_RENDER_COMMAND_TYPE_RECTANGLE: {
+                Clay_RectangleElementConfig *config = renderCommand->config.rectangleElementConfig;
+                Clay_Color color = config->color;
+                SDL_SetRenderDrawColor(renderer, color.r, color.g, color.b, color.a);
+                SDL_FRect rect = (SDL_FRect) {
+                    .x = boundingBox.x,
+                    .y = boundingBox.y,
+                    .w = boundingBox.width,
+                    .h = boundingBox.height,
+                };
+                SDL_RenderFillRectF(renderer, &rect);
+                break;
+            }
+            case CLAY_RENDER_COMMAND_TYPE_TEXT: {
+                Clay_TextElementConfig *config = renderCommand->config.textElementConfig;
+                Clay_String text = renderCommand->text;
+                char *cloned = (char *)calloc(text.length + 1, 1);
+                memcpy(cloned, text.chars, text.length);
+                TTF_Font* font = fonts[config->fontId].font;
+                SDL_Surface *surface = TTF_RenderUTF8_Blended(font, cloned, (SDL_Color) {
+                    .r = (Uint8)config->textColor.r,
+                    .g = (Uint8)config->textColor.g,
+                    .b = (Uint8)config->textColor.b,
+                    .a = (Uint8)config->textColor.a,
+                });
+                SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, surface);
+
+                SDL_Rect destination = (SDL_Rect){
+                    .x = (Uint8)boundingBox.x,
+                    .y = (Uint8)boundingBox.y,
+                    .w = (Uint8)boundingBox.width,
+                    .h = (Uint8)boundingBox.height,
+                };
+                SDL_RenderCopy(renderer, texture, NULL, &destination);
+
+                SDL_DestroyTexture(texture);
+                SDL_FreeSurface(surface);
+                free(cloned);
+                break;
+            }
+            default: {
+                fprintf(stderr, "Error: unhandled render command: %d\n", renderCommand->commandType);
+                #ifdef CLAY_OVERFLOW_TRAP
+                raise(SIGTRAP);
+                #endif
+                exit(1);
+            }
+        }
+    }
+}