arch(draw): allow replacing the draw engine

BREAKING CHANGE: the API of lv_draw_... function have been changed

src/draw/sdl/lv_draw_sdl.h

@@ -0,0 +1,94 @@
+/**
+ * @file lv_draw_sdl.h
+ *
+ */
+
+#ifndef LV_DRAW_SDL_H
+#define LV_DRAW_SDL_H
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*********************
+ *      INCLUDES
+ *********************/
+#include "../../lv_conf_internal.h"
+
+#if LV_USE_GPU_SDL
+
+#include LV_GPU_SDL_INCLUDE_PATH
+
+#include "../sw/lv_draw_sw.h"
+
+/*********************
+ *      DEFINES
+ *********************/
+
+#if SDL_BYTEORDER == SDL_BIG_ENDIAN
+#define LV_DRAW_SDL_TEXTURE_FORMAT SDL_PIXELFORMAT_ARGB8888
+#else
+#define LV_DRAW_SDL_TEXTURE_FORMAT SDL_PIXELFORMAT_RGBA8888
+#endif
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+
+struct lv_draw_sdl_context_internals_t;
+
+typedef struct {
+    /**
+     * Render for display driver
+     */
+    SDL_Renderer * renderer;
+} lv_draw_sdl_drv_param_t;
+
+typedef struct {
+    lv_draw_sw_ctx_t base_draw;
+    SDL_Renderer * renderer;
+    struct lv_draw_sdl_context_internals_t * internals;
+} lv_draw_sdl_ctx_t;
+
+/**********************
+ * GLOBAL PROTOTYPES
+ **********************/
+
+void lv_draw_sdl_init_ctx(lv_disp_drv_t * disp_drv, lv_draw_ctx_t * draw_ctx);
+
+/**
+ * @brief Free caches
+ *
+ */
+void lv_draw_sdl_deinit_ctx(lv_disp_drv_t * disp_drv, lv_draw_ctx_t * draw_ctx);
+
+SDL_Texture * lv_draw_sdl_create_screen_texture(SDL_Renderer * renderer, lv_coord_t hor, lv_coord_t ver);
+
+/*======================
+ * Add/remove functions
+ *=====================*/
+
+/*=====================
+ * Setter functions
+ *====================*/
+
+/*=====================
+ * Getter functions
+ *====================*/
+
+/*=====================
+ * Other functions
+ *====================*/
+
+/**********************
+ *      MACROS
+ **********************/
+
+#endif /*LV_USE_GPU_SDL*/
+
+#ifdef __cplusplus
+} /*extern "C"*/
+#endif
+
+#endif /*LV_DRAW_SDL_H*/