/**
  * @file lv_draw_sdl_arc.c
  *
  */
 
 /*********************
  *      INCLUDES
  *********************/
 #include "../../lv_conf_internal.h"
 
 #if LV_USE_GPU_SDL
 
 #include "lv_draw_sdl.h"
 #include "lv_draw_sdl_utils.h"
 #include "lv_draw_sdl_texture_cache.h"
 #include "lv_draw_sdl_composite.h"
 
 /*********************
  *      DEFINES
  *********************/
 
 /**********************
  *      TYPEDEFS
  **********************/
 
 /**********************
  *  STATIC PROTOTYPES
  **********************/
 
 /**********************
  *  STATIC VARIABLES
  **********************/
 
 /**********************
  *      MACROS
  **********************/
 
 static void dump_masks(SDL_Texture * texture, const lv_area_t * coords, const int16_t * ids, int16_t ids_count,
                        const int16_t * caps);
 
 static void get_cap_area(int16_t angle, lv_coord_t thickness, uint16_t radius, const lv_point_t * center,
                          lv_area_t * out);
 
 /**********************
  *   GLOBAL FUNCTIONS
  **********************/
 void lv_draw_sdl_draw_arc(lv_draw_ctx_t * draw_ctx, const lv_draw_arc_dsc_t * dsc, const lv_point_t * center,
                           uint16_t radius, uint16_t start_angle, uint16_t end_angle)
 {
     lv_draw_sdl_ctx_t * ctx = (lv_draw_sdl_ctx_t *) draw_ctx;
 
     lv_area_t area_out;
     area_out.x1 = center->x - radius;
     area_out.y1 = center->y - radius;
     area_out.x2 = center->x + radius - 1;  /*-1 because the center already belongs to the left/bottom part*/
     area_out.y2 = center->y + radius - 1;
 
     lv_area_t draw_area;
     if(!_lv_area_intersect(&draw_area, &area_out, draw_ctx->clip_area)) {
         return;
     }
 
     lv_area_t area_in;
     lv_area_copy(&area_in, &area_out);
     area_in.x1 += dsc->width;
     area_in.y1 += dsc->width;
     area_in.x2 -= dsc->width;
     area_in.y2 -= dsc->width;
 
 
     while(start_angle >= 360) start_angle -= 360;
     while(end_angle >= 360) end_angle -= 360;
 
     int16_t mask_ids[3] = {LV_MASK_ID_INV, LV_MASK_ID_INV, LV_MASK_ID_INV}, mask_ids_count = 1;
     int16_t cap_ids[2] = {LV_MASK_ID_INV, LV_MASK_ID_INV};
 
     lv_draw_mask_radius_param_t mask_out_param;
     lv_draw_mask_radius_init(&mask_out_param, &area_out, LV_RADIUS_CIRCLE, false);
     mask_ids[0] = lv_draw_mask_add(&mask_out_param, NULL);
 
     lv_draw_mask_radius_param_t mask_in_param;
     if(lv_area_get_width(&area_in) > 0 && lv_area_get_height(&area_in) > 0) {
         lv_draw_mask_radius_init(&mask_in_param, &area_in, LV_RADIUS_CIRCLE, true);
         mask_ids[1] = lv_draw_mask_add(&mask_in_param, NULL);
         mask_ids_count++;
     }
 
     lv_draw_mask_angle_param_t mask_angle_param;
     if((start_angle - end_angle) % 360) {
         lv_draw_mask_angle_init(&mask_angle_param, center->x, center->y, start_angle, end_angle);
         mask_ids[2] = lv_draw_mask_add(&mask_angle_param, NULL);
         mask_ids_count++;
     }
 
     lv_draw_mask_radius_param_t cap_start_param, cap_end_param;
     if(mask_ids_count == 3 && dsc->rounded) {
         lv_area_t start_area, end_area;
         get_cap_area((int16_t) start_angle, dsc->width, radius, center, &start_area);
         get_cap_area((int16_t) end_angle, dsc->width, radius, center, &end_area);
         lv_draw_mask_radius_init(&cap_start_param, &start_area, dsc->width / 2, false);
         cap_ids[0] = lv_draw_mask_add(&cap_start_param, NULL);
         lv_draw_mask_radius_init(&cap_end_param, &end_area, dsc->width / 2, false);
         cap_ids[1] = lv_draw_mask_add(&cap_end_param, NULL);
     }
 
     lv_coord_t w = lv_area_get_width(&draw_area), h = lv_area_get_height(&draw_area);
     SDL_Texture * texture = lv_draw_sdl_composite_texture_obtain(ctx, LV_DRAW_SDL_COMPOSITE_TEXTURE_ID_STREAM1, w, h);
     SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
     dump_masks(texture, &draw_area, mask_ids, mask_ids_count, cap_ids[0] != LV_MASK_ID_INV ? cap_ids : NULL);
 
     lv_draw_mask_remove_id(mask_ids[0]);
     lv_draw_mask_free_param(&mask_out_param);
 
     if(mask_ids_count > 1) {
         lv_draw_mask_remove_id(mask_ids[1]);
         lv_draw_mask_free_param(&mask_in_param);
     }
 
     if(mask_ids_count > 2) {
         lv_draw_mask_remove_id(mask_ids[2]);
         lv_draw_mask_free_param(&mask_angle_param);
     }
 
     if(cap_ids[0] != LV_MASK_ID_INV) {
         lv_draw_mask_remove_id(cap_ids[0]);
         lv_draw_mask_remove_id(cap_ids[1]);
         lv_draw_mask_free_param(&cap_start_param);
         lv_draw_mask_free_param(&cap_end_param);
     }
 
     SDL_Rect srcrect = {0, 0, w, h}, dstrect;
     lv_area_to_sdl_rect(&draw_area, &dstrect);
     SDL_Color color;
     lv_color_to_sdl_color(&dsc->color, &color);
     SDL_SetTextureColorMod(texture, color.r, color.g, color.b);
     SDL_SetTextureAlphaMod(texture, dsc->opa);
     SDL_RenderCopy(ctx->renderer, texture, &srcrect, &dstrect);
 }
 
 /**********************
  *   STATIC FUNCTIONS
  **********************/
 
 static void dump_masks(SDL_Texture * texture, const lv_area_t * coords, const int16_t * ids, int16_t ids_count,
                        const int16_t * caps)
 {
     lv_coord_t w = lv_area_get_width(coords), h = lv_area_get_height(coords);
     SDL_assert(w > 0 && h > 0);
     SDL_Rect rect = {0, 0, w, h};
     uint8_t * pixels;
     int pitch;
     if(SDL_LockTexture(texture, &rect, (void **) &pixels, &pitch) != 0) return;
 
     lv_opa_t * line_buf = lv_mem_buf_get(rect.w);
     for(lv_coord_t y = 0; y < rect.h; y++) {
         lv_memset_ff(line_buf, rect.w);
         lv_coord_t abs_x = (lv_coord_t) coords->x1, abs_y = (lv_coord_t)(y + coords->y1), len = (lv_coord_t) rect.w;
         lv_draw_mask_res_t res;
         res = lv_draw_mask_apply_ids(line_buf, abs_x, abs_y, len, ids, ids_count);
         if(res == LV_DRAW_MASK_RES_TRANSP) {
             lv_memset_00(&pixels[y * pitch], 4 * rect.w);
         }
         else if(res == LV_DRAW_MASK_RES_FULL_COVER) {
             lv_memset_ff(&pixels[y * pitch], 4 * rect.w);
         }
         else {
             for(int x = 0; x < rect.w; x++) {
                 uint8_t * pixel = &pixels[y * pitch + x * 4];
                 *pixel = line_buf[x];
                 pixel[1] = pixel[2] = pixel[3] = 0xFF;
             }
         }
         if(caps) {
             for(int i = 0; i < 2; i++) {
                 lv_memset_ff(line_buf, rect.w);
                 res = lv_draw_mask_apply_ids(line_buf, abs_x, abs_y, len, &caps[i], 1);
                 if(res == LV_DRAW_MASK_RES_TRANSP) {
                     /* Ignore */
                 }
                 else if(res == LV_DRAW_MASK_RES_FULL_COVER) {
                     lv_memset_ff(&pixels[y * pitch], 4 * rect.w);
                 }
                 else {
                     for(int x = 0; x < rect.w; x++) {
                         uint8_t * pixel = &pixels[y * pitch + x * 4];
                         uint16_t old_opa = line_buf[x] + *pixel;
                         *pixel = LV_MIN(old_opa, 0xFF);
                         pixel[1] = pixel[2] = pixel[3] = 0xFF;
                     }
                 }
             }
         }
     }
     lv_mem_buf_release(line_buf);
     SDL_UnlockTexture(texture);
 }
 
 static void get_cap_area(int16_t angle, lv_coord_t thickness, uint16_t radius, const lv_point_t * center,
                          lv_area_t * out)
 {
     const uint8_t ps = 8;
     const uint8_t pa = 127;
 
     int32_t thick_half = thickness / 2;
     uint8_t thick_corr = (thickness & 0x01) ? 0 : 1;
 
     int32_t cir_x;
     int32_t cir_y;
 
     cir_x = ((radius - thick_half) * lv_trigo_sin((int16_t)(90 - angle))) >> (LV_TRIGO_SHIFT - ps);
     cir_y = ((radius - thick_half) * lv_trigo_sin(angle)) >> (LV_TRIGO_SHIFT - ps);
 
     /*Actually the center of the pixel need to be calculated so apply 1/2 px offset*/
     if(cir_x > 0) {
         cir_x = (cir_x - pa) >> ps;
         out->x1 = cir_x - thick_half + thick_corr;
         out->x2 = cir_x + thick_half;
     }
     else {
         cir_x = (cir_x + pa) >> ps;
         out->x1 = cir_x - thick_half;
         out->x2 = cir_x + thick_half - thick_corr;
     }
 
     if(cir_y > 0) {
         cir_y = (cir_y - pa) >> ps;
         out->y1 = cir_y - thick_half + thick_corr;
         out->y2 = cir_y + thick_half;
     }
     else {
         cir_y = (cir_y + pa) >> ps;
         out->y1 = cir_y - thick_half;
         out->y2 = cir_y + thick_half - thick_corr;
     }
     lv_area_move(out, center->x, center->y);
 }
 
 #endif /*LV_USE_GPU_SDL*/

© 2023 acidvegas, inc • generated with stagit