/*

   Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>

   This software is provided 'as-is', without any express or implied

   warranty.  In no event will the authors be held liable for any damages

   arising from the use of this software.

   Permission is granted to anyone to use this software for any purpose,

   including commercial applications, and to alter it and redistribute it

   freely.

 */

 /* Simple program:  draw as many random objects on the screen as possible */

 #include <stdlib.h>

 #include <stdio.h>

 #include <time.h>

 #ifdef __EMSCRIPTEN__

 #include <emscripten/emscripten.h>

 #endif

 #include "SDL_test_common.h"

 #define SWAP(typ,a,b) do{typ t=a;a=b;b=t;}while(0)

 #define NUM_OBJECTS 100

 static SDLTest_CommonState *state;

 static int num_objects;

 static SDL_bool cycle_color;

 static SDL_bool cycle_alpha;

 static int cycle_direction = 1;

 static int current_alpha = 255;

 static int current_color = 255;

 static SDL_BlendMode blendMode = SDL_BLENDMODE_NONE;

 int mouse_begin_x = -1, mouse_begin_y = -1;

 int done;

 void

 DrawPoints(SDL_Renderer * renderer)

 {

     int i;

     int x, y;

     SDL_Rect viewport;

     /* Query the sizes */

     SDL_RenderGetViewport(renderer, &viewport);

     for (i = 0; i < num_objects * 4; ++i) {

         /* Cycle the color and alpha, if desired */

         if (cycle_color) {

             current_color += cycle_direction;

             if (current_color < 0) {

                 current_color = 0;

                 cycle_direction = -cycle_direction;

             }

             if (current_color > 255) {

                 current_color = 255;

                 cycle_direction = -cycle_direction;

             }

         }

         if (cycle_alpha) {

             current_alpha += cycle_direction;

             if (current_alpha < 0) {

                 current_alpha = 0;

                 cycle_direction = -cycle_direction;

             }

             if (current_alpha > 255) {

                 current_alpha = 255;

                 cycle_direction = -cycle_direction;

             }

         }

         SDL_SetRenderDrawColor(renderer, 255, (Uint8) current_color,

                                (Uint8) current_color, (Uint8) current_alpha);

         x = rand() % viewport.w;

         y = rand() % viewport.h;

         SDL_RenderDrawPoint(renderer, x, y);

     }

 }

 #define MAX_LINES 16

 int num_lines = 0;

 SDL_Rect lines[MAX_LINES];

 static int

 add_line(int x1, int y1, int x2, int y2)

 {

     if (num_lines >= MAX_LINES)

         return 0;

     if ((x1 == x2) && (y1 == y2))

         return 0;

     SDL_Log("adding line (%d, %d), (%d, %d)\n", x1, y1, x2, y2);

     lines[num_lines].x = x1;

     lines[num_lines].y = y1;

     lines[num_lines].w = x2;

     lines[num_lines].h = y2;

     return ++num_lines;

 }

 void

 DrawLines(SDL_Renderer * renderer)

 {

     int i;

     SDL_Rect viewport;

     /* Query the sizes */

     SDL_RenderGetViewport(renderer, &viewport);

     SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);

     for (i = 0; i < num_lines; ++i) {

         if (i == -1) {

             SDL_RenderDrawLine(renderer, 0, 0, viewport.w - 1, viewport.h - 1);

             SDL_RenderDrawLine(renderer, 0, viewport.h - 1, viewport.w - 1, 0);

             SDL_RenderDrawLine(renderer, 0, viewport.h / 2, viewport.w - 1, viewport.h / 2);

             SDL_RenderDrawLine(renderer, viewport.w / 2, 0, viewport.w / 2, viewport.h - 1);

         } else {

             SDL_RenderDrawLine(renderer, lines[i].x, lines[i].y, lines[i].w, lines[i].h);

         }

     }

 }

 #define MAX_RECTS 16

 int num_rects = 0;

 SDL_Rect rects[MAX_RECTS];

 static int

 add_rect(int x1, int y1, int x2, int y2)

 {

     if (num_rects >= MAX_RECTS)

         return 0;

     if ((x1 == x2) || (y1 == y2))

         return 0;

     if (x1 > x2)

         SWAP(int, x1, x2);

     if (y1 > y2)

         SWAP(int, y1, y2);

     SDL_Log("adding rect (%d, %d), (%d, %d) [%dx%d]\n", x1, y1, x2, y2,

            x2 - x1, y2 - y1);

     rects[num_rects].x = x1;

     rects[num_rects].y = y1;

     rects[num_rects].w = x2 - x1;

     rects[num_rects].h = y2 - y1;

     return ++num_rects;

 }

 static void

 DrawRects(SDL_Renderer * renderer)

 {

     SDL_SetRenderDrawColor(renderer, 255, 127, 0, 255);

     SDL_RenderFillRects(renderer, rects, num_rects);

 }

 static void

 DrawRectLineIntersections(SDL_Renderer * renderer)

 {

     int i, j;

     SDL_SetRenderDrawColor(renderer, 0, 255, 55, 255);

     for (i = 0; i < num_rects; i++)

         for (j = 0; j < num_lines; j++) {

             int x1, y1, x2, y2;

             SDL_Rect r;

             r = rects[i];

             x1 = lines[j].x;

             y1 = lines[j].y;

             x2 = lines[j].w;

             y2 = lines[j].h;

             if (SDL_IntersectRectAndLine(&r, &x1, &y1, &x2, &y2)) {

                 SDL_RenderDrawLine(renderer, x1, y1, x2, y2);

             }

         }

 }

 static void

 DrawRectRectIntersections(SDL_Renderer * renderer)

 {

     int i, j;

     SDL_SetRenderDrawColor(renderer, 255, 200, 0, 255);

     for (i = 0; i < num_rects; i++)

         for (j = i + 1; j < num_rects; j++) {

             SDL_Rect r;

             if (SDL_IntersectRect(&rects[i], &rects[j], &r)) {

                 SDL_RenderFillRect(renderer, &r);

             }

         }

 }

 void

 loop()

 {

     int i;

     SDL_Event event;

     /* Check for events */

     while (SDL_PollEvent(&event)) {

         SDLTest_CommonEvent(state, &event, &done);

         switch (event.type) {

         case SDL_MOUSEBUTTONDOWN:

             mouse_begin_x = event.button.x;

             mouse_begin_y = event.button.y;

             break;

         case SDL_MOUSEBUTTONUP:

             if (event.button.button == 3)

                 add_line(mouse_begin_x, mouse_begin_y, event.button.x,

                          event.button.y);

             if (event.button.button == 1)

                 add_rect(mouse_begin_x, mouse_begin_y, event.button.x,

                          event.button.y);

             break;

         case SDL_KEYDOWN:

             switch (event.key.keysym.sym) {

             case 'l':

                 if (event.key.keysym.mod & KMOD_SHIFT)

                     num_lines = 0;

                 else

                     add_line(rand() % 640, rand() % 480, rand() % 640,

                              rand() % 480);

                 break;

             case 'r':

                 if (event.key.keysym.mod & KMOD_SHIFT)

                     num_rects = 0;

                 else

                     add_rect(rand() % 640, rand() % 480, rand() % 640,

                              rand() % 480);

                 break;

             }

             break;

         default:

             break;

         }

     }

     for (i = 0; i < state->num_windows; ++i) {

         SDL_Renderer *renderer = state->renderers[i];

         if (state->windows[i] == NULL)

             continue;

         SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF);

         SDL_RenderClear(renderer);

         DrawRects(renderer);

         DrawPoints(renderer);

         DrawRectRectIntersections(renderer);

         DrawLines(renderer);

         DrawRectLineIntersections(renderer);

         SDL_RenderPresent(renderer);

     }

 #ifdef __EMSCRIPTEN__

     if (done) {

         emscripten_cancel_main_loop();

     }

 #endif

 }

 int

 main(int argc, char *argv[])

 {

     int i;

     Uint32 then, now, frames;

     /* Enable standard application logging */

     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);

     /* Initialize parameters */

     num_objects = NUM_OBJECTS;

     /* Initialize test framework */

     state = SDLTest_CommonCreateState(argv, SDL_INIT_VIDEO);

     if (!state) {

         return 1;

     }

     for (i = 1; i < argc;) {

         int consumed;

         consumed = SDLTest_CommonArg(state, i);

         if (consumed == 0) {

             consumed = -1;

             if (SDL_strcasecmp(argv[i], "--blend") == 0) {

                 if (argv[i + 1]) {

                     if (SDL_strcasecmp(argv[i + 1], "none") == 0) {

                         blendMode = SDL_BLENDMODE_NONE;

                         consumed = 2;

                     } else if (SDL_strcasecmp(argv[i + 1], "blend") == 0) {

                         blendMode = SDL_BLENDMODE_BLEND;

                         consumed = 2;

                     } else if (SDL_strcasecmp(argv[i + 1], "add") == 0) {

                         blendMode = SDL_BLENDMODE_ADD;

                         consumed = 2;

                     } else if (SDL_strcasecmp(argv[i + 1], "mod") == 0) {

                         blendMode = SDL_BLENDMODE_MOD;

                         consumed = 2;

                     }

                 }

             } else if (SDL_strcasecmp(argv[i], "--cyclecolor") == 0) {

                 cycle_color = SDL_TRUE;

                 consumed = 1;

             } else if (SDL_strcasecmp(argv[i], "--cyclealpha") == 0) {

                 cycle_alpha = SDL_TRUE;

                 consumed = 1;

             } else if (SDL_isdigit(*argv[i])) {

                 num_objects = SDL_atoi(argv[i]);

                 consumed = 1;

             }

         }

         if (consumed < 0) {

             SDL_Log("Usage: %s %s [--blend none|blend|add|mod] [--cyclecolor] [--cyclealpha]\n",

                     argv[0], SDLTest_CommonUsage(state));

             return 1;

         }

         i += consumed;

     }

     if (!SDLTest_CommonInit(state)) {

         return 2;

     }

     /* Create the windows and initialize the renderers */

     for (i = 0; i < state->num_windows; ++i) {

         SDL_Renderer *renderer = state->renderers[i];

         SDL_SetRenderDrawBlendMode(renderer, blendMode);

         SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF);

         SDL_RenderClear(renderer);

     }

     srand(time(NULL));

     /* Main render loop */

     frames = 0;

     then = SDL_GetTicks();

     done = 0;

 #ifdef __EMSCRIPTEN__

     emscripten_set_main_loop(loop, 0, 1);

 #else

     while (!done) {

         ++frames;

         loop();

     }

 #endif

     SDLTest_CommonQuit(state);

     /* Print out some timing information */

     now = SDL_GetTicks();

     if (now > then) {

         double fps = ((double) frames * 1000) / (now - then);

         SDL_Log("%2.2f frames per second\n", fps);

     }

     return 0;

 }

 /* vi: set ts=4 sw=4 expandtab: */