[英]How to set a GUI Button in the win32 window using SDL C++?
Iam soo是SDL和游戲開發領域的新手。 我想制作一個游戲,需要在游戲窗口中放置一個“開始”按鈕。 所以,請問有人可以幫我嗎? 在整個屏幕上沒有鼠標事件,我只想創建一個按鈕來單擊它,在哪里可以插入按鈕的代碼? 這是我的代碼:
int main (int argc, char *argv[]){
int quit = 0;
SDL_Init(SDL_INIT_VIDEO);
SDL_Window* window = NULL;
window = SDL_CreateWindow("Snaykie v1.0",350, 150, 800, 500, SDL_WINDOW_SHOWN);
if (window == NULL){
std::cout << "Can not open the game" << std::endl;
return 0;
}
SDL_Renderer* renderer = NULL;
renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
SDL_Event* evt = new SDL_Event();
SDL_Texture* txt = NULL;
txt = IMG_LoadTexture(renderer, "mainview.bmp");
SDL_Rect rct;
rct.x = 0 ;
rct.y = 0;
rct.h = 500;
rct.w = 800;
SDL_Surface *button = NULL;
while (!quit && evt->type != SDL_QUIT){
SDL_PollEvent(evt);
SDL_RenderClear(renderer);
SDL_RenderCopy(renderer, txt, NULL, &rct);
SDL_RenderPresent(renderer);
}
SDL_DestroyWindow(window);
SDL_DestroyRenderer(renderer);
delete evt;
return 0;
}
它不像一兩行那么簡單。 這是一個例子:
#include <SDL2/SDL.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
typedef struct {
SDL_Rect draw_rect; // dimensions of button
struct {
Uint8 r, g, b, a;
} colour;
bool pressed;
} button_t;
static void button_process_event(button_t *btn, const SDL_Event *ev) {
// react on mouse click within button rectangle by setting 'pressed'
if(ev->type == SDL_MOUSEBUTTONDOWN) {
if(ev->button.button == SDL_BUTTON_LEFT &&
ev->button.x >= btn->draw_rect.x &&
ev->button.x <= (btn->draw_rect.x + btn->draw_rect.w) &&
ev->button.y >= btn->draw_rect.y &&
ev->button.y <= (btn->draw_rect.y + btn->draw_rect.h)) {
btn->pressed = true;
}
}
}
static bool button(SDL_Renderer *r, button_t *btn) {
// draw button
SDL_SetRenderDrawColor(r, btn->colour.r, btn->colour.g, btn->colour.b, btn->colour.a);
SDL_RenderFillRect(r, &btn->draw_rect);
// if button press detected - reset it so it wouldn't trigger twice
if(btn->pressed) {
btn->pressed = false;
return true;
}
return false;
}
int main (int argc, char *argv[]){
int quit = 0;
SDL_Init(SDL_INIT_VIDEO);
SDL_Window* window = NULL;
window = SDL_CreateWindow("",350, 150, 800, 500, SDL_WINDOW_SHOWN);
if (window == NULL){
fprintf(stderr, "create window failed: %s\n", SDL_GetError());
return 1; // 'error' return status is !0. 1 is good enough
}
SDL_Renderer* renderer = NULL;
renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
if(!renderer) { // renderer creation may fail too
fprintf(stderr, "create renderer failed: %s\n", SDL_GetError());
return 1;
}
SDL_Texture* txt = NULL;
SDL_Rect rct;
rct.x = 0 ;
rct.y = 0;
rct.h = 500;
rct.w = 800;
// button state - colour and rectangle
button_t start_button = {
.colour = { .r = 255, .g = 255, .b = 255, .a = 255, },
.draw_rect = { .x = 128, .y = 128, .w = 128, .h = 128 },
};
enum {
STATE_IN_MENU,
STATE_IN_GAME,
} state = 0;
while(!quit) {
SDL_Event evt; // no need for new/delete, stack is fine
// event loop and draw loop are separate things, don't mix them
while(SDL_PollEvent(&evt)) {
// quit on close, window close, or 'escape' key hit
if(evt.type == SDL_QUIT ||
(evt.type == SDL_WINDOWEVENT && evt.window.event == SDL_WINDOWEVENT_CLOSE) ||
(evt.type == SDL_KEYDOWN && evt.key.keysym.sym == SDLK_ESCAPE)) {
quit = 1;
}
// pass event to button
button_process_event(&start_button, &evt);
}
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
// SDL_RenderCopy(renderer, txt, NULL, &rct);
if(state == STATE_IN_MENU) {
if(button(renderer, &start_button)) {
printf("start button pressed\n");
state = STATE_IN_GAME; // state change - button will not be drawn anymore
}
} else if(state == STATE_IN_GAME) {
/* your game logic */
}
SDL_RenderPresent(renderer);
}
SDL_DestroyWindow(window);
SDL_DestroyRenderer(renderer);
return 0;
}
(它是C,但這里不是重點)。 它繪制一個簡單的常色矩形並檢測其上的點擊。 用例如紋理代替矩形很簡單; 添加文本可能會有點困難,使用SDL_ttf可能是最簡單的方法。
可能會根據您想要獲得的內容以多種方式進行改進。 例如,它在按下鼠標按鈕時做出反應,而在某些情況下,您可能希望對按鈕的釋放做出反應,並跟蹤其按下和釋放的位置。 而且,如果您有許多按鈕,則在每個按鈕上調用事件更新是很丑陋的,因此您可能希望為此使用不同的系統。 您可能還希望具有非矩形的按鈕(例如,由圖像指定的某些形狀)-這將需要完全不同的方法,因為您需要檢查鼠標是否與形狀蒙版相對應。
我建議看一下imgui 。
附帶說明一下,不要new
SDL_Event
,這絕對沒有意義。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.