本帖最后由 scropioczn 于 2013-7-6 14:17 编辑
7.箭头
根据设想，四个箭头将环绕所选中的球，上下两个箭头负责切换球的颜色，左右则是切换所选中的球。最左，最右，最上，或最下都可以循环。
并且，为了美观：
1. 按键按下去后，相应的箭头将会改变颜色来显示激活。
2.四个球的位置将会按照箭头的位置进行动态调整。平时球与球之间的距离较小，当该球为所选中的球时，左右间隔将拉大以放置左右箭头。（将会在Input里面详细定义）
创建Arrow.h与Arrow.cpp
Arrow.h
[mw_shl_code=cpp,true]/*
* Arrow.h
*
*  Created on: 2013-06-28
*      Author: scropioczn
*  Description: This is the header file of the Arrow class
*  Version:
*/
#ifndef ARROW_H_
#define ARROW_H_
#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include "SDL/SDL_ttf.h"
class Arrow {
private:
//Four inactive arrows
SDL_Surface *up_arrow;
SDL_Surface *down_arrow;
SDL_Surface *left_arrow;
SDL_Surface *right_arrow;
//Four active arrows
SDL_Surface *up_arrow_a;
SDL_Surface *down_arrow_a;
SDL_Surface *left_arrow_a;
SDL_Surface *right_arrow_a;
//activity
bool is_active_up;
bool is_active_down;
bool is_active_left;
bool is_active_right;
//arrow offsets
int arrow_width;
int arrow_height;
public:
//Constructor and destructor
Arrow();
~Arrow();
//----------Gets-----------//
bool isActiveUp();
bool isActiveDown();
bool isActiveLeft();
bool isActiveRight();
int getArrowWidth();
int getArrowHeight();
//----------Sets-----------//
void setActiveUp(bool set);
void setActiveDown(bool set);
void setActiveLeft(bool set);
void setActiveRight(bool set);
//render arrows
void render(int x, int y);
};
#endif /* ARROW_H_ */
[/mw_shl_code]
class中只定义了一个render(), 两个参数即为坐标。四个箭头将会作为一个整体进行显示。
Arrow.cpp
[mw_shl_code=cpp,true]/*
* Arrow.cpp
*
*  Created on: 2013-06-28
*      Author: scropioczn
*  Description: This is the source file containing definitions of Arrow class.
*  Version:
*/
//SDL libraries
#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include "SDL/SDL_ttf.h"
//C/C++ libraries
#include  *本站禁止HTML标签噢*
//Own header file
#include "Arrow.h"
//Linked header files
#include "Utility.h"
#include "Ball.h"
//external objects
extern Ball *ball;
//external variables
extern SDL_Surface *screen;
//Definitions
Arrow::Arrow() {
up_arrow = NULL;
down_arrow = NULL;
left_arrow = NULL;
right_arrow = NULL;
up_arrow_a = NULL;
down_arrow_a = NULL;
left_arrow_a = NULL;
right_arrow_a = NULL;
is_active_up = false;
is_active_down = false;
is_active_left = false;
is_active_right = false;
arrow_width = 0;
arrow_height = 0;
}
Arrow::~Arrow() {
SDL_FreeSurface(up_arrow);
SDL_FreeSurface(down_arrow);
SDL_FreeSurface(left_arrow);
SDL_FreeSurface(right_arrow);
SDL_FreeSurface(up_arrow_a);
SDL_FreeSurface(down_arrow_a);
SDL_FreeSurface(left_arrow_a);
SDL_FreeSurface(right_arrow_a);
}
int Arrow::loadArrow() {
up_arrow = loadImage("data/arrow/arrow_up.png");
down_arrow = loadImage("data/arrow/arrow_down.png");
left_arrow = loadImage("data/arrow/arrow_left.png");
right_arrow = loadImage("data/arrow/arrow_right.png");
up_arrow_a = loadImage("data/arrow/arrow_up_a.png");
down_arrow_a = loadImage("data/arrow/arrow_down_a.png");
left_arrow_a = loadImage("data/arrow/arrow_left_a.png");
right_arrow_a = loadImage("data/arrow/arrow_right_a.png");
if ((up_arrow == NULL) || (down_arrow == NULL) || (left_arrow == NULL)
|| (right_arrow == NULL)) {
return -1;
}
if ((up_arrow_a == NULL) || (down_arrow_a == NULL) || (left_arrow_a == NULL)
|| (right_arrow_a == NULL)) {
return -1;
}
setColorKey(up_arrow, 0xFF, 0xFF, 0xFF);
setColorKey(down_arrow, 0xFF, 0xFF, 0xFF);
setColorKey(left_arrow, 0xFF, 0xFF, 0xFF);
setColorKey(right_arrow, 0xFF, 0xFF, 0xFF);
setColorKey(up_arrow_a, 0xFF, 0xFF, 0xFF);
setColorKey(down_arrow_a, 0xFF, 0xFF, 0xFF);
setColorKey(left_arrow_a, 0xFF, 0xFF, 0xFF);
setColorKey(right_arrow_a, 0xFF, 0xFF, 0xFF);
arrow_width = up_arrow->w;
arrow_height = up_arrow->h;
return 0;
}
bool Arrow::isActiveUp() {
if (is_active_up == true) {
return true;
} else {
return false;
}
}
bool Arrow::isActiveDown() {
if (is_active_down == true) {
return true;
} else {
return false;
}
}
bool Arrow::isActiveLeft() {
if (is_active_left == true) {
return true;
} else {
return false;
}
}
bool Arrow::isActiveRight() {
if (is_active_right == true) {
return true;
} else {
return false;
}
}
int Arrow::getArrowHeight() {
return arrow_height;
}
int Arrow::getArrowWidth() {
return arrow_width;
}
void Arrow::setActiveUp(bool set) {
is_active_up = set;
}
void Arrow::setActiveDown(bool set) {
is_active_down = set;
}
void Arrow::setActiveLeft(bool set) {
is_active_left = set;
}
void Arrow::setActiveRight(bool set) {
is_active_right = set;
}
void Arrow::render(int x, int y) {
int up_x = 0, up_y = 0;
int down_x = 0, down_y = 0;
int left_x = 0, left_y = 0;
int right_x = 0, right_y = 0;
//up
up_x = x + ((ball->getBallWidth() / 2) - (arrow_width / 2));
up_y = y - arrow_height;
//down
down_x = x + ((ball->getBallWidth() / 2) - (arrow_width / 2));
down_y = y + ball->getBallHeight();
//left
left_x = x - arrow_width;
left_y = y + ((ball->getBallHeight() / 2) - (arrow_height / 2));
//right
right_x = x + ball->getBallWidth();
right_y = y + ((ball->getBallHeight() / 2) - (arrow_height / 2));
if (is_active_up == true) {
applySurface(up_x, up_y, up_arrow_a, screen, NULL);
} else if (is_active_up == false) {
applySurface(up_x, up_y, up_arrow, screen, NULL);
}
if (is_active_down == true) {
applySurface(down_x, down_y, down_arrow_a, screen, NULL);
} else if (is_active_down == false) {
applySurface(down_x, down_y, down_arrow, screen, NULL);
}
if (is_active_left == true) {
applySurface(left_x, left_y, left_arrow_a, screen, NULL);
} else if (is_active_left == false) {
applySurface(left_x, left_y, left_arrow, screen, NULL);
}
if (is_active_right == true) {
applySurface(right_x, right_y, right_arrow_a, screen, NULL);
} else if (is_active_right == false) {
applySurface(right_x, right_y, right_arrow, screen, NULL);
}
}[/mw_shl_code]
这里来个小Quiz：请问根据定义，render()里面的两个坐标参数所对应的是球的哪里？
答案在一发的最下，回复答案后可见。