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从0开始使用面对对象C语言搭建一个基于OLED的图形显示框架（基础图形库实现）

news 来源：原创 2025/5/14 14:40:30

基础图形库的抽象

抽象图形

抽象点

设计我们的抽象

实现我们的抽象

测试

抽象线

设计我们的抽象

实现我们的抽象

绘制垂直的和水平的线

使用Bresenham算法完成任意斜率的绘制

绘制三角形和矩形

矩形

三角形

实现

绘制圆，圆弧和椭圆

继续我们的测试

基础图形库的抽象

历经千辛万苦，我们终于可以开始行动起来，绘制图形了。我们将要绘制线，矩形，圆，椭圆等一系列基础的图形。问我其他的绘制呢？不必着急，我们慢慢来谈。

有没有发现我们现在的谈论越来越高层了？我们现在绘制图像的时候还会关心我用的是硬件IIC或者是软件SPI吗？不会，你甚至可能才意识到我们使用的是OLED！这就是抽象带给我们的好处。我们现在脑子里只有抽象的绘图设备这个概念。它可以绘制点，面。仅此而已。

本篇的代码在：MCU_Libs/OLED/library/Graphic/base at main · Charliechen114514/MCU_Libs (github.com)

抽象图形

抽象点

设计我们的抽象

我们即将迈出我们的第一步，那就是绘制一个点。

typedef uint16_t    PointBaseType;
/*x:  The x-coordinate of the pointy:  The y-coordinate of the pointoperations: An instance of CCGraphic_BaseOperations that stores operations or behaviors related to the point, likely used for drawing or other graphical manipulations.
*/
typedef struct __CCGraphic_Point{PointBaseType                     x;PointBaseType                     y;
}CCGraphic_Point;

void CCGraphic_init_point(CCGraphic_Point* point, PointBaseType x, PointBaseType y);
void CCGraphic_draw_point(CCDeviceHandler* handler, CCGraphic_Point* point);

一个点的基本组成，就是给定一个由两个数的组合——X和Y，长度上，笔者为了防止特大设备，使用了PointBaseType隔离了具体的长度大小。

小技巧：

当你发现一个问题很复杂的时候，最好的办法就是隔离！将大问题分解为若干的小问题，以笔者上面遇到的困难为例子。如何保证自己的点可以分布在满足设备宽度的平面上呢？答案是分解问题：点分布在平面上，使用的是对平面属性的PointBaseType上，他只知道自己属于这个类型，就一定不会超越所在的平面，不会出现绘图平面过大导致使用的数据类型发生溢出，至于如何保证不发生溢出呢？那是另一个问题，笔者使用的架构下，不会出现uint16_t不够使用的问题。但是如果的确出现了超大设备，我只需要轻而易举的定义一个HYPER_LARGE_DEVICE的宏，或者是面对资源极端紧张的嵌入式设备，定义一个HYPER_SMALL_DEVICE，就可以让所有的资源占用瞬间缩小一半
#ifdef  HYPER_LARGE_DEVICE
typedef uint32_t    PointBaseType;
#elif defined(HYPER_SMALL_DEVICE)
typedef uint8_t     PointBaseType;
#else
typedef uint16_t    PointBaseType;
#endif
而我其他的代码一行都不用动，轻而易举的完成了迁移。

实现我们的抽象

让我们看看我们的代码多么简洁吧！

#include "Graphic/base/CCGraphic_Point/CCGraphic_Point.h"
#include "Graphic/CCGraphic_device_adapter.h"

void CCGraphic_draw_point(CCDeviceHandler* handler, CCGraphic_Point* point)
{handler->operations.set_pixel_device_function(handler, point->x, point->y);
}

void CCGraphic_init_point(CCGraphic_Point* point, PointBaseType x, PointBaseType y)
{point->x = x;point->y = y;
}

绘制一个点，就是调用了设备的绘制点的办法。你问我咋绘制的？啥？你需要关心吗？我不说你可能都不知道我是拿的LCD做测试呢（笑），但是，这里我需要严肃提醒的是——不要在关心实时性的绘图设备上这样做，让我们看一看调用链就好了：

CCGraphic_draw_point -> set_pixel_device_function(实际上就是setpixel_device_oled) -> oled_helper_setpixel

也就是说，我们多调用了两次functions来换取对任意设备的抽象。但是我也可以一行代码不改，就可以完全把调用链换成

CCGraphic_draw_point -> set_pixel_device_function(实际上就是setpixel_device_lcd) -> lcd_helper_setpixel

多简单！

测试

现在我们就可以开始测试了

OLED_HARD_IIC_Private_Config pvt_config;
OLED_Handle handle;
CCGraphic_OLED_Config config;

void on_test_init_hardiic_oled(CCDeviceHandler* device)
{bind_hardiic_handle(&pvt_config, &hi2c1, 0x78, HAL_MAX_DELAY);config.createType = OLED_HARD_IIC_DRIVER_TYPE;config.related_configs = &pvt_config;register_oled_paintdevice(device, &handle, &config);
}

void on_test_draw_points(CCDeviceHandler* handle)
{CCGraphic_Point point;CCGraphic_init_point(&point, 0, 0);for(uint8_t i = 0; i < 20; i++){point.x = i;point.y = i * 2;CCGraphic_draw_point(handle, &point);}handle->operations.update_device_function(handle);
}

// at main.c
CCDeviceHandler handler;
on_test_init_hardiic_oled(&handler);
on_test_draw_points(&handler);

不出意外的话不会有任何问题。

抽象线

线的绘制开始有所讲究了，我们需要使用更好的，不涉及浮点数运算的办法来尽可能的回避耗费时间的浮点数运算。这隶属于计算机架构体系的内容，关于ARM，计算浮点数远远比计算整数的开销大（除非使用的是更贵的特化硬件）。现在，让我们开始绘制线线

设计我们的抽象

笔者建议你看到这里了，先自己构思一下如果是你，你如何抽象呢？

笔者先给你看看江科大的代码

void OLED_DrawLine(int16_t X0, int16_t Y0, int16_t X1, int16_t Y1)
{...
}

啥？你问我抽象呢？怎么是实现呢？我只能说——它的函数签名就是抽象咯（笑）。各种处理混在一起，是这样的代码非常难读的一个根本原因。

笔者揭晓我的抽象。

#include "Graphic/base/CCGraphic_Base.h"
#include "Graphic/base/CCGraphic_Point/CCGraphic_Point.h"

typedef struct __CCGraphic_Line{CCGraphic_Point p_left;CCGraphic_Point p_right;
}CCGraphic_Line;

void CCGraphic_init_line(   CCGraphic_Line* line, CCGraphic_Point pl, CCGraphic_Point pr);

void CCGraphic_draw_line(CCDeviceHandler* handler, CCGraphic_Line* line);

一个争论：

这样实现好不好啊？
typedef struct __CCGraphic_Line{CCGraphic_Point* p_left;CCGraphic_Point* p_right;
}CCGraphic_Line;
笔者思考过，事实上，笔者第一代的OLED框架（当然，远远没有现在的那么完善，也远远没有现在的好，甚至还有bug）就是这样实现的。我既然跟上面的实现不一致，那显然，有好处也就有坏处。

我们需要思考的是——我们的对象指针和对象本身表达的含义的区别是什么。关于这个说法，婆说婆有理，公说公有理，笔者这里给出的看法是：

对象本身在结构体中的声明是一种上层抽象对底层对象的强所属权，也就是说，对于每一个整个结构体模板刻出来的结构体对象的成员而言，内部所拥有的点都是独一无二的。换而言之：这就是我的资源，不是借的，更不是偷的！所以现在笔者采用的抽象，更加像是线对点宣誓了主权，这就是线组成的点，没有任何可以商量的余地。

对象指针则是一种弱的引用，表达的是一种借用。上面使用指针占用的抽象，更加像是：借来了两个点，然后用一下这两个点来描述了一下一根直线。用完了对象释放干净了，也就作罢了，但是点本身不会消失。就像我们用一根笔连起来了两个点，组成了一根线，现在我们只是把线擦除了，但是点还在呢！它还可以用来做别的事情。

从内存占用上来看，在ARM32体系上，我们都知道指针的大小是32位，4个字节，所以，我们一个sizeof就能得到使用指针抽象的线也就是8个字节。是一个恒定的大小。对于现在笔者采用的抽象，则是2倍的CCGraphic_Point大小，随着不同的PointBaseType, Line自身的大小也会发生波动，在uint8_t设备上，我们一共是4个字节大小，比指针描述的小，在uint16_t上则是不分伯仲，对于超大设备Line的大小就会膨胀为指针实现的两倍。

但是，另一方面，正如我所说的，这样的资源只是借用，他必须存在于哪个地方，问题来了，你能保证你所使用的点总是有效的吗？
CCGraphic_Line  l;
{CCGraphic_Point tl;CCGraphic_Point br;CCGraphic_init_line(&l, tl, br);
}
// 在这里使用还安全嘛？
CCGraphic_draw_line(&handle, &l);
你也许知道你使用的对象是有效的，但是客户程序员呢？他不知道啊？随后应用层的程序因为非法的内存访问崩溃了（进入了Hard_Fault），他还要幸幸苦苦看你的实现，然后沮丧的调试了一天发现是库作者这个家伙居然只是借用点！最后代来的时间的开销是任何人都无法接受的，这样不确定的风险分明更加的剧烈。

笔者想要说的是：每一个设计都有它的优点和缺点，作为一个合格的程序员，不管是嵌入式程序员，还是架构设计师，都需要明确的表达自己资源的所属权，以及，不要违反“最小惊讶原则”（例子：这个怎么资源突然非法了！为什么库没有帮助我维护？？？）

实现我们的抽象

规避浮点数运算！这个是我早就说了的。我们需要请出的算法就是Bresenham (montana.edu)算法，这个算法本质上使用的是DDA算法，一种整数微分思维。我们对得到的微分做一次取整，得到的就是整数的点（这是可以接受的，我们没办法在一个LCD或者是OLED上绘制坐标为(1.25, 4.75)的点，不是吗？）

为了化简，我们对绘制直线进行分类讨论

绘制一条垂直的线
绘制一条水平的线
绘制任意斜率的线

void CCGraphic_draw_line(CCDeviceHandler* handler, CCGraphic_Line* line)
{ // test if the verticalif(line->p_left.x == line->p_right.x) return __on_handle_vertical_line(handler, line);   if(line->p_left.y == line->p_right.y)return __on_handle_horizental_line(handler, line);return __pvt_BresenhamMethod_line(handler, line);
}

没想到吧，笔者就用了这几行，完成了这几个事情。好吧，我承认这样有点耍赖了。实际上内部还是颇为复杂，但是，绘制垂直还有水平的线是轻而易举的，试一试？来看看笔者的代码吧！

绘制垂直的和水平的线

/*draw the lines that matches the equal x
*/
static void __on_handle_vertical_line(CCDeviceHandler* handler,CCGraphic_Line* line
)
{PointBaseType max_y = max_uint16(line->p_left.y, line->p_right.y);PointBaseType min_y = min_uint16(line->p_left.y, line->p_right.y);CCGraphic_Point p;p.x = line->p_left.x;for(PointBaseType i = min_y; i <= max_y; i++){p.y = i;CCGraphic_draw_point(handler, &p);}
}

static void __on_handle_horizental_line(CCDeviceHandler* handler,CCGraphic_Line* line
)
{PointBaseType max_x = max_uint16(line->p_left.x, line->p_right.x);PointBaseType min_x = min_uint16(line->p_left.x, line->p_right.x);CCGraphic_Point p;p.y = line->p_left.y;for(PointBaseType i = min_x; i <= max_x; i++){p.x = i;CCGraphic_draw_point(handler, &p);}
}

我下面来谈论一下一些要点：

解释一下max_uint16和min_uint16?

没啥好解释的啊？这个就是择取大者和小者，有啥好说的呢？

为什么变量没有像江科大那样一股脑堆在前面呢？

笔者可以给出充分的原因：我希望变量出现在它该出现的位置，比起来，你也不喜欢看变量一坨屎拉在了函数的前面，下面看实现的时候漫天找这个变量在哪里吧。没那个必要！但是这个需要看情况，如果作者实在不会哪怕一丁点的函数设计，把代码一股脑的堆到了一个函数里，那还不如江科大的变量写法！
为什么不考虑
{PointBaseType max_y = max_uint16(line->p_left.y, line->p_right.y);PointBaseType min_y = min_uint16(line->p_left.y, line->p_right.y);for(PointBaseType i = min_y; i <= max_y; i++){CCGraphic_Point p;p.x = line->p_left.x;p.y = i;CCGraphic_draw_point(handler, &p);}
}
这个是经典的效率之争。你相信所有的编译器，都会意识到：“哦我的天，这个程序员是一个白痴，p的X坐标永远不会改变，这个白痴为什么要重新赋值一个相同的值max_y - min_y + 1次呢？”嘛？ 你不敢！，你永远也不知道使用你的代码的人，在用着怎样的老毕等编译器，他对这样的优化足够迟钝，以至于他对你那可怜的栈来来回回弹弹压压，让你的程序性能被砍到惊呼国骂。你敢打赌使用你库的代码的人，足够的现代嘛？那么，不如让我们的表述更加的明白
{PointBaseType max_x = max_uint16(line->p_left.x, line->p_right.x);PointBaseType min_x = min_uint16(line->p_left.x, line->p_right.x);CCGraphic_Point p;p.y = line->p_left.y;for(PointBaseType i = min_x; i <= max_x; i++){p.x = i;CCGraphic_draw_point(handler, &p);}
}
这样的代码的开销瞬间压到只剩下一次地址解引用和赋值操作了，一下子无论何种编译器，都能生成最为高效的字节码。
参数设计的时候，对于复杂抽象类型，使用指针还是使用结构体本身传递参数？

ARM32体系架构有16个寄存器，不同于x86老毕等，传递个结构体最后压内存去了，一些简单的POD类型（我们的Point就是一个简单的POD类型，只有数据没有方法）回直接解析内部的类型是整数，直接传送到寄存器中，将效率提升十几倍，而不用访问内存。这样看，对于一部分最为简单的结构体，直接传递对象本身不是一件特别耗操作的事情，但是，笔者仍然建议：如果你希望这个资源只是被借用一下，或者，表达传递的就是这个对象本身，他在ARM广阔的内存海洋是独一无二的话，使用指针，哪怕他就一个字节大小！

所以，为什么在函数前面的最前面添加static

可惜了我们的C语言程序设计表达私有只能使用static办法，这表明，这个函数只能在文件内部访问，实际上的函数签名会被独特标记，导致外部生成的签名无法对应于实际上被static修饰的函数，这也就意味着无法通过编译！他没办法认识这个被static修饰的函数。至于其他乱七八糟的什么重名问题，我负责的告诉你，不要指望所有编译器都会正确的反应你的UB行为，不然，你就会在“编译了半天发现被这个问题绊了一跤”和“这个程序的行为怎么这么诡异啊？不是跳转道我想要的函数”中二选一了，反正代价是你的一天被你的UB行为坑害（笑）

使用Bresenham算法完成任意斜率的绘制

// Bresenham's Line Algorithm, designed to avoid floating point calculations
// References: https://www.cs.montana.edu/courses/spring2009/425/dslectures/Bresenham.pdf
// https://www.bilibili.com/video/BV1364y1d7Lo
void __pvt_BresenhamMethod_line(CCDeviceHandler* handler, CCGraphic_Line* line)
{
#define __pvt_fast_draw_point(X, Y) \do { \p.x = X; \p.y = Y; \CCGraphic_draw_point(handler, &p); \} while(0)
// Define initial points for the line: p_left and p_right represent the endpointsint16_t startX = line->p_left.x;int16_t startY = line->p_left.y;int16_t endX = line->p_right.x;int16_t endY = line->p_right.y;
// Flags to indicate transformations of coordinatesuint8_t isYInverted = 0, isXYInverted = 0;{// If the start point's X coordinate is greater than the end point's X, swap the pointsif (startX > endX) {// Swap the X and Y coordinates for the start and end pointsswap_int16(&startX, &endX);swap_int16(&startY, &endY);}
// If the start point's Y coordinate is greater than the end point's Y, invert the Y coordinatesif (startY > endY) {// Invert Y coordinates to make the line direction consistent in the first quadrantstartY = -startY;endY = -endY;// Set the flag indicating Y coordinates were invertedisYInverted = 1;}
// If the line's slope (dy/dx) is greater than 1, swap X and Y coordinates for a shallower slopeif (endY - startY > endX - startX) {// Swap X and Y coordinates for both pointsswap_int16(&startX, &startY);swap_int16(&endX, &endY);// Set the flag indicating both X and Y coordinates were swappedisXYInverted = 1;}
// Calculate differences (dx, dy) and the decision variables for Bresenham's algorithmconst int16_t dx = endX - startX;const int16_t dy = endY - startY;const int16_t incrE = 2 * dy;  // Increment for eastward movementconst int16_t incrNE = 2 * (dy - dx);  // Increment for northeastward movement
int16_t decision = 2 * dy - dx;  // Initial decision variableint16_t x = startX;  // Starting X coordinateint16_t y = startY;  // Starting Y coordinate
// Draw the starting point and handle coordinate transformations based on flagsCCGraphic_Point p;if (isYInverted && isXYInverted) {__pvt_fast_draw_point(y, -x);} else if (isYInverted) {__pvt_fast_draw_point(x, -y);} else if (isXYInverted) {__pvt_fast_draw_point(y, x);} else {__pvt_fast_draw_point(x, y);}
// Iterate through the X-axis to draw the rest of the linewhile (x < endX) {x++;  // Increment X coordinateif (decision < 0) {decision += incrE;  // Move eastward if decision variable is negative} else {y++;  // Move northeastward if decision variable is positive or zerodecision += incrNE;}
// Draw each point along the line with coordinate transformation as neededif (isYInverted && isXYInverted) {__pvt_fast_draw_point(y, -x);} else if (isYInverted) {__pvt_fast_draw_point(x, -y);} else if (isXYInverted) {__pvt_fast_draw_point(y, x);} else {__pvt_fast_draw_point(x, y);}}}
#undef __pvt_fast_draw_point
}

好长一大串，先不必着急，我一步步慢慢说。实际上，这个算法除了使用DDA以外，还用了化未知为已知的办法。我的意思是：

        // If the start point's X coordinate is greater than the end point's X, swap the pointsif (startX > endX) {// Swap the X and Y coordinates for the start and end pointsswap_int16(&startX, &endX);swap_int16(&startY, &endY);}
// If the start point's Y coordinate is greater than the end point's Y, invert the Y coordinatesif (startY > endY) {// Invert Y coordinates to make the line direction consistent in the first quadrantstartY = -startY;endY = -endY;// Set the flag indicating Y coordinates were invertedisYInverted = 1;}

首先，确保我们的线总是向正的，斜率总是大于0

    // If the line's slope (dy/dx) is greater than 1, swap X and Y coordinates for a shallower slopeif (endY - startY > endX - startX) {// Swap X and Y coordinates for both pointsswap_int16(&startX, &startY);swap_int16(&endX, &endY);// Set the flag indicating both X and Y coordinates were swappedisXYInverted = 1;}

上面则是在斜率大于1的基础上，将变换映射到介于0 < k < 1的范围上。

最后，使用核心算法直接绘制

        // Calculate differences (dx, dy) and the decision variables for Bresenham's algorithmconst int16_t dx = endX - startX;const int16_t dy = endY - startY;const int16_t incrE = 2 * dy;  // Increment for eastward movementconst int16_t incrNE = 2 * (dy - dx);  // Increment for northeastward movement
int16_t decision = 2 * dy - dx;  // Initial decision variableint16_t x = startX;  // Starting X coordinateint16_t y = startY;  // Starting Y coordinate
// Draw the starting point and handle coordinate transformations based on flagsCCGraphic_Point p;if (isYInverted && isXYInverted) {__pvt_fast_draw_point(y, -x);} else if (isYInverted) {__pvt_fast_draw_point(x, -y);} else if (isXYInverted) {__pvt_fast_draw_point(y, x);} else {__pvt_fast_draw_point(x, y);}
// Iterate through the X-axis to draw the rest of the linewhile (x < endX) {x++;  // Increment X coordinateif (decision < 0) {decision += incrE;  // Move eastward if decision variable is negative} else {y++;  // Move northeastward if decision variable is positive or zerodecision += incrNE;}
// Draw each point along the line with coordinate transformation as neededif (isYInverted && isXYInverted) {__pvt_fast_draw_point(y, -x);} else if (isYInverted) {__pvt_fast_draw_point(x, -y);} else if (isXYInverted) {__pvt_fast_draw_point(y, x);    // 对角对称，互换XY即可变换} else {__pvt_fast_draw_point(x, y);}}}

这个代码就是直接翻译了我给的PDF的算法，下面来聊一聊算法之外的：

使用宏来化简我们的工作
#define __pvt_fast_draw_point(X, Y) \do { \p.x = X; \p.y = Y; \CCGraphic_draw_point(handler, &p); \} while(0)
这个是一个简单的封装宏，为什么使用do..while请参考笔者之前的博客（协议篇）

C没有constexpr，没有模板，有的时候会显得十分贫瘠，所以，我们只好忍一下，使用宏完成重复的，0开销的工作。

绘制三角形和矩形

矩形

#ifndef CCGraphic_Rectangle_H
#define CCGraphic_Rectangle_H

#include "Graphic/base/CCGraphic_Base.h"
#include "Graphic/base/CCGraphic_Point/CCGraphic_Point.h"

typedef struct __CCGraphic_Rectangle{CCGraphic_Point         top_left;CCGraphic_Point         bottom_right;
}CCGraphic_Rectangle;

void CCGraphic_init_rectangle(CCGraphic_Rectangle* rect, CCGraphic_Point tl, CCGraphic_Point br);

void CCGraphic_draw_rectangle(CCDeviceHandler* handler, CCGraphic_Rectangle* rect);

void CCGraphic_drawfilled_rectangle(CCDeviceHandler* handler, CCGraphic_Rectangle* rect);

#endif

三角形

#ifndef CCGraphic_Triangle_H
#define CCGraphic_Triangle_H

#include "Graphic/base/CCGraphic_Base.h"
#include "Graphic/base/CCGraphic_Point/CCGraphic_Point.h"

typedef struct __CCGraphic_Triangle
{CCGraphic_Point     p1;CCGraphic_Point     p2;CCGraphic_Point     p3;
}CCGraphic_Triangle;


void CCGraphic_init_triangle(CCGraphic_Triangle* triangle, CCGraphic_Point     p1,CCGraphic_Point     p2,CCGraphic_Point     p3
);

void CCGraphic_draw_triangle(CCDeviceHandler*    handle,CCGraphic_Triangle* triangle
);

void CCGraphic_drawfilled_triangle(CCDeviceHandler*    handle,CCGraphic_Triangle* triangle
);

#endif

实现

我们还是使用Bresenham算法和Franklin算法完成我们对三角形和矩形的绘制

#include "Graphic/base/CCGraphic_Triangle/CCGraphic_Triangle.h"
#include "Graphic/base/CCGraphic_Line/CCGraphic_Line.h"
#include "Graphic/CCGraphic_device_adapter.h"
#include "Graphic/common/CCGraphic_Utils.h"

void CCGraphic_init_triangle(CCGraphic_Triangle* triangle, CCGraphic_Point     p1,CCGraphic_Point     p2,CCGraphic_Point     p3
)
{triangle->p1 = p1;triangle->p2 = p2;triangle->p3 = p3;
}

void CCGraphic_draw_triangle(CCDeviceHandler*    handle,CCGraphic_Triangle* triangle
)
{CCGraphic_Line  line;CCGraphic_init_line(&line, triangle->p1, triangle->p2);CCGraphic_draw_line(handle, &line);handle->operations.update_device_function(handle);CCGraphic_init_line(&line, triangle->p2, triangle->p3);CCGraphic_draw_line(handle, &line);handle->operations.update_device_function(handle);CCGraphic_init_line(&line, triangle->p1, triangle->p3);CCGraphic_draw_line(handle, &line);
}

static uint8_t __pvt_is_in_triangle(int16_t* triangles_x,int16_t* triangles_y,CCGraphic_Point* p)
{uint8_t is_in = 0;/*此算法由W. Randolph Franklin提出*//*参考链接：https://wrfranklin.org/Research/Short_Notes/pnpoly.html*/for (uint8_t i = 0, j = 2; i < 3; j = i++){if (((triangles_y[i] > p->y) != (triangles_y[j] > p->y)) &&(p->x < (triangles_x[j] - triangles_x[i]) * (p->y - triangles_y[i]) / (triangles_y[j] - triangles_y[i]) + triangles_x[i])){is_in = !is_in;}}return is_in;
}

void CCGraphic_drawfilled_triangle(CCDeviceHandler*    handle,CCGraphic_Triangle* triangle
)
{int16_t triangles_x[] = {triangle->p1.x, triangle->p2.x, triangle->p3.x};
int16_t triangles_y[] = {triangle->p1.y, triangle->p2.y, triangle->p3.y};
int16_t minX = find_int16min(triangles_x, 3);int16_t minY = find_int16min(triangles_y, 3);
int16_t maxX = find_int16max(triangles_x, 3);int16_t maxY = find_int16max(triangles_y, 3);CCGraphic_Point p;p.x = minX;p.y = minY;for(int16_t i = minX; i < maxX; i++){for(int16_t j = minY; j < maxY; j++){p.x = i;p.y = j;if(__pvt_is_in_triangle(triangles_x, triangles_y, &p)){CCGraphic_draw_point(handle, &p);}}}

}

#include "Graphic/base/CCGraphic_Rectangle/CCGraphic_Rectangle.h"
#include "Graphic/base/CCGraphic_Line/CCGraphic_Line.h"

void CCGraphic_init_rectangle(CCGraphic_Rectangle* rect, CCGraphic_Point tl, CCGraphic_Point br)
{rect->top_left = tl;rect->bottom_right = br;
}

void CCGraphic_draw_rectangle(CCDeviceHandler* handler, CCGraphic_Rectangle* rect)
{CCGraphic_Line l;CCGraphic_Point tmp;
// draw top, set tmp as the top_righttmp.x = rect->bottom_right.x;tmp.y = rect->top_left.y;CCGraphic_init_line(&l, rect->top_left, tmp);CCGraphic_draw_line(handler, &l);
// draw rightCCGraphic_init_line(&l, tmp, rect->bottom_right);CCGraphic_draw_line(handler, &l);    
// draw lefttmp.x = rect->top_left.x;tmp.y = rect->bottom_right.y;CCGraphic_init_line(&l, rect->top_left, tmp);CCGraphic_draw_line(handler, &l);      
// draw bottomCCGraphic_init_line(&l,tmp, rect->bottom_right);CCGraphic_draw_line(handler, &l);      
}


void CCGraphic_drawfilled_rectangle(CCDeviceHandler* handler, CCGraphic_Rectangle* rect)
{CCGraphic_Point p;for(PointBaseType iterate_x = rect->top_left.x; iterate_x <= rect->bottom_right.x; iterate_x++){p.x = iterate_x;for(PointBaseType iterate_y = rect->top_left.y; iterate_y <= rect->bottom_right.y; iterate_y++){p.y = iterate_y;CCGraphic_draw_point(handler, &p);}        }
}

小问题：提示，矩形的填充绘制是可以优化，你认为应该如何优化呢？（提示：我们是不是用错了device的功能了？）（可以在评论区回答的）

绘制圆，圆弧和椭圆

没有什么特殊的，笔者出于一些人上不去github，先把代码放到这里。

MCU_Libs/OLED/library/Graphic/base at main · Charliechen114514/MCU_Libs (github.com)

#ifndef CCGraphic_Arc_H
#define CCGraphic_Arc_H
#include "Graphic/base/CCGraphic_Base.h"
#include "Graphic/base/CCGraphic_Point/CCGraphic_Point.h"

typedef struct __CCGraphic_Arc{CCGraphic_Point     center;PointBaseType       radius;int16_t             start_degree;int16_t             end_degree;
}CCGraphic_Arc;

void CCGraphic_init_CCGraphic_Arc(CCGraphic_Arc*      handle,CCGraphic_Point     center,PointBaseType       radius,int16_t             start_degree,int16_t             end_degree  
);

void CCGraphic_draw_arc(CCDeviceHandler* handler,CCGraphic_Arc* handle
);

void CCGraphic_drawfilled_arc(CCDeviceHandler* handler,CCGraphic_Arc* handle
);

#endif

#ifndef __CCGraphic_Circle_H
#define __CCGraphic_Circle_H
#include "Graphic/base/CCGraphic_Base.h"
#include "Graphic/base/CCGraphic_Point/CCGraphic_Point.h"

typedef struct __CCGraphic_Circle
{CCGraphic_Point             center;PointBaseType               radius;
}CCGraphic_Circle;

void CCGraphic_init_circle(CCGraphic_Circle* circle, CCGraphic_Point c, uint8_t radius);
void CCGraphic_draw_circle(CCDeviceHandler* handler, CCGraphic_Circle* circle);
void CCGraphic_drawfilled_circle(CCDeviceHandler* handler, CCGraphic_Circle* circle);
#endif

#ifndef CCGraphic_Ellipse_H
#define CCGraphic_Ellipse_H
#include "Graphic/base/CCGraphic_Base.h"
#include "Graphic/base/CCGraphic_Point/CCGraphic_Point.h"

typedef struct __CCGraphic_Ellipse{CCGraphic_Point                 center;PointBaseType                   X_Radius;PointBaseType                   Y_Radius;  
}CCGraphic_Ellipse;

void CCGraphic_init_ellipse(CCGraphic_Ellipse*          handle, CCGraphic_Point             center,PointBaseType               X_Radius,PointBaseType               Y_Radius 
);

void CCGraphic_draw_ellipse(CCDeviceHandler* handler,CCGraphic_Ellipse* ellipse
);

void CCGraphic_drawfilled_ellipse(CCDeviceHandler* handler,CCGraphic_Ellipse* ellipse
);

#endif

实现如下

#include "Graphic/base/CCGraphic_Arc/CCGraphic_Arc.h"
#include <math.h>

void CCGraphic_init_CCGraphic_Arc(CCGraphic_Arc*      handle,CCGraphic_Point     center,PointBaseType       radius,int16_t             start_degree,int16_t             end_degree  
)
{handle->center          = center;handle->end_degree      = end_degree;handle->start_degree    = start_degree;handle->radius          = radius;
}

static uint8_t __pvt_is_in_angle(int16_t x, int16_t y, int16_t start, int16_t end)
{int16_t point_angle = (atan2(y, x) / 3.14 * 180);// 笔者的一个更加清晰的写法// if (start < end) //起始角度小于终止角度的情况// {//  /*如果指定角度在起始终止角度之间，则判定指定点在指定角度*///  if (point_angle >= start && point_angle <= end)//  {//      return 1;//  }// }// else         //起始角度大于于终止角度的情况// {//  /*如果指定角度大于起始角度或者小于终止角度，则判定指定点在指定角度*///  if (point_angle >= start || point_angle <= end)//  {//      return 1;//  }// }// return 0;    
return start < end ?(start < point_angle && point_angle < end):(start > point_angle || point_angle > end);
}

#define DRAW_OFFSET_POINT(offsetx, offsety) \do{\point.x = handle->center.x + (offsetx);\point.y = handle->center.y + (offsety);\CCGraphic_draw_point(handler, &point);\}while(0)

#define DRAW_IF_IN(offsetx, offsety) \do{\if (__pvt_is_in_angle((offsetx), (offsety), start_angle, end_angle))    {\DRAW_OFFSET_POINT(offsetx, offsety);\}\}while(0)   

void CCGraphic_draw_arc(CCDeviceHandler* handler,CCGraphic_Arc* handle
)
{/*此函数借用Bresenham算法画圆的方法*/   int16_t x = 0;int16_t y = handle->radius;int16_t d = 1 - y;
CCGraphic_Point point;const int16_t start_angle = handle->start_degree;const int16_t end_angle = handle->end_degree;/*在画圆的每个点时，判断指定点是否在指定角度内，在，则画点，不在，则不做处理*/DRAW_IF_IN(x, y);DRAW_IF_IN(-x, -y);DRAW_IF_IN(y, x);DRAW_IF_IN(-y, -x);while (x < y)       //遍历X轴的每个点{x ++;if (d < 0)      //下一个点在当前点东方{d += 2 * x + 1;}else            //下一个点在当前点东南方{y --;d += 2 * (x - y) + 1;}/*在画圆的每个点时，判断指定点是否在指定角度内，在，则画点，不在，则不做处理*/DRAW_IF_IN(x, y);DRAW_IF_IN(y, x);DRAW_IF_IN(-x, -y);DRAW_IF_IN(-y, -x);DRAW_IF_IN(x, -y);DRAW_IF_IN(y, -x);DRAW_IF_IN(-x, y);DRAW_IF_IN(-y, x);}
}

void CCGraphic_drawfilled_arc(CCDeviceHandler* handler,CCGraphic_Arc* handle
)
{/*此函数借用Bresenham算法画圆的方法*/   int16_t x = 0;int16_t y = handle->radius;int16_t d = 1 - y;
CCGraphic_Point point;const int16_t start_angle = handle->start_degree;const int16_t end_angle = handle->end_degree;point.x = x;point.y = y;/*在画圆的每个点时，判断指定点是否在指定角度内，在，则画点，不在，则不做处理*/DRAW_IF_IN(x, y);DRAW_IF_IN(-x, -y);DRAW_IF_IN(y, x);DRAW_IF_IN(-y, -x);
/*遍历起始点Y坐标*/for (int16_t j = -y; j < y; j ++){/*在填充圆的每个点时，判断指定点是否在指定角度内，在，则画点，不在，则不做处理*/DRAW_IF_IN(0, j);}while (x < y)       //遍历X轴的每个点{x ++;if (d < 0)      //下一个点在当前点东方{d += 2 * x + 1;}else            //下一个点在当前点东南方{y --;d += 2 * (x - y) + 1;}/*在画圆的每个点时，判断指定点是否在指定角度内，在，则画点，不在，则不做处理*/DRAW_IF_IN(x, y);DRAW_IF_IN(y, x);DRAW_IF_IN(-x, -y);DRAW_IF_IN(-y, -x);DRAW_IF_IN(x, -y);DRAW_IF_IN(y, -x);DRAW_IF_IN(-x, y);DRAW_IF_IN(-y, x);
/*遍历中间部分*/for (int16_t j = -y; j < y; j ++){/*在填充圆的每个点时，判断指定点是否在指定角度内，在，则画点，不在，则不做处理*/DRAW_IF_IN(x, j);DRAW_IF_IN(-x, j);}/*遍历两侧部分*/for (int16_t j = -x; j < x; j ++){/*在填充圆的每个点时，判断指定点是否在指定角度内，在，则画点，不在，则不做处理*/DRAW_IF_IN(y, j);DRAW_IF_IN(-y, j);}}
}

#undef DRAW_OFFSET_POINT
#undef DRAW_IF_IN

#include "Graphic/base/CCGraphic_Ellipse/CCGraphic_Ellipse.h"

void CCGraphic_init_ellipse(CCGraphic_Ellipse*          handle, CCGraphic_Point             center,PointBaseType               X_Radius,PointBaseType               Y_Radius 
)
{handle->center = center;handle->X_Radius = X_Radius;handle->Y_Radius = Y_Radius;
}

#define DRAW_OFFSET_POINT(offsetx, offsety) \do{\point.x = ellipse->center.x + (offsetx);\point.y = ellipse->center.y + (offsety);\CCGraphic_draw_point(handler, &point);\}while(0)

#define SQUARE(X) ((X) * (X))

void CCGraphic_draw_ellipse(CCDeviceHandler* handler,CCGraphic_Ellipse* ellipse
)
{const int16_t x_radius = ellipse->X_Radius;const int16_t y_radius = ellipse->Y_Radius;
// Bresenham's Ellipse Algorithm to avoid costly floating point calculations// Reference: https://blog.csdn.net/myf_666/article/details/128167392
int16_t x = 0;int16_t y = y_radius;const int16_t y_radius_square = SQUARE(y_radius);const int16_t x_radius_square = SQUARE(x_radius);
// Initial decision variable for the first region of the ellipsefloat d1 = y_radius_square + x_radius_square * (-y_radius + 0.5);
// Draw initial points on the ellipse (4 points due to symmetry)CCGraphic_Point point;DRAW_OFFSET_POINT(x, y);DRAW_OFFSET_POINT(-x, -y);DRAW_OFFSET_POINT(-x, y);DRAW_OFFSET_POINT(x, -y);
// Draw the middle part of the ellipse (first region)while (y_radius_square * (x + 1) < x_radius_square * (y - 0.5)) {if (d1 <= 0) {  // Next point is to the east of the current pointd1 += y_radius_square * (2 * x + 3);} else {  // Next point is southeast of the current pointd1 += y_radius_square * (2 * x + 3) + x_radius_square * (-2 * y + 2);y--;}x++;
// Draw ellipse arc for each point in the current regionDRAW_OFFSET_POINT(x, y);DRAW_OFFSET_POINT(-x, -y);DRAW_OFFSET_POINT(-x, y);DRAW_OFFSET_POINT(x, -y);}
// Draw the two sides of the ellipse (second region)float d2 = SQUARE(y_radius * (x + 0.5)) + SQUARE(x_radius * (y - 1)) - x_radius_square * y_radius_square;
while (y > 0) {if (d2 <= 0) {  // Next point is to the east of the current pointd2 += y_radius_square * (2 * x + 2) + x_radius_square * (-2 * y + 3);x++;} else {  // Next point is southeast of the current pointd2 += x_radius_square * (-2 * y + 3);}y--;
// Draw ellipse arc for each point on the sidesDRAW_OFFSET_POINT(x, y);DRAW_OFFSET_POINT(-x, -y);DRAW_OFFSET_POINT(-x, y);DRAW_OFFSET_POINT(x, -y);}
}

void CCGraphic_drawfilled_ellipse(CCDeviceHandler* handler,CCGraphic_Ellipse* ellipse
)
{const int16_t x_radius = ellipse->X_Radius;const int16_t y_radius = ellipse->Y_Radius;
// Bresenham's Ellipse Algorithm to avoid costly floating point calculations// Reference: https://blog.csdn.net/myf_666/article/details/128167392
int16_t x = 0;int16_t y = y_radius;const int16_t y_radius_square = SQUARE(y_radius);const int16_t x_radius_square = SQUARE(x_radius);
// Initial decision variable for the first region of the ellipsefloat d1 = y_radius_square + x_radius_square * (-y_radius + 0.5);CCGraphic_Point point;// Fill the ellipse by drawing vertical lines in the specified range (filled area)for (int16_t j = -y; j < y; j++) {// Draw vertical lines to fill the area of the ellipseDRAW_OFFSET_POINT(0, j);DRAW_OFFSET_POINT(0, j);}
// Draw initial points on the ellipse (4 points due to symmetry)DRAW_OFFSET_POINT(x, y);DRAW_OFFSET_POINT(-x, -y);DRAW_OFFSET_POINT(-x, y);DRAW_OFFSET_POINT(x, -y);
// Draw the middle part of the ellipse (first region)while (y_radius_square * (x + 1) < x_radius_square * (y - 0.5)) {if (d1 <= 0) {  // Next point is to the east of the current pointd1 += y_radius_square * (2 * x + 3);} else {  // Next point is southeast of the current pointd1 += y_radius_square * (2 * x + 3) + x_radius_square * (-2 * y + 2);y--;}x++;
// Fill the ellipse by drawing vertical lines in the current rangefor (int16_t j = -y; j < y; j++) {DRAW_OFFSET_POINT(x, j);DRAW_OFFSET_POINT(-x, j);}
// Draw ellipse arc for each point in the current regionDRAW_OFFSET_POINT(x, y);DRAW_OFFSET_POINT(-x, -y);DRAW_OFFSET_POINT(-x, y);DRAW_OFFSET_POINT(x, -y);}
// Draw the two sides of the ellipse (second region)float d2 = SQUARE(y_radius * (x + 0.5)) + SQUARE(x_radius * (y - 1)) - x_radius_square * y_radius_square;
while (y > 0) {if (d2 <= 0) {  // Next point is to the east of the current pointd2 += y_radius_square * (2 * x + 2) + x_radius_square * (-2 * y + 3);x++;} else {  // Next point is southeast of the current pointd2 += x_radius_square * (-2 * y + 3);}y--;
// Fill the ellipse by drawing vertical lines in the current rangefor (int16_t j = -y; j < y; j++) {DRAW_OFFSET_POINT(x, j);DRAW_OFFSET_POINT(-x, j);}
// Draw ellipse arc for each point on the sidesDRAW_OFFSET_POINT(x, y);DRAW_OFFSET_POINT(-x, -y);DRAW_OFFSET_POINT(-x, y);DRAW_OFFSET_POINT(x, -y);}
}

#undef DRAW_OFFSET_POINT
#undef SQUARE

#include "Graphic/base/CCGraphic_Circle/CCGraphic_Circle.h"
#include "Graphic/CCGraphic_device_adapter.h"
#include "Graphic/common/CCGraphic_Utils.h"

void CCGraphic_init_circle(CCGraphic_Circle* circle, CCGraphic_Point c, uint8_t radius)
{circle->center = c;circle->radius = radius;
}

#define DRAW_OFFSET_POINT(point, offsetx, offsety) \do { \point.x = circle->center.x + (offsetx); \point.y = circle->center.y + (offsety); \CCGraphic_draw_point(handler, &point);}while(0)

void CCGraphic_draw_circle(CCDeviceHandler* handler, CCGraphic_Circle* circle)
{/*参考文档：https://www.cs.montana.edu/courses/spring2009/425/dslectures/Bresenham.pdf*//*参考教程：https://www.bilibili.com/video/BV1VM4y1u7wJ*/CCGraphic_Point p;int16_t d = 1 - circle->radius;int16_t x = 0;int16_t y = circle->radius;
DRAW_OFFSET_POINT(p, x, y);DRAW_OFFSET_POINT(p, -x, -y);DRAW_OFFSET_POINT(p, y, x);DRAW_OFFSET_POINT(p, -y, -x);
while(x < y){x++;if(d < 0){ d += 2 * x + 1;}else {y--; d += 2 * (x - y) + 1;}DRAW_OFFSET_POINT(p, x, y);DRAW_OFFSET_POINT(p, y, x);DRAW_OFFSET_POINT(p, -x, -y);DRAW_OFFSET_POINT(p, -y, -x);DRAW_OFFSET_POINT(p, x, -y);DRAW_OFFSET_POINT(p, y, -x);DRAW_OFFSET_POINT(p, -x, y);DRAW_OFFSET_POINT(p, -y, x);            }
}

void CCGraphic_drawfilled_circle(CCDeviceHandler* handler, CCGraphic_Circle* circle)
{CCGraphic_Point p;int16_t d = 1 - circle->radius;int16_t x = 0;int16_t y = circle->radius;
DRAW_OFFSET_POINT(p, x, y);DRAW_OFFSET_POINT(p, -x, -y);DRAW_OFFSET_POINT(p, y, x);DRAW_OFFSET_POINT(p, -y, -x);
for(int16_t i = -y; i < y; i++)DRAW_OFFSET_POINT(p, 0, i);
while(x < y){x++;if(d < 0){ d += 2 * x + 1;}else {y--; d += 2 * (x - y) + 1;}DRAW_OFFSET_POINT(p, x, y);DRAW_OFFSET_POINT(p, y, x);DRAW_OFFSET_POINT(p, -x, -y);DRAW_OFFSET_POINT(p, -y, -x);DRAW_OFFSET_POINT(p, x, -y);DRAW_OFFSET_POINT(p, y, -x);DRAW_OFFSET_POINT(p, -x, y);DRAW_OFFSET_POINT(p, -y, x);   for(int16_t i = -y; i < y; i++){DRAW_OFFSET_POINT(p, x, i);DRAW_OFFSET_POINT(p, -x, i);  }for(int16_t i = -x; i < x; i++){DRAW_OFFSET_POINT(p, y, i);DRAW_OFFSET_POINT(p, -y, i);  }              }    
}

#undef DRAW_OFFSET_POINT

现在我们可以上测试了

继续我们的测试

#include "Test/GraphicTest/graphic_test.h"
#include "Graphic/base/CCGraphic_Point/CCGraphic_Point.h"
#include "Graphic/base/CCGraphic_Line/CCGraphic_Line.h"
#include "Graphic/base/CCGraphic_Circle/CCGraphic_Circle.h"
#include "Graphic/base/CCGraphic_Rectangle/CCGraphic_Rectangle.h"
#include "Graphic/base/CCGraphic_Triangle/CCGraphic_Triangle.h"
#include "Graphic/base/CCGraphic_Ellipse/CCGraphic_Ellipse.h"
#include "Graphic/base/CCGraphic_Arc/CCGraphic_Arc.h"

void on_test_draw_points(CCDeviceHandler* handle)
{CCGraphic_Point point;CCGraphic_init_point(&point, 0, 0);for(uint8_t i = 0; i < 20; i++){point.x = i;point.y = i * 2;CCGraphic_draw_point(handle, &point);}handle->operations.update_device_function(handle);
}

void on_test_draw_line(CCDeviceHandler* handle)
{CCGraphic_Line  l;CCGraphic_Point pleft;CCGraphic_Point pright;// try verticalpleft.x     = 5;pleft.y     = 0;pright.x    = pleft.x;pright.y    = 63;
CCGraphic_init_line(&l, pleft, pright);CCGraphic_draw_line(handle, &l);
// try horizontalpleft.x     = 0;pleft.y     = 5;pright.x    = 120;pright.y    = pleft.y;
CCGraphic_init_line(&l, pleft, pright);CCGraphic_draw_line(handle, &l);
// try differentpleft.x     = 0;pleft.y     = 10;pright.x    = 105;pright.y    = 63;
CCGraphic_init_line(&l, pleft, pright);CCGraphic_draw_line(handle, &l);handle->operations.update_device_function(handle);
}

void on_test_draw_circle(CCDeviceHandler* handle)
{CCGraphic_Circle c;CCGraphic_Point p;p.x = 64;p.y = 32;CCGraphic_init_circle(&c, p, 10);CCGraphic_drawfilled_circle(handle, &c);
p.x = 10;p.y = 32;CCGraphic_init_circle(&c, p, 5);CCGraphic_draw_circle(handle, &c);handle->operations.update_device_function(handle);
}

void on_test_draw_rectangle(CCDeviceHandler* handle)
{CCGraphic_Rectangle rect;CCGraphic_Point     tl;CCGraphic_Point     br;
tl.x = 5;tl.y = 5;
br.x = 20;br.y = 20;
CCGraphic_init_rectangle(&rect, tl, br);CCGraphic_draw_rectangle(handle, &rect);
tl.x = 21;tl.y = 21;
br.x = 50;br.y = 50;    CCGraphic_init_rectangle(&rect, tl, br);CCGraphic_drawfilled_rectangle(handle, &rect);handle->operations.update_device_function(handle);
}

void on_test_draw_triangle(CCDeviceHandler* handle)
{CCGraphic_Triangle  triangle;CCGraphic_Point     p1;CCGraphic_Point     p2;CCGraphic_Point     p3;
p1.x = 10;p1.y = 10;
p2.x = 15;p2.y = 5;
p3.x = 80;p3.y = 40;
CCGraphic_init_triangle(&triangle, p1, p3, p2);CCGraphic_drawfilled_triangle(handle, &triangle);handle->operations.update_device_function(handle);
}

void on_test_draw_ellipse(CCDeviceHandler* handle)
{CCGraphic_Ellipse ellipse;CCGraphic_Point p;p.x = 20;p.y = 32;
CCGraphic_init_ellipse(&ellipse, p, 10, 30);CCGraphic_draw_ellipse(handle, &ellipse);
p.x = 80;p.y = 32;CCGraphic_init_ellipse(&ellipse, p, 40, 30);CCGraphic_drawfilled_ellipse(handle, &ellipse);handle->operations.update_device_function(handle);
}

void on_test_draw_arc(CCDeviceHandler* handle)
{CCGraphic_Arc arc;CCGraphic_Point p;p.x = 64;p.y = 32;CCGraphic_init_CCGraphic_Arc(&arc, p, 40, -20, 40);CCGraphic_draw_arc(handle, &arc);handle->operations.update_device_function(handle);
}

在main.c中就可以这样调用

    on_test_draw_points(handler);HAL_Delay(1000);on_test_draw_line(handler);HAL_Delay(1000);on_test_draw_circle(handler);HAL_Delay(1000);on_test_draw_rectangle(handler);HAL_Delay(1000);on_test_draw_triangle(handler);HAL_Delay(1000);on_test_draw_ellipse(handler);HAL_Delay(1000);on_test_draw_arc(handler);

完整测试视频

目录导览

总览

协议层封装

OLED设备封装

绘图设备抽象

基础图形库封装

基础组件实现

动态菜单组件实现

基础图形库的抽象

抽象图形

抽象点

设计我们的抽象

实现我们的抽象

测试

抽象线

设计我们的抽象

实现我们的抽象

绘制垂直的和水平的线

使用Bresenham算法完成任意斜率的绘制

绘制三角形和矩形

矩形

三角形

实现

绘制圆，圆弧和椭圆

继续我们的测试

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