Raylib 坐标系

draftx 符号调整为正数

发现采样坐标系原点0，0 在左上角，正方向 右，下

绘制坐标系 原点0，0 在左下角，正方向 右，上

拖拽可得

 

 

#include <raylib.h>
// 重整原因：解决新函数放大缩小之下，raylib 的网格采样部分，选择数组的一部分刷新倒缓冲区里
// 从直接建立缓冲区，到先在数组里进行移动，然后再设置检查缓冲区


int main() {
int **map;
map = new int*[250];
for (int i = 0; i < 250; i++) {
map[i] = new int[250];
}
for (int i = 0; i < 250; i++) {
for (int j = 0; j < 250; j++) {
//测试数据，渐变 25改105 柔和
map[i][j] = (j + i) % 105;
}
}

//初始化窗口
InitWindow(1750, 1050, "test for location");
//设置GPU可以操作的画布,一定要再初始化窗口之后才行，实际上是OpenGL的上下文，或者说默认环境设置
RenderTexture2D mesh = LoadRenderTexture(750 + 30 * 2, 750 + 30 * 2);
//设置帧率
SetTargetFPS(160);
//设置默认绘制到mesh
BeginTextureMode(mesh);
for (int i = 0; i < 25; i++) {
for (int j = 0; j < 25; j++) {
//绘制矩形,原点(0,0)在左下角,现在是从左下角一行一行往上绘制
if (i == 0 || j == 0 || i == 24 || j == 24) {
DrawRectangle(j * 30, i * 30, 30, 30, {0, 255, 255, 255});
} else  {
DrawRectangle(j * 30, i * 30, 30, 30, {map[i][j] * 5 % 255, map[i][j] * 5 % 255, 255, 255});
}
}
}
//取消绘制的GPU画布
EndTextureMode();
//设置默认绘制到桌面
BeginDrawing();
//黑色覆盖全部屏幕
ClearBackground(BLACK);
DrawTexturePro(mesh.texture, {0, 0, 750, 750}, {0, 0, 750, 750}, {0, 0}, 0, WHITE);
//结束绘制的桌面
EndDrawing();

int mousex;
int mousey;
mousex = 0;
mousey = 0;
float camerasize;
camerasize = 1;
//拖拽
int draftflag;
int draftx;
int drafty;
int gamex;
int gamey;
//记录长按时，鼠标按下去的位置，减出长按拖拽距离
int oldx;
int oldy;
draftflag = 0;
draftx = 0;
drafty = 0;
gamex = 0;
gamey = 0;

//记录bkmeshmap 网格,用于出界刷新
int bkmeshmapi;
int bkmeshmapj;
int bkmeshmapmaxi;
int bkmeshmapmaxj;
bkmeshmapi = 0;
bkmeshmapi = 0;
bkmeshmapmaxi = 25 + 2;
bkmeshmapmaxj = 25 + 2;

//拖拽边界
int limitright;
int limitleft;
int limittop;
int limitbottom;

//坐标系变化，现在是在底部进行，左下角是0，0原点
limitright = 25 * 30 + 30 * 2;
limitleft = 0;
limittop = 25 * 30 + 30 * 2;
limitbottom = 0;


//这里开始主循环
while (!WindowShouldClose()) {
//注意是pressed 不是 Down
if (IsMouseButtonPressed(MOUSE_BUTTON_RIGHT)) {
draftflag = 1;
oldx = GetMouseX();
oldy = GetMouseY();
}
if (draftflag == 1) {
mousex = GetMouseX();
mousey = GetMouseY();
draftx = gamex - (mousex - oldx) / camerasize;
drafty = gamey - (mousey - oldy) / camerasize;
}
if (IsMouseButtonUp(MOUSE_BUTTON_RIGHT)) {
draftflag = 0;
oldx = 0;
oldy = 0;
gamex = draftx;
gamey = drafty;
}


if (draftx < limitleft && draftx > 30) {
bkmeshmapj - 1;
limitleft -= 30;
} else if (draftx > limitright + bkmeshmapi * 30 && draftx < 250 * 30 - 750 - 30) {
bkmeshmapj + 1;
limitright += 30;
}

if (drafty < limitbottom && drafty > 30) {
bkmeshmapj - 1;
limittop -= 30;
} else if (draftx > limittop && drafty < 250 * 30 - 750 - 30) {
bkmeshmapj + 1;
limitbottom += 30;
}


//设置默认绘制到mesh
BeginTextureMode(mesh);
for (int i = 0; i < 25 + 2; i++) {
for (int j = 0; j < 25 + 2; j++) {
//绘制矩形,原点(0,0)在左下角,现在是从左下角一行一行往上绘制
if (map[i][j] == 266) {
DrawRectangle(j * 30, i * 30, 30, 30, {255, 0, 255, 255});
} else {
DrawRectangle(j * 30, i * 30, 30, 30, {map[i + bkmeshmapi][j + bkmeshmapj] * 5 % 255, map[i + bkmeshmapi][j + bkmeshmapj] * 5 % 255, 255, 255});
}
DrawRectangle(0, 0, 50, 50, {154, 154, 154, 255});
//绘制坐标系是左下角0，0）y正方向向上
}
}
//取消绘制的GPU画布
EndTextureMode();
//设置默认绘制到桌面
BeginDrawing();
//黑色覆盖全部屏幕
ClearBackground(BLACK);
//采样坐标系是左上角0，0，y轴正方向向下
DrawTexturePro(mesh.texture, {draftx - bkmeshmapi * 30, drafty - bkmeshmapj * 30, 750 / camerasize, 750 / camerasize}, {0, 0, 750, 750}, {0, 0}, 0, WHITE);

DrawText(TextFormat("mouseV1 %.0f,%.0f", GetMousePosition().x, GetMousePosition().y), 35, 12, 30, BLUE);
DrawText(TextFormat("mouseV2 %.0f,%.0f", GetMousePosition().x, 750 - GetMousePosition().y), 35, 62, 30, BLUE);

DrawText(TextFormat("draftxyV2 %d,%d", draftx, drafty), 35, 152, 30, RED);
DrawText(TextFormat("camerasize %f", camerasize), 35, 192, 30, BLACK);
//结束绘制的桌面
EndDrawing();
}
}

原文地址：https://blog.csdn.net/a1309602336/article/details/140234325

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