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fix: 修复 putimage 系列函数源图像区域参数填写不正确时会发生崩溃的问题
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@yixy-only
yixy-only committed Jul 2, 2024
1 parent 5e50e48 commit a385b13
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Showing 4 changed files with 374 additions and 52 deletions.
12 changes: 12 additions & 0 deletions src/ege_math.h
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Original file line number Diff line number Diff line change
Expand Up @@ -45,4 +45,16 @@ T clamp(T value, T min, T max)
return (value < min) ? min : ((value > max) ? max : value);
}

// Overflow 判断
inline bool sumIsOverflow(int a, int b)
{
return (a > 0) && (b > 0) && (b > (INT_MAX - a));
}

// Underflow 判断
inline bool sumIsUnderflow(int a, int b)
{
return (a < 0) && (b < 0) && (b < (INT_MIN - a));
}

} // namespace ege
174 changes: 128 additions & 46 deletions src/image.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,6 @@
#include "ege_head.h"
#include "ege_common.h"
#include "ege_dllimport.h"

// #ifdef _ITERATOR_DEBUG_LEVEL
// #undef _ITERATOR_DEBUG_LEVEL
// #endif
Expand All @@ -27,6 +26,7 @@


#include <math.h>
#include <limits.h>

namespace ege
{
Expand Down Expand Up @@ -809,58 +809,121 @@ void IMAGE::putimage(PIMAGE imgDest, int xDest, int yDest, int widthDest, int he
CONVERT_IMAGE_END;
}

/**
* @brief 对两个区域进行裁剪(目标区域大小和源区域相同)
*
* @param[in,out] dest 目标位置
* @param[in,out] src 源区域
* @param[in] destClip 目标裁剪区域(需保证边界和宽高在 int 范围内)
* @param[in] srcClip 源裁剪区域(需保证边界和宽高在 int 范围内)
*
* @return true 结果区域不为空
* @return false 结果区域为空
*/
static bool fixRect(Point& dest, Rect& src, const Rect& destClip, const Rect& srcClip)
{
if ((dest.x < destClip.right()) && dest.y < destClip.bottom()) {
Rect srcIntersection = intersect(src, srcClip);

if (srcIntersection.isValid()) {
/* 偏移量，满足 >= 0 关系*/
int srcOffsetX = srcIntersection.x - src.x;
int srcOffsetY = srcIntersection.y - src.y;

/* 溢出校验 */
if ((dest.x > INT_MAX - srcOffsetX) || (dest.y > INT_MAX - srcOffsetY)) {
src.setEmpty();
return false;
}

dest.offset(srcOffsetX, srcOffsetY);
Rect destRect(dest, srcIntersection.size());

/* 超出边界则进行裁剪 */
if (destRect.x > INT_MAX - destRect.width) {
destRect.width = INT_MAX - destRect.x;
}

if (destRect.y > INT_MAX - destRect.height) {
destRect.height = INT_MAX - destRect.y;
}

Rect destIntersection = intersect(destRect, destClip);

if (destIntersection.isValid()) {
srcIntersection.setSize(destIntersection.size());
int xOffset = destIntersection.x - dest.x;
int yOffset = destIntersection.y - dest.y;
srcIntersection.offset(xOffset, yOffset);

src = srcIntersection;
dest = destIntersection.topLeft();
return true;
}
}
}

// 经裁剪后区域为空
src.setEmpty();
return false;
}

/* private function */
static void fix_rect_1size(PCIMAGE imgDest, PCIMAGE imgSrc, int* xDest, int* yDest,
int* xSrc, int* ySrc, int* widthSrc, int* heightSrc)
int* xSrc, int* ySrc, int* width, int* height)
{
/* 区域无效 */
if (*xSrc >= imgSrc->m_width || (*ySrc >= imgSrc->m_height)) {
*width = *height = 0;
return;
}

/* prepare viewport region and carry out coordinate transformation */
struct viewporttype _vpt = imgDest->m_vpt;
*xDest += _vpt.left;
*yDest += _vpt.top;
/* default value proc */
if (*widthSrc == 0) {
*widthSrc = imgSrc->m_width;
*heightSrc = imgSrc->m_height;
}
/* fix src rect */
if (*widthSrc > imgSrc->m_width) {
*widthSrc -= *widthSrc - imgSrc->m_width;
*widthSrc = imgSrc->m_width;
}
if (*heightSrc > imgSrc->m_height) {
*heightSrc -= *heightSrc - imgSrc->m_height;
*heightSrc = imgSrc->m_height;
}
if (*xSrc < 0) {
*widthSrc += *xSrc;
*xDest += *xSrc;
*xSrc = 0;
}
if (*ySrc < 0) {
*heightSrc += *ySrc;
*yDest += *ySrc;
*ySrc = 0;
}
/* fix dest vpt rect */
if (*xDest < _vpt.left) {
int dx = _vpt.left - *xDest;
*xDest += dx;
*xSrc += dx;
*widthSrc -= dx;
struct viewporttype vpt = imgDest->m_vpt;
*xDest += vpt.left;
*yDest += vpt.top;

int left = (*xSrc < 0) ? 0 : *xSrc;
int top = (*ySrc < 0) ? 0 : *ySrc;

int right = imgSrc->m_width, bottom = imgSrc->m_height;;
if (*width > 0) {
right = sumIsOverflow(*xSrc, *width) ? INT_MAX: (*xSrc + *width);
}
if (*yDest < _vpt.top) {
int dy = _vpt.top - *yDest;
*yDest += dy;
*ySrc += dy;
*heightSrc -= dy;

if (*height > 0) {
bottom = sumIsOverflow(*ySrc, *height) ? INT_MAX : (*ySrc + *height);
}
if (*xDest + *widthSrc > _vpt.right) {
int dx = *xDest + *widthSrc - _vpt.right;
*widthSrc -= dx;

/* 偏移量，范围: [0, INT_MAX+1] */
unsigned int xOffset = left - *xSrc;
unsigned int yOffset = top - *ySrc;

Point dstPos(*xDest + vpt.left, *yDest + vpt.top);

if ((dstPos.x > (int)(INT_MAX - xOffset)) || (dstPos.y > (int)(INT_MAX - yOffset))) {
*width = *height = 0;
return;
} else {
dstPos.offset((int)xOffset, (int)yOffset);
}
if (*yDest + *heightSrc > _vpt.bottom) {
int dy = *yDest + *heightSrc - _vpt.bottom;
*heightSrc -= dy;

Rect srcRect(Point(left, top), Point(right, bottom));
// 设定裁剪区域，源图像
Rect dstClip(Point(vpt.left, vpt.top), Point(vpt.right, vpt.bottom));
Rect srcClip(Point(0, 0), Point(imgSrc->m_width, imgSrc->m_height));

bool isValid = fixRect(dstPos, srcRect, dstClip, srcClip);
if (!isValid) {
*width = *height = 0;
return;
} else {
*xDest = dstPos.x;
*yDest = dstPos.y;
*xSrc = srcRect.x;
*ySrc = srcRect.y;
*width = srcRect.width;
*height = srcRect.height;
}
}

Expand All @@ -883,6 +946,10 @@ int IMAGE::putimage_transparent(PIMAGE imgDest, // handle to dest
DWORD * pdp, *psp, cr;
// fix rect
fix_rect_1size(img, imgSrc, &xDest, &yDest, &xSrc, &ySrc, &widthSrc, &heightSrc);

if ((widthSrc == 0) || (heightSrc == 0))
return;

// draw
pdp = img->m_pBuffer + yDest * img->m_width + xDest;
psp = imgSrc->m_pBuffer + ySrc * imgSrc->m_width + xSrc;
Expand Down Expand Up @@ -922,6 +989,9 @@ int IMAGE::putimage_alphablend(PIMAGE imgDest, // handle to dest
DWORD * pdp, *psp;
// fix rect
fix_rect_1size(img, imgSrc, &xDest, &yDest, &xSrc, &ySrc, &widthSrc, &heightSrc);

if ((widthSrc == 0) || (heightSrc == 0))
return;
// draw
pdp = img->m_pBuffer + yDest * img->m_width + xDest;
psp = imgSrc->m_pBuffer + ySrc * imgSrc->m_width + xSrc;
Expand Down Expand Up @@ -961,6 +1031,9 @@ int IMAGE::putimage_alphatransparent(PIMAGE imgDest, // handle to dest
DWORD * pdp, *psp, cr;
// fix rect
fix_rect_1size(img, imgSrc, &xDest, &yDest, &xSrc, &ySrc, &widthSrc, &heightSrc);

if ((widthSrc == 0) || (heightSrc == 0))
return;
// draw
pdp = img->m_pBuffer + yDest * img->m_width + xDest;
psp = imgSrc->m_pBuffer + ySrc * imgSrc->m_width + xSrc;
Expand Down Expand Up @@ -1000,6 +1073,9 @@ int IMAGE::putimage_withalpha(PIMAGE imgDest, // handle to dest
DWORD * pdp, *psp;
// fix rect
fix_rect_1size(img, imgSrc, &xDest, &yDest, &xSrc, &ySrc, &widthSrc, &heightSrc);

if ((widthSrc == 0) || (heightSrc == 0))
return;
// draw
pdp = img->m_pBuffer + yDest * img->m_width + xDest;
psp = imgSrc->m_pBuffer + ySrc * imgSrc->m_width + xSrc;
Expand Down Expand Up @@ -1043,6 +1119,9 @@ int IMAGE::putimage_withalpha(PIMAGE imgDest, // handle to dest
BLENDFUNCTION bf;
// fix rect
fix_rect_1size(img, imgSrc, &xDest, &yDest, &xSrc, &ySrc, &widthSrc, &heightSrc);

if ((widthSrc == 0) || (heightSrc == 0))
return;
// premultiply alpha channel
pdp = alphaSrc->m_pBuffer;
psp = imgSrc->m_pBuffer + ySrc * imgSrc->m_width + xSrc;
Expand Down Expand Up @@ -1133,6 +1212,9 @@ int IMAGE::putimage_alphafilter(PIMAGE imgDest, // handle to dest
// DWORD sa = alpha + 1, da = 0xFF - alpha;
// fix rect
fix_rect_1size(img, imgSrc, &xDest, &yDest, &xSrc, &ySrc, &widthSrc, &heightSrc);

if ((widthSrc == 0) || (heightSrc == 0))
return;
// draw
pdp = img->m_pBuffer + yDest * img->m_width + xDest;
psp = imgSrc->m_pBuffer + ySrc * imgSrc->m_width + xSrc;
Expand Down
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