代码中，先把字型矩阵转换为bit，再进行旋转。关键有几点：
- 计算数组大小。
size = (w+7) * (h+7) / 8;
- 正确旋转的算法。这个通过byte旋转代码得到。参考：
https://quantum6.blog.csdn.net/article/details/110794038
- bit坐标转换。代码是这样的：
int srcPos = (offset + x); int srcPosByte = srcPos / 8; int srcPosBit = srcPos % 8; int value = (pBuffer[srcPosByte] & (0x01 << srcPosBit)) != 0 ? 1 : 0; int dstPosByte = i / 8; int dstPosBite = i % 8; pRotated[dstPosByte] |= (value << dstPosBite);
全部源码：
看到这么整齐的源码，肯定是本人所写。如此漂亮，阁下应该学习初中。
#include <stdio.h> #include <stdlib.h> #include <wchar.h> #include <ft2build.h> #include <freetype/freetype.h> #include FT_FREETYPE_H #define FONT_FILE "/home/uos/font/simsun.ttc" static void dumpByte(char* pBuffer, int w, int h) { int i=0; int j=0; //printf("w=%d, h=%d\n", w, h); for (i=0; i<h; i++) { printf("|"); for (j=0; j<w; j++) { printf((pBuffer[i * w + j]) ? "1" : " "); } printf("|\n"); } } static void dumpFontBmp(FT_Bitmap* pBmp) { int w = pBmp->width; int h = pBmp->rows; dumpByte(pBmp->buffer, w, h); } static char* byteToBit(char* pBuffer, int w, int h) { int i=0; int j=0; int size = (w+7) * (h+7) / 8; char* bits = (char*)malloc(size); memset(bits, 0, size); for (i=0; i<h; i++) { for (j=0; j<w; j++) { int srcPos = (i * w + j); int srcPosByte = srcPos / 8; int srcPosBit = srcPos % 8; bits[srcPosByte] |= (pBuffer[i * w + j] == 0 ? 0 : (0x01 << srcPosBit)); } } return bits; } static void dumpBit(char* pBuffer, int w, int h) { int i=0; int j=0; printf("w=%d, h=%d\n", w, h); for (i=0; i<h; i++) { printf("|"); for (j=0; j<w; j++) { int srcPos = (i * w + j); int posByte = srcPos / 8; int posBit = srcPos % 8; int bitValue = (pBuffer[posByte] & (0x01 << posBit)) != 0 ? 1 : 0; printf(bitValue ? "1" : " "); } printf("|\n"); } } static char* rotate_90(char* pBuffer, int w, int h) { int i=0; char* pRotated; int size; int offset=0; size = (w+7) * (h+7) / 8; pRotated = (char*)malloc(size); memset(pRotated, 0, size); int startPos = (h - 1) * w; i = 0; for (int x = 0; x < w; x++) { int offset = startPos; for (int y = h - 1; y >= 0; y--) { int srcPos = (offset + x); int srcPosByte = srcPos / 8; int srcPosBit = srcPos % 8; int srcBitValue = (pBuffer[srcPosByte] & (0x01 << srcPosBit)) != 0 ? 1 : 0; int dstPosByte = (i)/8; int dstPosBit = (i)%8; pRotated[dstPosByte] |= (srcBitValue << dstPosBit); i++; offset -= w; } } dumpBit(pRotated, h, w); return pRotated; } static char* rotate_270(char* pBuffer, int w, int h) { int i=0; char* pRotated; int size; int offset=0; size = (w+7) * (h+7)/8; pRotated = (char*)malloc(size); memset(pRotated, 0, size); i = 0; for (int x = w-1; x >= 0; x--) { int offset = 0; for (int y = 0; y < h; y++) { int srcPos = (offset + x); int srcPosByte = srcPos / 8; int srcPosBit = srcPos % 8; int srcBitValue = (pBuffer[srcPosByte] & (0x01 << srcPosBit)) != 0 ? 1 : 0; int dstPosByte = i / 8; int dstPosBit = i % 8; pRotated[dstPosByte] |= (srcBitValue << dstPosBit); i++; offset += w; } } dumpBit(pRotated, h, w); return pRotated; } int main() { FT_Library m_pFTLib; FT_Face m_pFTFace; wchar_t chinese_char = L'泰'; FT_Error result = FT_Init_FreeType(&m_pFTLib); if(FT_New_Face(m_pFTLib, FONT_FILE, 0, &m_pFTFace)) { printf("FT_New_Face error!\n"); return -1; } //FT_ENCODING_GB2312, FT_ENCODING_UNICODE FT_Select_Charmap(m_pFTFace, FT_ENCODING_UNICODE); FT_Set_Char_Size(m_pFTFace, 0, 12<<6, 200, 200); result = FT_Load_Glyph(m_pFTFace, FT_Get_Char_Index(m_pFTFace, chinese_char), FT_LOAD_DEFAULT); // 第二个参数为渲染模式 result = FT_Render_Glyph(m_pFTFace->glyph, FT_RENDER_MODE_NORMAL); printf("result=%d\n", result); FT_Bitmap* pBmp = &(m_pFTFace->glyph->bitmap); //dumpFontBmp(pBmp); int w = pBmp->width; int h = pBmp->rows; char* bits = byteToBit(m_pFTFace->glyph->bitmap.buffer, w, h); dumpBit(bits, w, h); rotate_90( bits, w, h); rotate_270(bits, w, h); return 0; }
