aboutsummaryrefslogtreecommitdiff
path: root/smelt/sdl/CxImage/xmemfile.cpp
blob: f23589992f4d8e6ff4700192cf22121ffea33ce3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
#include "xmemfile.h"

//////////////////////////////////////////////////////////
CxMemFile::CxMemFile(uint8_t* pBuffer, uint32_t size)
{
	m_pBuffer = pBuffer;
	m_Position = 0;
	m_Size = m_Edge = size;
	m_bFreeOnClose = (bool)(pBuffer==0);
	m_bEOF = false;
}
//////////////////////////////////////////////////////////
CxMemFile::~CxMemFile()
{
	Close();
}
//////////////////////////////////////////////////////////
bool CxMemFile::Close()
{
	if ( (m_pBuffer) && (m_bFreeOnClose) ){
		free(m_pBuffer);
		m_pBuffer = NULL;
		m_Size = 0;
	}
	return true;
}
//////////////////////////////////////////////////////////
bool CxMemFile::Open()
{
	if (m_pBuffer) return false;	// Can't re-open without closing first

	m_Position = m_Size = m_Edge = 0;
	m_pBuffer=(uint8_t*)malloc(1);
	m_bFreeOnClose = true;

	return (m_pBuffer!=0);
}
//////////////////////////////////////////////////////////
uint8_t* CxMemFile::GetBuffer(bool bDetachBuffer)
{
	//can only detach, avoid inadvertantly attaching to
	// memory that may not be ours [Jason De Arte]
	if( bDetachBuffer )
		m_bFreeOnClose = false;
	return m_pBuffer;
}
//////////////////////////////////////////////////////////
size_t CxMemFile::Read(void *buffer, size_t size, size_t count)
{
	if (buffer==NULL) return 0;

	if (m_pBuffer==NULL) return 0;
	if (m_Position >= (int32_t)m_Size){
		m_bEOF = true;
		return 0;
	}

	int32_t nCount = (int32_t)(count*size);
	if (nCount == 0) return 0;

	int32_t nRead;
	if (m_Position + nCount > (int32_t)m_Size){
		m_bEOF = true;
		nRead = (m_Size - m_Position);
	} else
		nRead = nCount;

	memcpy(buffer, m_pBuffer + m_Position, nRead);
	m_Position += nRead;

	return (size_t)(nRead/size);
}
//////////////////////////////////////////////////////////
size_t CxMemFile::Write(const void *buffer, size_t size, size_t count)
{
	m_bEOF = false;
	if (m_pBuffer==NULL) return 0;
	if (buffer==NULL) return 0;

	int32_t nCount = (int32_t)(count*size);
	if (nCount == 0) return 0;

	if (m_Position + nCount > m_Edge){
		if (!Alloc(m_Position + nCount)){
			return false;
		}
	}

	memcpy(m_pBuffer + m_Position, buffer, nCount);

	m_Position += nCount;

	if (m_Position > (int32_t)m_Size) m_Size = m_Position;
	
	return count;
}
//////////////////////////////////////////////////////////
bool CxMemFile::Seek(int32_t offset, int32_t origin)
{
	m_bEOF = false;
	if (m_pBuffer==NULL) return false;
	int32_t lNewPos = m_Position;

	if (origin == SEEK_SET)		 lNewPos = offset;
	else if (origin == SEEK_CUR) lNewPos += offset;
	else if (origin == SEEK_END) lNewPos = m_Size + offset;
	else return false;

	if (lNewPos < 0) lNewPos = 0;

	m_Position = lNewPos;
	return true;
}
//////////////////////////////////////////////////////////
int32_t CxMemFile::Tell()
{
	if (m_pBuffer==NULL) return -1;
	return m_Position;
}
//////////////////////////////////////////////////////////
int32_t CxMemFile::Size()
{
	if (m_pBuffer==NULL) return -1;
	return m_Size;
}
//////////////////////////////////////////////////////////
bool CxMemFile::Flush()
{
	if (m_pBuffer==NULL) return false;
	return true;
}
//////////////////////////////////////////////////////////
bool CxMemFile::Eof()
{
	if (m_pBuffer==NULL) return true;
	return m_bEOF;
}
//////////////////////////////////////////////////////////
int32_t CxMemFile::Error()
{
	if (m_pBuffer==NULL) return -1;
	return (m_Position > (int32_t)m_Size);
}
//////////////////////////////////////////////////////////
bool CxMemFile::PutC(uint8_t c)
{
	m_bEOF = false;
	if (m_pBuffer==NULL) return false;

	if (m_Position >= m_Edge){
		if (!Alloc(m_Position + 1)){
			return false;
		}
	}

	m_pBuffer[m_Position++] = c;

	if (m_Position > (int32_t)m_Size) m_Size = m_Position;
	
	return true;
}
//////////////////////////////////////////////////////////
int32_t CxMemFile::GetC()
{
	if (m_pBuffer==NULL || m_Position >= (int32_t)m_Size){
		m_bEOF = true;
		return EOF;
	}
	return *(uint8_t*)((uint8_t*)m_pBuffer + m_Position++);
}
//////////////////////////////////////////////////////////
char * CxMemFile::GetS(char *string, int32_t n)
{
	n--;
	int32_t c,i=0;
	while (i<n){
		c = GetC();
		if (c == EOF) return 0;
		string[i++] = (char)c;
		if (c == '\n') break;
	}
	string[i] = 0;
	return string;
}
//////////////////////////////////////////////////////////
int32_t	CxMemFile::Scanf(const char *format, void* output)
{
	return 0;
}
//////////////////////////////////////////////////////////
bool CxMemFile::Alloc(uint32_t dwNewLen)
{
	if (dwNewLen > (uint32_t)m_Edge)
	{
		// find new buffer size
		uint32_t dwNewBufferSize = (uint32_t)(((dwNewLen>>16)+1)<<16);

		// allocate new buffer
		if (m_pBuffer == NULL) m_pBuffer = (uint8_t*)malloc(dwNewBufferSize);
		else	m_pBuffer = (uint8_t*)realloc(m_pBuffer, dwNewBufferSize);
		// I own this buffer now (caller knows nothing about it)
		m_bFreeOnClose = true;

		m_Edge = dwNewBufferSize;
	}
	return (m_pBuffer!=0);
}
//////////////////////////////////////////////////////////
void CxMemFile::Free()
{
	Close();
}
//////////////////////////////////////////////////////////