1 | /*****************************************************************************/ |
2 | /* */ |
3 | /* geosbitmap.c */ |
4 | /* */ |
5 | /* GEOS compacted bitmap backend for the sp65 sprite and bitmap utility */ |
6 | /* */ |
7 | /* */ |
8 | /* */ |
9 | /* (C) 2012, Ullrich von Bassewitz */ |
10 | /* Roemerstrasse 52 */ |
11 | /* D-70794 Filderstadt */ |
12 | /* EMail: uz@cc65.org */ |
13 | /* */ |
14 | /* */ |
15 | /* This software is provided 'as-is', without any expressed or implied */ |
16 | /* warranty. In no event will the authors be held liable for any damages */ |
17 | /* arising from the use of this software. */ |
18 | /* */ |
19 | /* Permission is granted to anyone to use this software for any purpose, */ |
20 | /* including commercial applications, and to alter it and redistribute it */ |
21 | /* freely, subject to the following restrictions: */ |
22 | /* */ |
23 | /* 1. The origin of this software must not be misrepresented; you must not */ |
24 | /* claim that you wrote the original software. If you use this software */ |
25 | /* in a product, an acknowledgment in the product documentation would be */ |
26 | /* appreciated but is not required. */ |
27 | /* 2. Altered source versions must be plainly marked as such, and must not */ |
28 | /* be misrepresented as being the original software. */ |
29 | /* 3. This notice may not be removed or altered from any source */ |
30 | /* distribution. */ |
31 | /* */ |
32 | /*****************************************************************************/ |
33 | |
34 | |
35 | |
36 | /* common */ |
37 | #include "attrib.h" |
38 | #include "print.h" |
39 | #include "xmalloc.h" |
40 | |
41 | /* sp65 */ |
42 | #include "attr.h" |
43 | #include "error.h" |
44 | #include "geosbitmap.h" |
45 | |
46 | |
47 | |
48 | /*****************************************************************************/ |
49 | /* Data */ |
50 | /*****************************************************************************/ |
51 | |
52 | |
53 | |
54 | #define UNIQUE_MAX 91U /* Maximum number of unique bytes */ |
55 | #define REPEAT_MAX 127U /* Maximum number of repeated bytes */ |
56 | |
57 | |
58 | |
59 | /* Structure used for RLE compression */ |
60 | struct RLE { |
61 | unsigned char* Buf; /* Pointer to pixel buffer */ |
62 | unsigned Remaining; /* Remaining bytes in buffer */ |
63 | unsigned char LastVal; /* Last value seen */ |
64 | unsigned Count; /* Number of occurrences for LastVal */ |
65 | StrBuf* D; /* Buffer for compressed data */ |
66 | StrBuf UniqueData; /* Temp buffer for unique data */ |
67 | }; |
68 | |
69 | |
70 | |
71 | /*****************************************************************************/ |
72 | /* Code */ |
73 | /*****************************************************************************/ |
74 | |
75 | |
76 | |
77 | static void StoreByte (struct RLE* RLE) |
78 | /* Store a unique byte or a run of repeated bytes. If count is zero, the |
79 | ** function will flush the internal buffers, so that all data is in RLE->D. |
80 | */ |
81 | { |
82 | |
83 | |
84 | if (RLE->Count == 1 || RLE->Count == 2) { |
85 | /* A run of two identical bytes is treated as two unique bytes, since |
86 | ** this will usually merge with the following run. |
87 | */ |
88 | SB_AppendChar (&RLE->UniqueData, RLE->LastVal); |
89 | if (RLE->Count == 2) { |
90 | SB_AppendChar (&RLE->UniqueData, RLE->LastVal); |
91 | } |
92 | |
93 | /* Clear the repeat counter */ |
94 | RLE->Count = 0; |
95 | |
96 | } else { |
97 | |
98 | /* Run of repeated bytes. First flush the temp buffer for unique |
99 | ** bytes. |
100 | */ |
101 | const char* Buf = SB_GetConstBuf (&RLE->UniqueData); |
102 | unsigned Count = SB_GetLen (&RLE->UniqueData); |
103 | while (Count) { |
104 | |
105 | /* Determine the count for this sequence */ |
106 | unsigned Chunk = Count; |
107 | if (Chunk > UNIQUE_MAX) { |
108 | Chunk = UNIQUE_MAX; |
109 | } |
110 | |
111 | /* Output the unique op */ |
112 | SB_AppendChar (RLE->D, 0x80 + (unsigned char) Chunk); |
113 | SB_AppendBuf (RLE->D, Buf, Chunk); |
114 | |
115 | /* Bump the counters */ |
116 | Buf += Chunk; |
117 | Count -= Chunk; |
118 | } |
119 | |
120 | /* Clear the unique byte buffer */ |
121 | SB_Clear (&RLE->UniqueData); |
122 | |
123 | /* Now output the repeat sequence */ |
124 | while (RLE->Count) { |
125 | |
126 | /* Determine the count for this sequence */ |
127 | unsigned Chunk = RLE->Count; |
128 | if (Chunk > REPEAT_MAX) { |
129 | Chunk = REPEAT_MAX; |
130 | } |
131 | /* Output the repeat op */ |
132 | SB_AppendChar (RLE->D, (unsigned char) Chunk); |
133 | SB_AppendChar (RLE->D, RLE->LastVal); |
134 | |
135 | /* Bump the counters */ |
136 | RLE->Count -= Chunk; |
137 | } |
138 | } |
139 | } |
140 | |
141 | |
142 | |
143 | StrBuf* GenGeosBitmap (const Bitmap* B, const Collection* A attribute ((unused))) |
144 | /* Generate binary output in GEOS compacted bitmap format for the bitmap B. |
145 | ** The output is stored in a string buffer (which is actually a dynamic char |
146 | ** array) and returned. |
147 | */ |
148 | { |
149 | unsigned LineWidth; |
150 | unsigned char* Buf; |
151 | unsigned char* BP; |
152 | StrBuf* D; |
153 | unsigned X, Y; |
154 | struct RLE RLE; |
155 | |
156 | |
157 | /* Output the image properties */ |
158 | Print (stdout, 1, "Image is %ux%u with %u colors%s\n" , |
159 | GetBitmapWidth (B), GetBitmapHeight (B), GetBitmapColors (B), |
160 | BitmapIsIndexed (B)? " (indexed)" : "" ); |
161 | |
162 | /* Check the bitmap properties */ |
163 | if (!BitmapIsIndexed (B) || GetBitmapColors (B) > 2) { |
164 | Error ("Bitmaps converted to GEOS compacted bitmap must be " |
165 | "indexed with two colors" ); |
166 | } |
167 | |
168 | /* Calculate the width of one line in bytes */ |
169 | LineWidth = (GetBitmapWidth (B) + 7U) / 8U; |
170 | |
171 | /* Allocate a buffer for the raw image */ |
172 | Buf = xmalloc (LineWidth * GetBitmapHeight (B)); |
173 | |
174 | /* Convert the bitmap into a raw image */ |
175 | BP = Buf; |
176 | for (Y = 0; Y < GetBitmapHeight (B); ++Y) { |
177 | for (X = 0; X < GetBitmapWidth (B); ) { |
178 | unsigned char V = 0; |
179 | int Bits = 8; |
180 | if ((unsigned)Bits > GetBitmapWidth (B) - X) { |
181 | Bits = (GetBitmapWidth (B) - X); |
182 | } |
183 | while (--Bits >= 0) { |
184 | V |= (GetPixel (B, X++, Y).Index & 0x01) << Bits; |
185 | } |
186 | *BP++ = V; |
187 | } |
188 | } |
189 | |
190 | /* Create the output buffer and resize it to something reasonable */ |
191 | D = NewStrBuf (); |
192 | SB_Realloc (D, 64); |
193 | |
194 | /* Compact the image. We're currently using only REPEAT and UNIQUE opcodes. |
195 | ** BIGCOUNT is rather difficult to apply. |
196 | */ |
197 | RLE.Buf = Buf; |
198 | RLE.Remaining = LineWidth * GetBitmapHeight (B) - 1; |
199 | RLE.LastVal = *RLE.Buf++; |
200 | RLE.Count = 1; |
201 | RLE.D = D; |
202 | RLE.UniqueData = EmptyStrBuf; |
203 | while (RLE.Remaining--) { |
204 | /* */ |
205 | if (RLE.LastVal == *RLE.Buf) { |
206 | ++RLE.Buf; |
207 | ++RLE.Count; |
208 | } else { |
209 | StoreByte (&RLE); |
210 | RLE.LastVal = *RLE.Buf++; |
211 | RLE.Count = 1; |
212 | } |
213 | } |
214 | |
215 | /* If something remains, store it */ |
216 | if (RLE.Count) { |
217 | StoreByte (&RLE); |
218 | } |
219 | |
220 | /* Flush the unique byte buffer */ |
221 | StoreByte (&RLE); |
222 | |
223 | /* Release the unique byte buffer */ |
224 | SB_Done (&RLE.UniqueData); |
225 | |
226 | /* Free the raw image buffer */ |
227 | xfree (Buf); |
228 | |
229 | /* Return the converted bitmap */ |
230 | return D; |
231 | } |
232 | |