1 | /*****************************************************************************/ |
2 | /* */ |
3 | /* bitmap.c */ |
4 | /* */ |
5 | /* Bitmap definition 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 "check.h" |
38 | #include "xmalloc.h" |
39 | |
40 | /* sp65 */ |
41 | #include "bitmap.h" |
42 | #include "error.h" |
43 | |
44 | |
45 | |
46 | /*****************************************************************************/ |
47 | /* Code */ |
48 | /*****************************************************************************/ |
49 | |
50 | |
51 | |
52 | Bitmap* NewBitmap (unsigned Width, unsigned Height) |
53 | /* Create a new bitmap. The type is set to unknown and the palette to NULL */ |
54 | { |
55 | Bitmap* B; |
56 | |
57 | /* Calculate the size of the bitmap in pixels */ |
58 | unsigned long Size = (unsigned long) Width * Height; |
59 | |
60 | /* Some safety checks */ |
61 | PRECONDITION (Size > 0 && Size <= BM_MAX_SIZE); |
62 | |
63 | /* Allocate memory */ |
64 | B = xmalloc (sizeof (*B) + (Size - 1) * sizeof (B->Data[0])); |
65 | |
66 | /* Initialize the data */ |
67 | B->Name = EmptyStrBuf; |
68 | B->Width = Width; |
69 | B->Height = Height; |
70 | B->Pal = 0; |
71 | |
72 | /* Return the bitmap */ |
73 | return B; |
74 | } |
75 | |
76 | |
77 | |
78 | void FreeBitmap (Bitmap* B) |
79 | /* Free a dynamically allocated bitmap */ |
80 | { |
81 | /* Alloc NULL pointers */ |
82 | if (B != 0) { |
83 | /* Free name, palette and then the bitmap */ |
84 | SB_Done (&B->Name); |
85 | xfree (B->Pal); |
86 | xfree(B); |
87 | } |
88 | } |
89 | |
90 | |
91 | |
92 | int ValidBitmapSize (unsigned Width, unsigned Height) |
93 | /* Return true if this is a valid size for a bitmap */ |
94 | { |
95 | /* Calculate the size of the bitmap in pixels */ |
96 | unsigned long Size = (unsigned long) Width * Height; |
97 | |
98 | /* Check the size */ |
99 | return (Size > 0 && Size <= BM_MAX_SIZE); |
100 | } |
101 | |
102 | |
103 | |
104 | Bitmap* SliceBitmap (const Bitmap* O, unsigned OrigX, unsigned OrigY, |
105 | unsigned Width, unsigned Height) |
106 | /* Create a slice of the given bitmap. The slice starts at position X/Y of |
107 | ** the original and has the given width and height. Location 0/0 is at the |
108 | ** upper left corner. |
109 | */ |
110 | { |
111 | Bitmap* B; |
112 | unsigned Y; |
113 | |
114 | |
115 | /* Check the coordinates and size */ |
116 | PRECONDITION (OrigX + Width <= O->Width && OrigY + Height <= O->Height); |
117 | |
118 | /* Create a new bitmap with the given size */ |
119 | B = NewBitmap (Width, Height); |
120 | |
121 | /* Copy fields from the original */ |
122 | if (SB_GetLen (&O->Name) > 0) { |
123 | SB_CopyStr (&B->Name, "Slice of " ); |
124 | SB_Append (&B->Name, &O->Name); |
125 | } |
126 | B->Pal = DupPalette (O->Pal); |
127 | |
128 | /* Copy the pixel data */ |
129 | for (Y = 0; Y < Height; ++Y) { |
130 | memcpy (B->Data + Y * B->Width, |
131 | O->Data + (OrigY + Y) * O->Width + OrigX, |
132 | Width * sizeof (O->Data[0])); |
133 | } |
134 | |
135 | /* Return the slice */ |
136 | return B; |
137 | } |
138 | |
139 | |
140 | |
141 | Color GetPixelColor (const Bitmap* B, unsigned X, unsigned Y) |
142 | /* Get the color for a given pixel. For indexed bitmaps, the palette entry |
143 | ** is returned. |
144 | */ |
145 | { |
146 | /* Get the pixel at the given coordinates */ |
147 | Pixel P = GetPixel (B, X, Y); |
148 | |
149 | /* If the bitmap has a palette, return the color from the palette. For |
150 | ** simplicity, we will only check the palette, not the type. |
151 | */ |
152 | if (B->Pal) { |
153 | if (P.Index >= B->Pal->Count) { |
154 | /* Palette index is invalid */ |
155 | Error ("Invalid palette index %u at position %u/%u of \"%*s\"" , |
156 | P.Index, X, Y, SB_GetLen (&B->Name), |
157 | SB_GetConstBuf (&B->Name)); |
158 | } |
159 | return B->Pal->Entries[P.Index]; |
160 | } else { |
161 | return P.C; |
162 | } |
163 | } |
164 | |
165 | |
166 | |
167 | Pixel GetPixel (const Bitmap* B, unsigned X, unsigned Y) |
168 | /* Return a pixel from the bitmap. The returned value may either be a color |
169 | ** or a palette index, depending on the type of the bitmap. |
170 | */ |
171 | { |
172 | /* Check the coordinates */ |
173 | PRECONDITION (X < B->Width && Y < B->Height); |
174 | |
175 | /* Return the pixel */ |
176 | return B->Data[Y * B->Width + X]; |
177 | } |
178 | |