1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25 /**
26 * \file swrast/s_bitmap.c
27 * \brief glBitmap rendering.
28 * \author Brian Paul
29 */
30
31 #include "main/glheader.h"
32 #include "main/bufferobj.h"
33 #include "main/condrender.h"
34 #include "main/image.h"
35 #include "main/macros.h"
36 #include "main/pbo.h"
37
38 #include "s_context.h"
39 #include "s_span.h"
40
41
42
43 /**
44 * Render a bitmap.
45 * Called via ctx->Driver.Bitmap()
46 * All parameter error checking will have been done before this is called.
47 */
48 void
_swrast_Bitmap(struct gl_context * ctx,GLint px,GLint py,GLsizei width,GLsizei height,const struct gl_pixelstore_attrib * unpack,const GLubyte * bitmap)49 _swrast_Bitmap( struct gl_context *ctx, GLint px, GLint py,
50 GLsizei width, GLsizei height,
51 const struct gl_pixelstore_attrib *unpack,
52 const GLubyte *bitmap )
53 {
54 GLint row, col;
55 GLuint count = 0;
56 SWspan span;
57
58 assert(ctx->RenderMode == GL_RENDER);
59
60 if (!_mesa_check_conditional_render(ctx))
61 return; /* don't draw */
62
63 bitmap = (const GLubyte *) _mesa_map_pbo_source(ctx, unpack, bitmap);
64 if (!bitmap)
65 return;
66
67 swrast_render_start(ctx);
68
69 if (SWRAST_CONTEXT(ctx)->NewState)
70 _swrast_validate_derived( ctx );
71
72 INIT_SPAN(span, GL_BITMAP);
73 span.end = width;
74 span.arrayMask = SPAN_XY;
75 _swrast_span_default_attribs(ctx, &span);
76
77 for (row = 0; row < height; row++) {
78 const GLubyte *src = (const GLubyte *) _mesa_image_address2d(unpack,
79 bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, row, 0);
80
81 if (unpack->LsbFirst) {
82 /* Lsb first */
83 GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
84 for (col = 0; col < width; col++) {
85 if (*src & mask) {
86 span.array->x[count] = px + col;
87 span.array->y[count] = py + row;
88 count++;
89 }
90 if (mask == 128U) {
91 src++;
92 mask = 1U;
93 }
94 else {
95 mask = mask << 1;
96 }
97 }
98
99 /* get ready for next row */
100 if (mask != 1)
101 src++;
102 }
103 else {
104 /* Msb first */
105 GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
106 for (col = 0; col < width; col++) {
107 if (*src & mask) {
108 span.array->x[count] = px + col;
109 span.array->y[count] = py + row;
110 count++;
111 }
112 if (mask == 1U) {
113 src++;
114 mask = 128U;
115 }
116 else {
117 mask = mask >> 1;
118 }
119 }
120
121 /* get ready for next row */
122 if (mask != 128)
123 src++;
124 }
125
126 if (count + width >= SWRAST_MAX_WIDTH || row + 1 == height) {
127 /* flush the span */
128 span.end = count;
129 _swrast_write_rgba_span(ctx, &span);
130 span.end = 0;
131 count = 0;
132 }
133 }
134
135 swrast_render_finish(ctx);
136
137 _mesa_unmap_pbo_source(ctx, unpack);
138 }
139
140
141 #if 0
142 /*
143 * XXX this is another way to implement Bitmap. Use horizontal runs of
144 * fragments, initializing the mask array to indicate which fragments to
145 * draw or skip.
146 */
147 void
148 _swrast_Bitmap( struct gl_context *ctx, GLint px, GLint py,
149 GLsizei width, GLsizei height,
150 const struct gl_pixelstore_attrib *unpack,
151 const GLubyte *bitmap )
152 {
153 SWcontext *swrast = SWRAST_CONTEXT(ctx);
154 GLint row, col;
155 SWspan span;
156
157 assert(ctx->RenderMode == GL_RENDER);
158 assert(bitmap);
159
160 swrast_render_start(ctx);
161
162 if (SWRAST_CONTEXT(ctx)->NewState)
163 _swrast_validate_derived( ctx );
164
165 INIT_SPAN(span, GL_BITMAP);
166 span.end = width;
167 span.arrayMask = SPAN_MASK;
168 _swrast_span_default_attribs(ctx, &span);
169
170 /*span.arrayMask |= SPAN_MASK;*/ /* we'll init span.mask[] */
171 span.x = px;
172 span.y = py;
173 /*span.end = width;*/
174
175 for (row=0; row<height; row++, span.y++) {
176 const GLubyte *src = (const GLubyte *) _mesa_image_address2d(unpack,
177 bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, row, 0);
178
179 if (unpack->LsbFirst) {
180 /* Lsb first */
181 GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
182 for (col=0; col<width; col++) {
183 span.array->mask[col] = (*src & mask) ? GL_TRUE : GL_FALSE;
184 if (mask == 128U) {
185 src++;
186 mask = 1U;
187 }
188 else {
189 mask = mask << 1;
190 }
191 }
192
193 _swrast_write_rgba_span(ctx, &span);
194
195 /* get ready for next row */
196 if (mask != 1)
197 src++;
198 }
199 else {
200 /* Msb first */
201 GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
202 for (col=0; col<width; col++) {
203 span.array->mask[col] = (*src & mask) ? GL_TRUE : GL_FALSE;
204 if (mask == 1U) {
205 src++;
206 mask = 128U;
207 }
208 else {
209 mask = mask >> 1;
210 }
211 }
212
213 _swrast_write_rgba_span(ctx, &span);
214
215 /* get ready for next row */
216 if (mask != 128)
217 src++;
218 }
219 }
220
221 swrast_render_finish(ctx);
222 }
223 #endif
224