s_bitmap.c revision c1f859d4 
1/*
2 * Mesa 3-D graphics library
3 * Version:  7.1
4 *
5 * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR 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/image.h"
34#include "main/macros.h"
35#include "main/pixel.h"
36
37#include "s_context.h"
38#include "s_span.h"
39
40
41
42/**
43 * Render a bitmap.
44 * Called via ctx->Driver.Bitmap()
45 * All parameter error checking will have been done before this is called.
46 */
47void
48_swrast_Bitmap( GLcontext *ctx, GLint px, GLint py,
49		GLsizei width, GLsizei height,
50		const struct gl_pixelstore_attrib *unpack,
51		const GLubyte *bitmap )
52{
53   SWcontext *swrast = SWRAST_CONTEXT(ctx);
54   GLint row, col;
55   GLuint count = 0;
56   SWspan span;
57
58   ASSERT(ctx->RenderMode == GL_RENDER);
59
60   bitmap = _mesa_map_bitmap_pbo(ctx, unpack, bitmap);
61   if (!bitmap)
62      return;
63
64   RENDER_START(swrast,ctx);
65
66   if (SWRAST_CONTEXT(ctx)->NewState)
67      _swrast_validate_derived( ctx );
68
69   INIT_SPAN(span, GL_BITMAP);
70   span.end = width;
71   span.arrayMask = SPAN_XY;
72   _swrast_span_default_attribs(ctx, &span);
73
74   for (row = 0; row < height; row++) {
75      const GLubyte *src = (const GLubyte *) _mesa_image_address2d(unpack,
76                 bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, row, 0);
77
78      if (unpack->LsbFirst) {
79         /* Lsb first */
80         GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
81         for (col = 0; col < width; col++) {
82            if (*src & mask) {
83               span.array->x[count] = px + col;
84               span.array->y[count] = py + row;
85               count++;
86            }
87            if (mask == 128U) {
88               src++;
89               mask = 1U;
90            }
91            else {
92               mask = mask << 1;
93            }
94         }
95
96         /* get ready for next row */
97         if (mask != 1)
98            src++;
99      }
100      else {
101         /* Msb first */
102         GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
103         for (col = 0; col < width; col++) {
104            if (*src & mask) {
105               span.array->x[count] = px + col;
106               span.array->y[count] = py + row;
107               count++;
108            }
109            if (mask == 1U) {
110               src++;
111               mask = 128U;
112            }
113            else {
114               mask = mask >> 1;
115            }
116         }
117
118         /* get ready for next row */
119         if (mask != 128)
120            src++;
121      }
122
123      if (count + width >= MAX_WIDTH || row + 1 == height) {
124         /* flush the span */
125         span.end = count;
126         if (ctx->Visual.rgbMode)
127            _swrast_write_rgba_span(ctx, &span);
128         else
129            _swrast_write_index_span(ctx, &span);
130         span.end = 0;
131         count = 0;
132      }
133   }
134
135   RENDER_FINISH(swrast,ctx);
136
137   _mesa_unmap_bitmap_pbo(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 */
147void
148_swrast_Bitmap( GLcontext *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   RENDER_START(swrast,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         if (ctx->Visual.rgbMode)
194            _swrast_write_rgba_span(ctx, &span);
195         else
196	    _swrast_write_index_span(ctx, &span);
197
198         /* get ready for next row */
199         if (mask != 1)
200            src++;
201      }
202      else {
203         /* Msb first */
204         GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
205         for (col=0; col<width; col++) {
206            span.array->mask[col] = (*src & mask) ? GL_TRUE : GL_FALSE;
207            if (mask == 1U) {
208               src++;
209               mask = 128U;
210            }
211            else {
212               mask = mask >> 1;
213            }
214         }
215
216         if (ctx->Visual.rgbMode)
217            _swrast_write_rgba_span(ctx, &span);
218         else
219            _swrast_write_index_span(ctx, &span);
220
221         /* get ready for next row */
222         if (mask != 128)
223            src++;
224      }
225   }
226
227   RENDER_FINISH(swrast,ctx);
228}
229#endif
230