src/mesa/swrast/s_bitmap.c

   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  */
  47 void
  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    GLint row, col;
  54    GLuint count = 0;
  55    SWspan span;
  56
  57    ASSERT(ctx->RenderMode == GL_RENDER);
  58
  59    bitmap = (const GLubyte *) _mesa_map_pbo_source(ctx, unpack, bitmap);
  60    if (!bitmap)
  61       return;
  62
  63    swrast_render_start(ctx);
  64
  65    if (SWRAST_CONTEXT(ctx)->NewState)
  66       _swrast_validate_derived( ctx );
  67
  68    INIT_SPAN(span, GL_BITMAP);
  69    span.end = width;
  70    span.arrayMask = SPAN_XY;
  71    _swrast_span_default_attribs(ctx, &span);
  72
  73    for (row = 0; row < height; row++) {
  74       const GLubyte *src = (const GLubyte *) _mesa_image_address2d(unpack,
  75                  bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, row, 0);
  76
  77       if (unpack->LsbFirst) {
  78          /* Lsb first */
  79          GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
  80          for (col = 0; col < width; col++) {
  81             if (*src & mask) {
  82                span.array->x[count] = px + col;
  83                span.array->y[count] = py + row;
  84                count++;
  85             }
  86             if (mask == 128U) {
  87                src++;
  88                mask = 1U;
  89             }
  90             else {
  91                mask = mask << 1;
  92             }
  93          }
  94
  95          /* get ready for next row */
  96          if (mask != 1)
  97             src++;
  98       }
  99       else {
 100          /* Msb first */
 101          GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
 102          for (col = 0; col < width; col++) {
 103             if (*src & mask) {
 104                span.array->x[count] = px + col;
 105                span.array->y[count] = py + row;
 106                count++;
 107             }
 108             if (mask == 1U) {
 109                src++;
 110                mask = 128U;
 111             }
 112             else {
 113                mask = mask >> 1;
 114             }
 115          }
 116
 117          /* get ready for next row */
 118          if (mask != 128)
 119             src++;
 120       }
 121
 122       if (count + width >= MAX_WIDTH || row + 1 == height) {
 123          /* flush the span */
 124          span.end = count;
 125          if (ctx->Visual.rgbMode)
 126             _swrast_write_rgba_span(ctx, &span);
 127          else
 128             _swrast_write_index_span(ctx, &span);
 129          span.end = 0;
 130          count = 0;
 131       }
 132    }
 133
 134    swrast_render_finish(ctx);
 135
 136    _mesa_unmap_pbo_source(ctx, unpack);
 137 }
 138
 139
 140 #if 0
 141 /*
 142  * XXX this is another way to implement Bitmap.  Use horizontal runs of
 143  * fragments, initializing the mask array to indicate which fragments to
 144  * draw or skip.
 145  */
 146 void
 147 _swrast_Bitmap( GLcontext *ctx, GLint px, GLint py,
 148                 GLsizei width, GLsizei height,
 149                 const struct gl_pixelstore_attrib *unpack,
 150                 const GLubyte *bitmap )
 151 {
 152    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 153    GLint row, col;
 154    SWspan span;
 155
 156    ASSERT(ctx->RenderMode == GL_RENDER);
 157    ASSERT(bitmap);
 158
 159    swrast_render_start(ctx);
 160
 161    if (SWRAST_CONTEXT(ctx)->NewState)
 162       _swrast_validate_derived( ctx );
 163
 164    INIT_SPAN(span, GL_BITMAP);
 165    span.end = width;
 166    span.arrayMask = SPAN_MASK;
 167    _swrast_span_default_attribs(ctx, &span);
 168
 169    /*span.arrayMask |= SPAN_MASK;*/  /* we'll init span.mask[] */
 170    span.x = px;
 171    span.y = py;
 172    /*span.end = width;*/
 173
 174    for (row=0; row<height; row++, span.y++) {
 175       const GLubyte *src = (const GLubyte *) _mesa_image_address2d(unpack,
 176                  bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, row, 0);
 177
 178       if (unpack->LsbFirst) {
 179          /* Lsb first */
 180          GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
 181          for (col=0; col<width; col++) {
 182             span.array->mask[col] = (*src & mask) ? GL_TRUE : GL_FALSE;
 183             if (mask == 128U) {
 184                src++;
 185                mask = 1U;
 186             }
 187             else {
 188                mask = mask << 1;
 189             }
 190          }
 191
 192          if (ctx->Visual.rgbMode)
 193             _swrast_write_rgba_span(ctx, &span);
 194          else
 195             _swrast_write_index_span(ctx, &span);
 196
 197          /* get ready for next row */
 198          if (mask != 1)
 199             src++;
 200       }
 201       else {
 202          /* Msb first */
 203          GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
 204          for (col=0; col<width; col++) {
 205             span.array->mask[col] = (*src & mask) ? GL_TRUE : GL_FALSE;
 206             if (mask == 1U) {
 207                src++;
 208                mask = 128U;
 209             }
 210             else {
 211                mask = mask >> 1;
 212             }
 213          }
 214
 215          if (ctx->Visual.rgbMode)
 216             _swrast_write_rgba_span(ctx, &span);
 217          else
 218             _swrast_write_index_span(ctx, &span);
 219
 220          /* get ready for next row */
 221          if (mask != 128)
 222             src++;
 223       }
 224    }
 225
 226    swrast_render_finish(ctx);
 227 }
 228 #endif