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/condrender.h"
  34 #include "main/image.h"
  35 #include "main/macros.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( struct gl_context *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    if (!_mesa_check_conditional_render(ctx))
  60       return; /* don't draw */
  61
  62    bitmap = (const GLubyte *) _mesa_map_pbo_source(ctx, unpack, bitmap);
  63    if (!bitmap)
  64       return;
  65
  66    swrast_render_start(ctx);
  67
  68    if (SWRAST_CONTEXT(ctx)->NewState)
  69       _swrast_validate_derived( ctx );
  70
  71    INIT_SPAN(span, GL_BITMAP);
  72    span.end = width;
  73    span.arrayMask = SPAN_XY;
  74    _swrast_span_default_attribs(ctx, &span);
  75
  76    for (row = 0; row < height; row++) {
  77       const GLubyte *src = (const GLubyte *) _mesa_image_address2d(unpack,
  78                  bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, row, 0);
  79
  80       if (unpack->LsbFirst) {
  81          /* Lsb first */
  82          GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
  83          for (col = 0; col < width; col++) {
  84             if (*src & mask) {
  85                span.array->x[count] = px + col;
  86                span.array->y[count] = py + row;
  87                count++;
  88             }
  89             if (mask == 128U) {
  90                src++;
  91                mask = 1U;
  92             }
  93             else {
  94                mask = mask << 1;
  95             }
  96          }
  97
  98          /* get ready for next row */
  99          if (mask != 1)
 100             src++;
 101       }
 102       else {
 103          /* Msb first */
 104          GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
 105          for (col = 0; col < width; col++) {
 106             if (*src & mask) {
 107                span.array->x[count] = px + col;
 108                span.array->y[count] = py + row;
 109                count++;
 110             }
 111             if (mask == 1U) {
 112                src++;
 113                mask = 128U;
 114             }
 115             else {
 116                mask = mask >> 1;
 117             }
 118          }
 119
 120          /* get ready for next row */
 121          if (mask != 128)
 122             src++;
 123       }
 124
 125       if (count + width >= MAX_WIDTH || row + 1 == height) {
 126          /* flush the span */
 127          span.end = count;
 128          _swrast_write_rgba_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( struct gl_context *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          _swrast_write_rgba_span(ctx, &span);
 193
 194          /* get ready for next row */
 195          if (mask != 1)
 196             src++;
 197       }
 198       else {
 199          /* Msb first */
 200          GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
 201          for (col=0; col<width; col++) {
 202             span.array->mask[col] = (*src & mask) ? GL_TRUE : GL_FALSE;
 203             if (mask == 1U) {
 204                src++;
 205                mask = 128U;
 206             }
 207             else {
 208                mask = mask >> 1;
 209             }
 210          }
 211
 212          _swrast_write_rgba_span(ctx, &span);
 213
 214          /* get ready for next row */
 215          if (mask != 128)
 216             src++;
 217       }
 218    }
 219
 220    swrast_render_finish(ctx);
 221 }
 222 #endif