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    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  */
 147 void
 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