s_bitmap.c   [plain text]

/*
 * Mesa 3-D graphics library
 * Version:  5.0
 *
 * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * \file swrast/s_bitmap.c
 * \brief glBitmap rendering.
 * \author Brian Paul
 */

#include "glheader.h"
#include "image.h"
#include "macros.h"
#include "mmath.h"
#include "pixel.h"

#include "s_context.h"
#include "s_span.h"



/*
 * Render a bitmap.
 */
void
_swrast_Bitmap( GLcontext *ctx, GLint px, GLint py,
		GLsizei width, GLsizei height,
		const struct gl_pixelstore_attrib *unpack,
		const GLubyte *bitmap )
{
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   GLint row, col;
   GLuint count = 0;
   struct sw_span span;

   ASSERT(ctx->RenderMode == GL_RENDER);
   ASSERT(bitmap);

   RENDER_START(swrast,ctx);

   if (SWRAST_CONTEXT(ctx)->NewState)
      _swrast_validate_derived( ctx );

   INIT_SPAN(span, GL_BITMAP, width, 0, SPAN_XY);

   if (ctx->Visual.rgbMode) {
      span.interpMask |= SPAN_RGBA;
      span.red   = FloatToFixed(ctx->Current.RasterColor[0] * CHAN_MAXF);
      span.green = FloatToFixed(ctx->Current.RasterColor[1] * CHAN_MAXF);
      span.blue  = FloatToFixed(ctx->Current.RasterColor[2] * CHAN_MAXF);
      span.alpha = FloatToFixed(ctx->Current.RasterColor[3] * CHAN_MAXF);
      span.redStep = span.greenStep = span.blueStep = span.alphaStep = 0;
   }
   else {
      span.interpMask |= SPAN_INDEX;
      span.index = ChanToFixed(ctx->Current.RasterIndex);
      span.indexStep = 0;
   }

   if (ctx->Depth.Test)
      _mesa_span_default_z(ctx, &span);
   if (ctx->Fog.Enabled)
      _mesa_span_default_fog(ctx, &span);
   if (ctx->Texture._EnabledUnits)
      _mesa_span_default_texcoords(ctx, &span);

   for (row = 0; row < height; row++, span.y++) {
      const GLubyte *src = (const GLubyte *) _mesa_image_address( unpack,
                 bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, 0, row, 0 );

      if (unpack->LsbFirst) {
         /* Lsb first */
         GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
         for (col = 0; col < width; col++) {
            if (*src & mask) {
               span.array->x[count] = px + col;
               span.array->y[count] = py + row;
               count++;
            }
            if (mask == 128U) {
               src++;
               mask = 1U;
            }
            else {
               mask = mask << 1;
            }
         }

         /* get ready for next row */
         if (mask != 1)
            src++;
      }
      else {
         /* Msb first */
         GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
         for (col = 0; col < width; col++) {
            if (*src & mask) {
               span.array->x[count] = px + col;
               span.array->y[count] = py + row;
               count++;
            }
            if (mask == 1U) {
               src++;
               mask = 128U;
            }
            else {
               mask = mask >> 1;
            }
         }

         /* get ready for next row */
         if (mask != 128)
            src++;
      }

      if (count + width >= MAX_WIDTH || row + 1 == height) {
         /* flush the span */
         span.end = count;
         if (ctx->Visual.rgbMode)
            _mesa_write_rgba_span(ctx, &span);
         else
            _mesa_write_index_span(ctx, &span);
         span.end = 0;
         count = 0;
      }
   }

   RENDER_FINISH(swrast,ctx);
}


#if 0
/*
 * XXX this is another way to implement Bitmap.  Use horizontal runs of
 * fragments, initializing the mask array to indicate which fragmens to
 * draw or skip.
 */
void
_swrast_Bitmap( GLcontext *ctx, GLint px, GLint py,
		GLsizei width, GLsizei height,
		const struct gl_pixelstore_attrib *unpack,
		const GLubyte *bitmap )
{
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   GLint row, col;
   struct sw_span span;

   ASSERT(ctx->RenderMode == GL_RENDER);
   ASSERT(bitmap);

   RENDER_START(swrast,ctx);

   if (SWRAST_CONTEXT(ctx)->NewState)
      _swrast_validate_derived( ctx );

   INIT_SPAN(span, GL_BITMAP, width, 0, SPAN_MASK);

   /*span.arrayMask |= SPAN_MASK;*/  /* we'll init span.mask[] */
   span.x = px;
   span.y = py;
   /*span.end = width;*/
   if (ctx->Visual.rgbMode) {
      span.interpMask |= SPAN_RGBA;
      span.red   = FloatToFixed(ctx->Current.RasterColor[0] * CHAN_MAXF);
      span.green = FloatToFixed(ctx->Current.RasterColor[1] * CHAN_MAXF);
      span.blue  = FloatToFixed(ctx->Current.RasterColor[2] * CHAN_MAXF);
      span.alpha = FloatToFixed(ctx->Current.RasterColor[3] * CHAN_MAXF);
      span.redStep = span.greenStep = span.blueStep = span.alphaStep = 0;
   }
   else {
      span.interpMask |= SPAN_INDEX;
      span.index = ChanToFixed(ctx->Current.RasterIndex);
      span.indexStep = 0;
   }

   if (ctx->Depth.Test)
      _mesa_span_default_z(ctx, &span);
   if (ctx->Fog.Enabled)
      _mesa_span_default_fog(ctx, &span);
   if (ctx->Texture._EnabledUnits)
      _mesa_span_default_texcoords(ctx, &span);

   for (row=0; row<height; row++, span.y++) {
      const GLubyte *src = (const GLubyte *) _mesa_image_address( unpack,
                 bitmap, width, height, GL_COLOR_INDEX, GL_BITMAP, 0, row, 0 );

      if (unpack->LsbFirst) {
         /* Lsb first */
         GLubyte mask = 1U << (unpack->SkipPixels & 0x7);
         for (col=0; col<width; col++) {
            span.array->mask[col] = (*src & mask) ? GL_TRUE : GL_FALSE;
            if (mask == 128U) {
               src++;
               mask = 1U;
            }
            else {
               mask = mask << 1;
            }
         }

         if (ctx->Visual.rgbMode)
            _mesa_write_rgba_span(ctx, &span);
         else
	    _mesa_write_index_span(ctx, &span);

         /* get ready for next row */
         if (mask != 1)
            src++;
      }
      else {
         /* Msb first */
         GLubyte mask = 128U >> (unpack->SkipPixels & 0x7);
         for (col=0; col<width; col++) {
            span.array->mask[col] = (*src & mask) ? GL_TRUE : GL_FALSE;
            if (mask == 1U) {
               src++;
               mask = 128U;
            }
            else {
               mask = mask >> 1;
            }
         }

         if (ctx->Visual.rgbMode)
            _mesa_write_rgba_span(ctx, &span);
         else
            _mesa_write_index_span(ctx, &span);

         /* get ready for next row */
         if (mask != 128)
            src++;
      }
   }

   RENDER_FINISH(swrast,ctx);
}
#endif