s_drawpix.c

mesa-6.5-minigui源码

/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2006  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.
 */


#include "glheader.h"
#include "bufferobj.h"
#include "context.h"
#include "convolve.h"
#include "image.h"
#include "macros.h"
#include "imports.h"
#include "pixel.h"
#include "state.h"

#include "s_context.h"
#include "s_drawpix.h"
#include "s_span.h"
#include "s_stencil.h"
#include "s_zoom.h"


/*
 * Try to do a fast and simple RGB(a) glDrawPixels.
 * Return:  GL_TRUE if success, GL_FALSE if slow path must be used instead
 */
static GLboolean
fast_draw_pixels(GLcontext *ctx, GLint x, GLint y,
                 GLsizei width, GLsizei height,
                 GLenum format, GLenum type,
                 const struct gl_pixelstore_attrib *unpack,
                 const GLvoid *pixels)
{
   const GLint imgX = x, imgY = y;
   struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0][0];
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   struct sw_span span;

   INIT_SPAN(span, GL_BITMAP, 0, 0, SPAN_RGBA);

   if (swrast->_RasterMask & MULTI_DRAW_BIT)
      return GL_FALSE;

   if (ctx->Depth.Test)
      _swrast_span_default_z(ctx, &span);
   if (swrast->_FogEnabled)
      _swrast_span_default_fog(ctx, &span);
   if (ctx->Texture._EnabledCoordUnits)
      _swrast_span_default_texcoords(ctx, &span);

   if ((swrast->_RasterMask & ~CLIP_BIT) == 0
       && ctx->Texture._EnabledCoordUnits == 0
       && unpack->Alignment == 1 /* XXX may not really need this */
       && !unpack->SwapBytes
       && !unpack->LsbFirst) {

      /* XXX there's a lot of clipping code here that should be replaced
       * by a call to _mesa_clip_drawpixels().
       */
      GLint destX = x;
      GLint destY = y;
      GLint drawWidth = width;           /* actual width drawn */
      GLint drawHeight = height;         /* actual height drawn */
      GLint skipPixels = unpack->SkipPixels;
      GLint skipRows = unpack->SkipRows;
      GLint rowLength;

      if (unpack->RowLength > 0)
         rowLength = unpack->RowLength;
      else
         rowLength = width;

      /* If we're not using pixel zoom then do all clipping calculations
       * now.  Otherwise, we'll let the _swrast_write_zoomed_*_span() functions
       * handle the clipping.
       */
      if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
         /* horizontal clipping */
         if (destX < ctx->DrawBuffer->_Xmin) {
            skipPixels += (ctx->DrawBuffer->_Xmin - destX);
            drawWidth  -= (ctx->DrawBuffer->_Xmin - destX);
            destX = ctx->DrawBuffer->_Xmin;
         }
         if (destX + drawWidth > ctx->DrawBuffer->_Xmax)
            drawWidth -= (destX + drawWidth - ctx->DrawBuffer->_Xmax);
         if (drawWidth <= 0)
            return GL_TRUE;

         /* vertical clipping */
         if (destY < ctx->DrawBuffer->_Ymin) {
            skipRows   += (ctx->DrawBuffer->_Ymin - destY);
            drawHeight -= (ctx->DrawBuffer->_Ymin - destY);
            destY = ctx->DrawBuffer->_Ymin;
         }
         if (destY + drawHeight > ctx->DrawBuffer->_Ymax)
            drawHeight -= (destY + drawHeight - ctx->DrawBuffer->_Ymax);
         if (drawHeight <= 0)
            return GL_TRUE;
      }
      else if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==-1.0F) {
         /* upside-down image */
         /* horizontal clipping */
         if (destX < ctx->DrawBuffer->_Xmin) {
            skipPixels += (ctx->DrawBuffer->_Xmin - destX);
            drawWidth  -= (ctx->DrawBuffer->_Xmin - destX);
            destX = ctx->DrawBuffer->_Xmin;
         }
         if (destX + drawWidth > ctx->DrawBuffer->_Xmax)
            drawWidth -= (destX + drawWidth - ctx->DrawBuffer->_Xmax);
         if (drawWidth <= 0)
            return GL_TRUE;

         /* vertical clipping */
         if (destY > ctx->DrawBuffer->_Ymax) {
            skipRows   += (destY - ctx->DrawBuffer->_Ymax);
            drawHeight -= (destY - ctx->DrawBuffer->_Ymax);
            destY = ctx->DrawBuffer->_Ymax;
         }
         if (destY - drawHeight < ctx->DrawBuffer->_Ymin)
            drawHeight -= (ctx->DrawBuffer->_Ymin - (destY - drawHeight));
         if (drawHeight <= 0)
            return GL_TRUE;
      }
      else {
         if (drawWidth > MAX_WIDTH)
            return GL_FALSE; /* fall back to general case path */
      }


      /*
       * Ready to draw!
       * The window region at (destX, destY) of size (drawWidth, drawHeight)
       * will be written to.
       * We'll take pixel data from buffer pointed to by "pixels" but we'll
       * skip "skipRows" rows and skip "skipPixels" pixels/row.
       */

      if (format == GL_RGBA && type == CHAN_TYPE
          && ctx->_ImageTransferState==0) {
         if (ctx->Visual.rgbMode) {
            GLchan *src = (GLchan *) pixels
               + (skipRows * rowLength + skipPixels) * 4;
            if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
               /* no zooming */
               GLint row;
               for (row=0; row<drawHeight; row++) {
                  rb->PutRow(ctx, rb, drawWidth, destX, destY, src, NULL);
                  src += rowLength * 4;
                  destY++;
               }
            }
            else if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==-1.0F) {
               /* upside-down */
               GLint row;
               for (row=0; row<drawHeight; row++) {
                  destY--;
                  rb->PutRow(ctx, rb, drawWidth, destX, destY, src, NULL);
                  src += rowLength * 4;
               }
            }
            else {
               /* with zooming */
               GLint row;
               for (row=0; row<drawHeight; row++) {
                  span.x = destX;
                  span.y = destY + row;
                  span.end = drawWidth;
                  _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span,
                                                 (CONST GLchan (*)[4]) src);
                  src += rowLength * 4;
               }
            }
         }
         return GL_TRUE;
      }
      else if (format == GL_RGB && type == CHAN_TYPE
               && ctx->_ImageTransferState == 0) {
         if (ctx->Visual.rgbMode) {
            GLchan *src = (GLchan *) pixels
               + (skipRows * rowLength + skipPixels) * 3;
            if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
               GLint row;
               for (row=0; row<drawHeight; row++) {
                  rb->PutRowRGB(ctx, rb, drawWidth, destX, destY, src, NULL);
                  src += rowLength * 3;
                  destY++;
               }
            }
            else if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==-1.0F) {
               /* upside-down */
               GLint row;
               for (row=0; row<drawHeight; row++) {
                  destY--;
                  rb->PutRowRGB(ctx, rb, drawWidth, destX, destY, src, NULL);
                  src += rowLength * 3;
               }
            }
            else {
               /* with zooming */
               GLint row;
               for (row=0; row<drawHeight; row++) {
                  span.x = destX;
                  span.y = destY;
                  span.end = drawWidth;
                  _swrast_write_zoomed_rgb_span(ctx, imgX, imgY, &span, 
                                         (CONST GLchan (*)[3]) src);
                  src += rowLength * 3;
                  destY++;
               }
            }
         }
         return GL_TRUE;
      }
      else if (format == GL_LUMINANCE && type == CHAN_TYPE
               && ctx->_ImageTransferState==0) {
         if (ctx->Visual.rgbMode) {
            GLchan *src = (GLchan *) pixels
               + (skipRows * rowLength + skipPixels);
            if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
               /* no zooming */
               GLint row;
               ASSERT(drawWidth <= MAX_WIDTH);
               for (row=0; row<drawHeight; row++) {
                  GLint i;
		  for (i=0;i<drawWidth;i++) {
                     span.array->rgb[i][0] = src[i];
                     span.array->rgb[i][1] = src[i];
                     span.array->rgb[i][2] = src[i];
		  }
                  rb->PutRowRGB(ctx, rb, drawWidth, destX, destY,
                                span.array->rgb, NULL);
                  src += rowLength;
                  destY++;
               }
            }
            else if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==-1.0F) {
               /* upside-down */
               GLint row;
               ASSERT(drawWidth <= MAX_WIDTH);
               for (row=0; row<drawHeight; row++) {
                  GLint i;
                  for (i=0;i<drawWidth;i++) {
                     span.array->rgb[i][0] = src[i];
                     span.array->rgb[i][1] = src[i];
                     span.array->rgb[i][2] = src[i];
                  }
                  destY--;
                  rb->PutRow(ctx, rb, drawWidth, destX, destY,
                             span.array->rgb, NULL);
                  src += rowLength;
               }
            }
            else {
               /* with zooming */
               GLint row;
               ASSERT(drawWidth <= MAX_WIDTH);
               for (row=0; row<drawHeight; row++) {
                  GLint i;
		  for (i=0;i<drawWidth;i++) {
                     span.array->rgb[i][0] = src[i];
                     span.array->rgb[i][1] = src[i];
                     span.array->rgb[i][2] = src[i];
		  }
                  span.x = destX;
                  span.y = destY;
                  span.end = drawWidth;
                  _swrast_write_zoomed_rgb_span(ctx, imgX, imgY, &span,
                             (CONST GLchan (*)[3]) span.array->rgb);
                  src += rowLength;
                  destY++;
               }
            }
         }
         return GL_TRUE;
      }
      else if (format == GL_LUMINANCE_ALPHA && type == CHAN_TYPE
               && ctx->_ImageTransferState == 0) {
         if (ctx->Visual.rgbMode) {
            GLchan *src = (GLchan *) pixels
               + (skipRows * rowLength + skipPixels)*2;
            if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==1.0F) {
               /* no zooming */
               GLint row;
               ASSERT(drawWidth <= MAX_WIDTH);
               for (row=0; row<drawHeight; row++) {
                  GLint i;
                  GLchan *ptr = src;
		  for (i=0;i<drawWidth;i++) {
                     span.array->rgba[i][0] = *ptr;
                     span.array->rgba[i][1] = *ptr;
                     span.array->rgba[i][2] = *ptr++;
                     span.array->rgba[i][3] = *ptr++;
		  }
                  rb->PutRow(ctx, rb, drawWidth, destX, destY,
                             span.array->rgba, NULL);
                  src += rowLength*2;
                  destY++;
               }
            }
            else if (ctx->Pixel.ZoomX==1.0F && ctx->Pixel.ZoomY==-1.0F) {
               /* upside-down */
               GLint row;
               ASSERT(drawWidth <= MAX_WIDTH);
               for (row=0; row<drawHeight; row++) {
                  GLint i;
                  GLchan *ptr = src;
                  for (i=0;i<drawWidth;i++) {
                     span.array->rgba[i][0] = *ptr;
                     span.array->rgba[i][1] = *ptr;
                     span.array->rgba[i][2] = *ptr++;
                     span.array->rgba[i][3] = *ptr++;
                  }
                  destY--;
                  rb->PutRow(ctx, rb, drawWidth, destX, destY,
                             span.array->rgba, NULL);
                  src += rowLength*2;
               }
            }
            else {
               /* with zooming */
               GLint row;
               ASSERT(drawWidth <= MAX_WIDTH);
               for (row=0; row<drawHeight; row++) {
                  GLchan *ptr = src;
                  GLint i;
		  for (i=0;i<drawWidth;i++) {
                     span.array->rgba[i][0] = *ptr;
                     span.array->rgba[i][1] = *ptr;
                     span.array->rgba[i][2] = *ptr++;
                     span.array->rgba[i][3] = *ptr++;
		  }
                  span.x = destX;
                  span.y = destY;
                  span.end = drawWidth;
                  _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span,
                            (CONST GLchan (*)[4]) span.array->rgba);
                  src += rowLength*2;
                  destY++;
               }
            }
         }
         return GL_TRUE;
      }
      else if (format==GL_COLOR_INDEX && type==GL_UNSIGNED_BYTE) {
         GLubyte *src = (GLubyte *) pixels + skipRows * rowLength + skipPixels;
         if (ctx->Visual.rgbMode) {