src/mesa/state_tracker/st_cb_readpixels.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 /**
  30  * glReadPixels interface to pipe
  31  *
  32  * \author Brian Paul
  33  */
  34
  35
  36 #include "main/imports.h"
  37 #include "main/context.h"
  38 #include "main/image.h"
  39
  40 #include "pipe/p_context.h"
  41 #include "pipe/p_defines.h"
  42 #include "st_context.h"
  43 #include "st_cb_readpixels.h"
  44 #include "st_cb_fbo.h"
  45 #include "st_format.h"
  46 #include "st_public.h"
  47
  48
  49 /**
  50  * Do glReadPixels by getting rows from the framebuffer surface with
  51  * get_tile().  Convert to requested format/type with Mesa image routines.
  52  * Image transfer ops are done in software too.
  53  */
  54 static void
  55 st_readpixels(GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height,
  56               GLenum format, GLenum type,
  57               const struct gl_pixelstore_attrib *pack,
  58               GLvoid *dest)
  59 {
  60    struct pipe_context *pipe = ctx->st->pipe;
  61    GLfloat temp[MAX_WIDTH][4];
  62    const GLbitfield transferOps = ctx->_ImageTransferState;
  63    GLint i, yStep, dfStride;
  64    GLfloat *df;
  65    struct st_renderbuffer *strb;
  66    struct gl_pixelstore_attrib clippedPacking = *pack;
  67
  68    /* XXX convolution not done yet */
  69    assert((transferOps & IMAGE_CONVOLUTION_BIT) == 0);
  70
  71    /* Do all needed clipping here, so that we can forget about it later */
  72    if (!_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) {
  73       /* The ReadPixels region is totally outside the window bounds */
  74       return;
  75    }
  76
  77    /* make sure rendering has completed */
  78    pipe->flush(pipe, 0x0);
  79
  80    if (pack->BufferObj && pack->BufferObj->Name) {
  81       /* reading into a PBO */
  82
  83    }
  84    else {
  85       /* reading into user memory/buffer */
  86
  87    }
  88
  89    strb = st_renderbuffer(ctx->ReadBuffer->_ColorReadBuffer);
  90    if (!strb)
  91       return;
  92
  93    pipe->region_map(pipe, strb->surface->region);
  94
  95    if (format == GL_RGBA && type == GL_FLOAT) {
  96       /* write tile(row) directly into user's buffer */
  97       df = (GLfloat *) _mesa_image_address2d(&clippedPacking, dest, width,
  98                                              height, format, type, 0, 0);
  99       dfStride = width * 4;
 100    }
 101    else {
 102       /* write tile(row) into temp row buffer */
 103       df = (GLfloat *) temp;
 104       dfStride = 0;
 105    }
 106
 107    /* determine bottom-to-top vs. top-to-bottom order */
 108    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 109       y = strb->Base.Height - 1 - y;
 110       yStep = -1;
 111    }
 112    else {
 113       yStep = 1;
 114    }
 115
 116    /* Do a row at a time to flip image data vertically */
 117    for (i = 0; i < height; i++) {
 118       strb->surface->get_tile(strb->surface, x, y, width, 1, df);
 119       y += yStep;
 120       df += dfStride;
 121       if (!dfStride) {
 122          /* convert GLfloat to user's format/type */
 123          GLvoid *dst = _mesa_image_address2d(&clippedPacking, dest, width,
 124                                              height, format, type, i, 0);
 125          _mesa_pack_rgba_span_float(ctx, width, temp, format, type, dst,
 126                                     &clippedPacking, transferOps);
 127       }
 128    }
 129
 130    pipe->region_unmap(pipe, strb->surface->region);
 131 }
 132
 133
 134 void st_init_readpixels_functions(struct dd_function_table *functions)
 135 {
 136    functions->ReadPixels = st_readpixels;
 137 }