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  * Special case for reading stencil buffer.
  51  * For color/depth we use get_tile().  For stencil, map the stencil buffer.
  52  */
  53 void
  54 st_read_stencil_pixels(GLcontext *ctx, GLint x, GLint y,
  55                        GLsizei width, GLsizei height, GLenum type,
  56                        const struct gl_pixelstore_attrib *packing,
  57                        GLvoid *pixels)
  58 {
  59    struct st_context *st = ctx->st;
  60    struct pipe_context *pipe = st->pipe;
  61    struct gl_framebuffer *fb = ctx->ReadBuffer;
  62    struct st_renderbuffer *strb = st_renderbuffer(fb->_StencilBuffer);
  63    struct pipe_surface *ps = strb->surface;
  64    ubyte *stmap;
  65    GLint j;
  66
  67    /* map the stencil buffer */
  68    stmap = pipe->region_map(pipe, ps->region);
  69
  70    /* width should never be > MAX_WIDTH since we did clipping earlier */
  71    ASSERT(width <= MAX_WIDTH);
  72
  73    /* process image row by row */
  74    for (j = 0; j < height; j++, y++) {
  75       GLvoid *dest;
  76       GLstencil values[MAX_WIDTH];
  77       GLint srcY;
  78
  79       if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
  80          srcY = ctx->DrawBuffer->Height - y - 1;
  81       }
  82       else {
  83          srcY = y;
  84       }
  85
  86       /* get stencil values */
  87       switch (ps->format) {
  88       case PIPE_FORMAT_U_S8:
  89          {
  90             const ubyte *src = stmap + srcY * ps->region->pitch + x;
  91             memcpy(values, src, width);
  92          }
  93          break;
  94       case PIPE_FORMAT_S8_Z24:
  95          {
  96             const uint *src = (uint *) stmap + srcY * ps->region->pitch + x;
  97             GLint k;
  98             for (k = 0; k < width; k++) {
  99                values[k] = src[k] >> 24;
 100             }
 101          }
 102          break;
 103       case PIPE_FORMAT_Z24_S8:
 104          {
 105             const uint *src = (uint *) stmap + srcY * ps->region->pitch + x;
 106             GLint k;
 107             for (k = 0; k < width; k++) {
 108                values[k] = src[k] & 0xff;
 109             }
 110          }
 111          break;
 112       default:
 113          assert(0);
 114       }
 115
 116       /* store */
 117       dest = _mesa_image_address2d(packing, pixels, width, height,
 118                                    GL_STENCIL_INDEX, type, j, 0);
 119
 120       _mesa_pack_stencil_span(ctx, width, type, dest, values, packing);
 121    }
 122
 123
 124    /* unmap the stencil buffer */
 125    pipe->region_unmap(pipe, ps->region);
 126 }
 127
 128
 129
 130 /**
 131  * Do glReadPixels by getting rows from the framebuffer surface with
 132  * get_tile().  Convert to requested format/type with Mesa image routines.
 133  * Image transfer ops are done in software too.
 134  */
 135 static void
 136 st_readpixels(GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height,
 137               GLenum format, GLenum type,
 138               const struct gl_pixelstore_attrib *pack,
 139               GLvoid *dest)
 140 {
 141    struct pipe_context *pipe = ctx->st->pipe;
 142    GLfloat temp[MAX_WIDTH][4];
 143    const GLbitfield transferOps = ctx->_ImageTransferState;
 144    GLint i, yStep, dfStride;
 145    GLfloat *df;
 146    struct st_renderbuffer *strb;
 147    struct gl_pixelstore_attrib clippedPacking = *pack;
 148
 149    /* XXX convolution not done yet */
 150    assert((transferOps & IMAGE_CONVOLUTION_BIT) == 0);
 151
 152    /* Do all needed clipping here, so that we can forget about it later */
 153    if (!_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) {
 154       /* The ReadPixels region is totally outside the window bounds */
 155       return;
 156    }
 157
 158    /* make sure rendering has completed */
 159    pipe->flush(pipe, 0x0);
 160
 161    if (pack->BufferObj && pack->BufferObj->Name) {
 162       /* reading into a PBO */
 163
 164    }
 165    else {
 166       /* reading into user memory/buffer */
 167
 168    }
 169
 170    if (format == GL_STENCIL_INDEX) {
 171       st_read_stencil_pixels(ctx, x, y, width, height, type, pack, dest);
 172       return;
 173    }
 174    else if (format == GL_DEPTH_COMPONENT) {
 175       strb = st_renderbuffer(ctx->ReadBuffer->_DepthBuffer);
 176    }
 177    else {
 178       strb = st_renderbuffer(ctx->ReadBuffer->_ColorReadBuffer);
 179    }
 180    if (!strb)
 181       return;
 182
 183    pipe->region_map(pipe, strb->surface->region);
 184
 185    if (format == GL_RGBA && type == GL_FLOAT) {
 186       /* write tile(row) directly into user's buffer */
 187       df = (GLfloat *) _mesa_image_address2d(&clippedPacking, dest, width,
 188                                              height, format, type, 0, 0);
 189       dfStride = width * 4;
 190    }
 191 #if 0
 192    else if (format == GL_DEPTH_COMPONENT && type == GL_FLOAT) {
 193       /* write tile(row) directly into user's buffer */
 194       df = (GLfloat *) _mesa_image_address2d(&clippedPacking, dest, width,
 195                                              height, format, type, 0, 0);
 196       dfStride = width;
 197    }
 198 #endif
 199    else {
 200       /* write tile(row) into temp row buffer */
 201       df = (GLfloat *) temp;
 202       dfStride = 0;
 203    }
 204
 205    /* determine bottom-to-top vs. top-to-bottom order */
 206    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 207       y = strb->Base.Height - 1 - y;
 208       yStep = -1;
 209    }
 210    else {
 211       yStep = 1;
 212    }
 213
 214    /* Do a row at a time to flip image data vertically */
 215    for (i = 0; i < height; i++) {
 216       pipe->get_tile_rgba(pipe, strb->surface, x, y, width, 1, df);
 217       y += yStep;
 218       df += dfStride;
 219       if (!dfStride) {
 220          /* convert GLfloat to user's format/type */
 221          GLvoid *dst = _mesa_image_address2d(&clippedPacking, dest, width,
 222                                              height, format, type, i, 0);
 223          if (format == GL_DEPTH_COMPONENT) {
 224             _mesa_pack_depth_span(ctx, width, dst, type,
 225                                   (GLfloat *) temp, &clippedPacking);
 226          }
 227          else {
 228             _mesa_pack_rgba_span_float(ctx, width, temp, format, type, dst,
 229                                        &clippedPacking, transferOps);
 230          }
 231       }
 232    }
 233
 234    pipe->region_unmap(pipe, strb->surface->region);
 235 }
 236
 237
 238 void st_init_readpixels_functions(struct dd_function_table *functions)
 239 {
 240    functions->ReadPixels = st_readpixels;
 241 }