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/bufferobj.h"
  38 #include "main/context.h"
  39 #include "main/image.h"
  40
  41 #include "pipe/p_context.h"
  42 #include "pipe/p_defines.h"
  43 #include "pipe/p_inlines.h"
  44 #include "util/p_tile.h"
  45 #include "st_context.h"
  46 #include "st_cb_bitmap.h"
  47 #include "st_cb_readpixels.h"
  48 #include "st_cb_fbo.h"
  49 #include "st_format.h"
  50 #include "st_public.h"
  51
  52
  53 /**
  54  * Special case for reading stencil buffer.
  55  * For color/depth we use get_tile().  For stencil, map the stencil buffer.
  56  */
  57 void
  58 st_read_stencil_pixels(GLcontext *ctx, GLint x, GLint y,
  59                        GLsizei width, GLsizei height, GLenum type,
  60                        const struct gl_pixelstore_attrib *packing,
  61                        GLvoid *pixels)
  62 {
  63    struct gl_framebuffer *fb = ctx->ReadBuffer;
  64    struct st_renderbuffer *strb = st_renderbuffer(fb->_StencilBuffer);
  65    struct pipe_surface *ps = strb->surface;
  66    ubyte *stmap;
  67    GLint j;
  68
  69    /* map the stencil buffer */
  70    stmap = pipe_surface_map(ps);
  71
  72    /* width should never be > MAX_WIDTH since we did clipping earlier */
  73    ASSERT(width <= MAX_WIDTH);
  74
  75    /* process image row by row */
  76    for (j = 0; j < height; j++, y++) {
  77       GLvoid *dest;
  78       GLstencil values[MAX_WIDTH];
  79       GLint srcY;
  80
  81       if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
  82          srcY = ctx->DrawBuffer->Height - y - 1;
  83       }
  84       else {
  85          srcY = y;
  86       }
  87
  88       /* get stencil values */
  89       switch (ps->format) {
  90       case PIPE_FORMAT_S8_UNORM:
  91          {
  92             const ubyte *src = stmap + srcY * ps->pitch + x;
  93             memcpy(values, src, width);
  94          }
  95          break;
  96       case PIPE_FORMAT_S8Z24_UNORM:
  97          {
  98             const uint *src = (uint *) stmap + srcY * ps->pitch + x;
  99             GLint k;
 100             for (k = 0; k < width; k++) {
 101                values[k] = src[k] >> 24;
 102             }
 103          }
 104          break;
 105       case PIPE_FORMAT_Z24S8_UNORM:
 106          {
 107             const uint *src = (uint *) stmap + srcY * ps->pitch + x;
 108             GLint k;
 109             for (k = 0; k < width; k++) {
 110                values[k] = src[k] & 0xff;
 111             }
 112          }
 113          break;
 114       default:
 115          assert(0);
 116       }
 117
 118       /* store */
 119       dest = _mesa_image_address2d(packing, pixels, width, height,
 120                                    GL_STENCIL_INDEX, type, j, 0);
 121
 122       _mesa_pack_stencil_span(ctx, width, type, dest, values, packing);
 123    }
 124
 125
 126    /* unmap the stencil buffer */
 127    pipe_surface_unmap(ps);
 128 }
 129
 130
 131 /**
 132  * Return renderbuffer to use for reading color pixels for glRead/CopyPixel
 133  * commands.
 134  * Special care is needed for the front buffer.
 135  */
 136 struct st_renderbuffer *
 137 st_get_color_read_renderbuffer(GLcontext *ctx)
 138 {
 139    struct gl_framebuffer *fb = ctx->ReadBuffer;
 140    struct st_renderbuffer *strb =
 141       st_renderbuffer(fb->_ColorReadBuffer);
 142    struct st_renderbuffer *front =
 143       st_renderbuffer(fb->Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
 144
 145    if (strb == front
 146        && ctx->st->frontbuffer_status == FRONT_STATUS_COPY_OF_BACK) {
 147       /* reading from front color buffer, which is a logical copy of the
 148        * back color buffer.
 149        */
 150       struct st_renderbuffer *back =
 151          st_renderbuffer(fb->Attachment[BUFFER_BACK_LEFT].Renderbuffer);
 152       strb = back;
 153    }
 154
 155    return strb;
 156 }
 157
 158
 159 /**
 160  * Do glReadPixels by getting rows from the framebuffer surface with
 161  * get_tile().  Convert to requested format/type with Mesa image routines.
 162  * Image transfer ops are done in software too.
 163  */
 164 static void
 165 st_readpixels(GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height,
 166               GLenum format, GLenum type,
 167               const struct gl_pixelstore_attrib *pack,
 168               GLvoid *dest)
 169 {
 170    struct pipe_context *pipe = ctx->st->pipe;
 171    GLfloat temp[MAX_WIDTH][4];
 172    const GLbitfield transferOps = ctx->_ImageTransferState;
 173    GLint i, yStep, dfStride;
 174    GLfloat *df;
 175    struct st_renderbuffer *strb;
 176    struct gl_pixelstore_attrib clippedPacking = *pack;
 177
 178    /* XXX convolution not done yet */
 179    assert((transferOps & IMAGE_CONVOLUTION_BIT) == 0);
 180
 181    /* Do all needed clipping here, so that we can forget about it later */
 182    if (!_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) {
 183       /* The ReadPixels surface is totally outside the window bounds */
 184       return;
 185    }
 186
 187    dest = _mesa_map_readpix_pbo(ctx, &clippedPacking, dest);
 188    if (!dest)
 189       return;
 190
 191    st_flush_bitmap_cache(ctx->st);
 192
 193    /* make sure rendering has completed */
 194    pipe->flush(pipe, PIPE_FLUSH_RENDER_CACHE, NULL);
 195
 196    if (format == GL_STENCIL_INDEX) {
 197       st_read_stencil_pixels(ctx, x, y, width, height, type, pack, dest);
 198       return;
 199    }
 200    else if (format == GL_DEPTH_COMPONENT) {
 201       strb = st_renderbuffer(ctx->ReadBuffer->_DepthBuffer);
 202    }
 203    else {
 204       /* Read color buffer */
 205       strb = st_get_color_read_renderbuffer(ctx);
 206    }
 207
 208    if (!strb)
 209       return;
 210
 211    if (format == GL_RGBA && type == GL_FLOAT) {
 212       /* write tile(row) directly into user's buffer */
 213       df = (GLfloat *) _mesa_image_address2d(&clippedPacking, dest, width,
 214                                              height, format, type, 0, 0);
 215       dfStride = width * 4;
 216    }
 217    else {
 218       /* write tile(row) into temp row buffer */
 219       df = (GLfloat *) temp;
 220       dfStride = 0;
 221    }
 222
 223    /* determine bottom-to-top vs. top-to-bottom order */
 224    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 225       y = strb->Base.Height - 1 - y;
 226       yStep = -1;
 227    }
 228    else {
 229       yStep = 1;
 230    }
 231
 232    /*
 233     * Copy pixels from pipe_surface to user memory
 234     */
 235    {
 236       /* dest of first pixel in client memory */
 237       GLubyte *dst = _mesa_image_address2d(&clippedPacking, dest, width,
 238                                            height, format, type, 0, 0);
 239       /* dest row stride */
 240       const GLint dstStride = _mesa_image_row_stride(&clippedPacking, width,
 241                                                      format, type);
 242
 243       if (strb->surface->format == PIPE_FORMAT_S8Z24_UNORM ||
 244           strb->surface->format == PIPE_FORMAT_X8Z24_UNORM) {
 245          if (format == GL_DEPTH_COMPONENT) {
 246             for (i = 0; i < height; i++) {
 247                GLuint ztemp[MAX_WIDTH], j;
 248                GLfloat zfloat[MAX_WIDTH];
 249                const double scale = 1.0 / ((1 << 24) - 1);
 250                pipe_get_tile_raw(pipe, strb->surface, x, y,
 251                                  width, 1, ztemp, 0);
 252                y += yStep;
 253                for (j = 0; j < width; j++) {
 254                   zfloat[j] = (float) (scale * (ztemp[j] & 0xffffff));
 255                }
 256                _mesa_pack_depth_span(ctx, width, dst, type,
 257                                      zfloat, &clippedPacking);
 258                dst += dstStride;
 259             }
 260          }
 261          else {
 262             /* untested, but simple: */
 263             assert(format == GL_DEPTH_STENCIL_EXT);
 264             for (i = 0; i < height; i++) {
 265                pipe_get_tile_raw(pipe, strb->surface, x, y, width, 1, dst, 0);
 266                y += yStep;
 267                dst += dstStride;
 268             }
 269          }
 270       }
 271       else if (strb->surface->format == PIPE_FORMAT_Z16_UNORM) {
 272          for (i = 0; i < height; i++) {
 273             GLushort ztemp[MAX_WIDTH], j;
 274             GLfloat zfloat[MAX_WIDTH];
 275             const double scale = 1.0 / 0xffff;
 276             pipe_get_tile_raw(pipe, strb->surface, x, y, width, 1, ztemp, 0);
 277             y += yStep;
 278             for (j = 0; j < width; j++) {
 279                zfloat[j] = (float) (scale * ztemp[j]);
 280             }
 281             _mesa_pack_depth_span(ctx, width, dst, type,
 282                                   zfloat, &clippedPacking);
 283             dst += dstStride;
 284          }
 285       }
 286       else if (strb->surface->format == PIPE_FORMAT_Z32_UNORM) {
 287          for (i = 0; i < height; i++) {
 288             GLuint ztemp[MAX_WIDTH], j;
 289             GLfloat zfloat[MAX_WIDTH];
 290             const double scale = 1.0 / 0xffffffff;
 291             pipe_get_tile_raw(pipe, strb->surface, x, y, width, 1, ztemp, 0);
 292             y += yStep;
 293             for (j = 0; j < width; j++) {
 294                zfloat[j] = (float) (scale * ztemp[j]);
 295             }
 296             _mesa_pack_depth_span(ctx, width, dst, type,
 297                                   zfloat, &clippedPacking);
 298             dst += dstStride;
 299          }
 300       }
 301       else {
 302          /* RGBA format */
 303          /* Do a row at a time to flip image data vertically */
 304          for (i = 0; i < height; i++) {
 305             pipe_get_tile_rgba(pipe, strb->surface, x, y, width, 1, df);
 306             y += yStep;
 307             df += dfStride;
 308             if (!dfStride) {
 309                _mesa_pack_rgba_span_float(ctx, width, temp, format, type, dst,
 310                                           &clippedPacking, transferOps);
 311                dst += dstStride;
 312             }
 313          }
 314       }
 315    }
 316
 317    _mesa_unmap_readpix_pbo(ctx, &clippedPacking);
 318 }
 319
 320
 321 void st_init_readpixels_functions(struct dd_function_table *functions)
 322 {
 323    functions->ReadPixels = st_readpixels;
 324 }