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/u_tile.h"
  45
  46 #include "st_context.h"
  47 #include "st_cb_bitmap.h"
  48 #include "st_cb_readpixels.h"
  49 #include "st_cb_fbo.h"
  50 #include "st_format.h"
  51 #include "st_public.h"
  52 #include "st_texture.h"
  53 #include "st_inlines.h"
  54
  55 /**
  56  * Special case for reading stencil buffer.
  57  * For color/depth we use get_tile().  For stencil, map the stencil buffer.
  58  */
  59 void
  60 st_read_stencil_pixels(GLcontext *ctx, GLint x, GLint y,
  61                        GLsizei width, GLsizei height,
  62                        GLenum format, GLenum type,
  63                        const struct gl_pixelstore_attrib *packing,
  64                        GLvoid *pixels)
  65 {
  66    struct gl_framebuffer *fb = ctx->ReadBuffer;
  67    struct pipe_screen *screen = ctx->st->pipe->screen;
  68    struct st_renderbuffer *strb = st_renderbuffer(fb->_StencilBuffer);
  69    struct pipe_transfer *pt;
  70    ubyte *stmap;
  71    GLint j;
  72
  73    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
  74       y = ctx->DrawBuffer->Height - y - height;
  75    }
  76
  77    /* Create a read transfer from the renderbuffer's texture */
  78
  79    pt = st_cond_flush_get_tex_transfer(st_context(ctx), strb->texture,
  80                                        0, 0, 0,
  81                                        PIPE_TRANSFER_READ, x, y,
  82                                        width, height);
  83
  84    /* map the stencil buffer */
  85    stmap = screen->transfer_map(screen, pt);
  86
  87    /* width should never be > MAX_WIDTH since we did clipping earlier */
  88    ASSERT(width <= MAX_WIDTH);
  89
  90    /* process image row by row */
  91    for (j = 0; j < height; j++) {
  92       GLvoid *dest;
  93       GLstencil sValues[MAX_WIDTH];
  94       GLfloat zValues[MAX_WIDTH];
  95       GLint srcY;
  96
  97       if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
  98          srcY = height - j - 1;
  99       }
 100       else {
 101          srcY = j;
 102       }
 103
 104       /* get stencil (and Z) values */
 105       switch (pt->format) {
 106       case PIPE_FORMAT_S8_UNORM:
 107          {
 108             const ubyte *src = stmap + srcY * pt->stride;
 109             memcpy(sValues, src, width);
 110          }
 111          break;
 112       case PIPE_FORMAT_S8Z24_UNORM:
 113          if (format == GL_DEPTH_STENCIL) {
 114             const uint *src = (uint *) (stmap + srcY * pt->stride);
 115             const GLfloat scale = 1.0f / (0xffffff);
 116             GLint k;
 117             for (k = 0; k < width; k++) {
 118                sValues[k] = src[k] >> 24;
 119                zValues[k] = (src[k] & 0xffffff) * scale;
 120             }
 121          }
 122          else {
 123             const uint *src = (uint *) (stmap + srcY * pt->stride);
 124             GLint k;
 125             for (k = 0; k < width; k++) {
 126                sValues[k] = src[k] >> 24;
 127             }
 128          }
 129          break;
 130       case PIPE_FORMAT_Z24S8_UNORM:
 131          if (format == GL_DEPTH_STENCIL) {
 132             const uint *src = (uint *) (stmap + srcY * pt->stride);
 133             const GLfloat scale = 1.0f / (0xffffff);
 134             GLint k;
 135             for (k = 0; k < width; k++) {
 136                sValues[k] = src[k] & 0xff;
 137                zValues[k] = (src[k] >> 8) * scale;
 138             }
 139          }
 140          else {
 141             const uint *src = (uint *) (stmap + srcY * pt->stride);
 142             GLint k;
 143             for (k = 0; k < width; k++) {
 144                sValues[k] = src[k] & 0xff;
 145             }
 146          }
 147          break;
 148       default:
 149          assert(0);
 150       }
 151
 152       /* store */
 153       dest = _mesa_image_address2d(packing, pixels, width, height,
 154                                    format, type, j, 0);
 155       if (format == GL_DEPTH_STENCIL) {
 156          _mesa_pack_depth_stencil_span(ctx, width, dest,
 157                                        zValues, sValues, packing);
 158       }
 159       else {
 160          _mesa_pack_stencil_span(ctx, width, type, dest, sValues, packing);
 161       }
 162    }
 163
 164    /* unmap the stencil buffer */
 165    screen->transfer_unmap(screen, pt);
 166    screen->tex_transfer_destroy(pt);
 167 }
 168
 169
 170 /**
 171  * Return renderbuffer to use for reading color pixels for glRead/CopyPixel
 172  * commands.
 173  * Special care is needed for the front buffer.
 174  */
 175 struct st_renderbuffer *
 176 st_get_color_read_renderbuffer(GLcontext *ctx)
 177 {
 178    struct gl_framebuffer *fb = ctx->ReadBuffer;
 179    struct st_renderbuffer *strb =
 180       st_renderbuffer(fb->_ColorReadBuffer);
 181    struct st_renderbuffer *front =
 182       st_renderbuffer(fb->Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
 183
 184    if (strb == front
 185        && ctx->st->frontbuffer_status == FRONT_STATUS_COPY_OF_BACK) {
 186       /* reading from front color buffer, which is a logical copy of the
 187        * back color buffer.
 188        */
 189       struct st_renderbuffer *back =
 190          st_renderbuffer(fb->Attachment[BUFFER_BACK_LEFT].Renderbuffer);
 191       strb = back;
 192    }
 193
 194    return strb;
 195 }
 196
 197
 198 /**
 199  * Try to do glReadPixels in a fast manner for common cases.
 200  * \return GL_TRUE for success, GL_FALSE for failure
 201  */
 202 static GLboolean
 203 st_fast_readpixels(GLcontext *ctx, struct st_renderbuffer *strb,
 204                    GLint x, GLint y, GLsizei width, GLsizei height,
 205                    GLenum format, GLenum type,
 206                    const struct gl_pixelstore_attrib *pack,
 207                    GLvoid *dest)
 208 {
 209    enum combination {
 210       A8R8G8B8_UNORM_TO_RGBA_UBYTE,
 211       A8R8G8B8_UNORM_TO_RGB_UBYTE,
 212       A8R8G8B8_UNORM_TO_BGRA_UINT
 213    } combo;
 214
 215    if (ctx->_ImageTransferState)
 216       return GL_FALSE;
 217
 218    if (strb->format == PIPE_FORMAT_A8R8G8B8_UNORM &&
 219        format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
 220       combo = A8R8G8B8_UNORM_TO_RGBA_UBYTE;
 221    }
 222    else if (strb->format == PIPE_FORMAT_A8R8G8B8_UNORM &&
 223             format == GL_RGB && type == GL_UNSIGNED_BYTE) {
 224       combo = A8R8G8B8_UNORM_TO_RGB_UBYTE;
 225    }
 226    else if (strb->format == PIPE_FORMAT_A8R8G8B8_UNORM &&
 227             format == GL_BGRA && type == GL_UNSIGNED_INT_8_8_8_8_REV) {
 228       combo = A8R8G8B8_UNORM_TO_BGRA_UINT;
 229    }
 230    else {
 231       return GL_FALSE;
 232    }
 233
 234    /*printf("st_fast_readpixels combo %d\n", (GLint) combo);*/
 235
 236    {
 237       struct pipe_context *pipe = ctx->st->pipe;
 238       struct pipe_screen *screen = pipe->screen;
 239       struct pipe_transfer *trans;
 240       const GLubyte *map;
 241       GLubyte *dst;
 242       GLint row, col, dy, dstStride;
 243
 244       if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 245          y = strb->texture->height[0] - y - height;
 246       }
 247
 248       trans = st_cond_flush_get_tex_transfer(st_context(ctx), strb->texture,
 249                                              0, 0, 0,
 250                                              PIPE_TRANSFER_READ, x, y,
 251                                              width, height);
 252       if (!trans) {
 253          return GL_FALSE;
 254       }
 255
 256       map = screen->transfer_map(screen, trans);
 257       if (!map) {
 258          screen->tex_transfer_destroy(trans);
 259          return GL_FALSE;
 260       }
 261
 262       if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 263          y = height - 1;
 264          dy = -1;
 265       }
 266       else {
 267          y = 0;
 268          dy = 1;
 269       }
 270
 271       dst = _mesa_image_address2d(pack, dest, width, height,
 272                                   format, type, 0, 0);
 273       dstStride = _mesa_image_row_stride(pack, width, format, type);
 274
 275       switch (combo) {
 276       case A8R8G8B8_UNORM_TO_RGBA_UBYTE:
 277          for (row = 0; row < height; row++) {
 278             const GLubyte *src = map + y * trans->stride;
 279             for (col = 0; col < width; col++) {
 280                GLuint pixel = ((GLuint *) src)[col];
 281                dst[col*4+0] = (pixel >> 16) & 0xff;
 282                dst[col*4+1] = (pixel >>  8) & 0xff;
 283                dst[col*4+2] = (pixel >>  0) & 0xff;
 284                dst[col*4+3] = (pixel >> 24) & 0xff;
 285             }
 286             dst += dstStride;
 287             y += dy;
 288          }
 289          break;
 290       case A8R8G8B8_UNORM_TO_RGB_UBYTE:
 291          for (row = 0; row < height; row++) {
 292             const GLubyte *src = map + y * trans->stride;
 293             for (col = 0; col < width; col++) {
 294                GLuint pixel = ((GLuint *) src)[col];
 295                dst[col*3+0] = (pixel >> 16) & 0xff;
 296                dst[col*3+1] = (pixel >>  8) & 0xff;
 297                dst[col*3+2] = (pixel >>  0) & 0xff;
 298             }
 299             dst += dstStride;
 300             y += dy;
 301          }
 302          break;
 303       case A8R8G8B8_UNORM_TO_BGRA_UINT:
 304          for (row = 0; row < height; row++) {
 305             const GLubyte *src = map + y * trans->stride;
 306             memcpy(dst, src, 4 * width);
 307             dst += dstStride;
 308             y += dy;
 309          }
 310          break;
 311       default:
 312          ; /* nothing */
 313       }
 314
 315       screen->transfer_unmap(screen, trans);
 316       screen->tex_transfer_destroy(trans);
 317    }
 318
 319    return GL_TRUE;
 320 }
 321
 322
 323 /**
 324  * Do glReadPixels by getting rows from the framebuffer transfer with
 325  * get_tile().  Convert to requested format/type with Mesa image routines.
 326  * Image transfer ops are done in software too.
 327  */
 328 static void
 329 st_readpixels(GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height,
 330               GLenum format, GLenum type,
 331               const struct gl_pixelstore_attrib *pack,
 332               GLvoid *dest)
 333 {
 334    struct pipe_context *pipe = ctx->st->pipe;
 335    struct pipe_screen *screen = pipe->screen;
 336    GLfloat temp[MAX_WIDTH][4];
 337    const GLbitfield transferOps = ctx->_ImageTransferState;
 338    GLsizei i, j;
 339    GLint yStep, dfStride;
 340    GLfloat *df;
 341    struct st_renderbuffer *strb;
 342    struct gl_pixelstore_attrib clippedPacking = *pack;
 343    struct pipe_transfer *trans;
 344
 345    assert(ctx->ReadBuffer->Width > 0);
 346
 347    /* XXX convolution not done yet */
 348    assert((transferOps & IMAGE_CONVOLUTION_BIT) == 0);
 349
 350    /* Do all needed clipping here, so that we can forget about it later */
 351    if (!_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) {
 352       /* The ReadPixels transfer is totally outside the window bounds */
 353       return;
 354    }
 355
 356    dest = _mesa_map_pbo_dest(ctx, &clippedPacking, dest);
 357    if (!dest)
 358       return;
 359
 360    st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL);
 361
 362    if (format == GL_STENCIL_INDEX ||
 363        format == GL_DEPTH_STENCIL) {
 364       st_read_stencil_pixels(ctx, x, y, width, height,
 365                              format, type, pack, dest);
 366       return;
 367    }
 368    else if (format == GL_DEPTH_COMPONENT) {
 369       strb = st_renderbuffer(ctx->ReadBuffer->_DepthBuffer);
 370    }
 371    else {
 372       /* Read color buffer */
 373       strb = st_get_color_read_renderbuffer(ctx);
 374    }
 375
 376    if (!strb)
 377       return;
 378
 379    /* try a fast-path readpixels before anything else */
 380    if (st_fast_readpixels(ctx, strb, x, y, width, height,
 381                           format, type, pack, dest)) {
 382       /* success! */
 383       _mesa_unmap_pbo_dest(ctx, &clippedPacking);
 384       return;
 385    }
 386
 387    if (format == GL_RGBA && type == GL_FLOAT) {
 388       /* write tile(row) directly into user's buffer */
 389       df = (GLfloat *) _mesa_image_address2d(&clippedPacking, dest, width,
 390                                              height, format, type, 0, 0);
 391       dfStride = width * 4;
 392    }
 393    else {
 394       /* write tile(row) into temp row buffer */
 395       df = (GLfloat *) temp;
 396       dfStride = 0;
 397    }
 398
 399    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 400       y = strb->Base.Height - y - height;
 401    }
 402
 403    /* Create a read transfer from the renderbuffer's texture */
 404    trans = st_cond_flush_get_tex_transfer(st_context(ctx), strb->texture,
 405                                           0, 0, 0,
 406                                           PIPE_TRANSFER_READ, x, y,
 407                                           width, height);
 408
 409    /* determine bottom-to-top vs. top-to-bottom order */
 410    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 411       y = height - 1;
 412       yStep = -1;
 413    }
 414    else {
 415       y = 0;
 416       yStep = 1;
 417    }
 418
 419    /*
 420     * Copy pixels from pipe_transfer to user memory
 421     */
 422    {
 423       /* dest of first pixel in client memory */
 424       GLubyte *dst = _mesa_image_address2d(&clippedPacking, dest, width,
 425                                            height, format, type, 0, 0);
 426       /* dest row stride */
 427       const GLint dstStride = _mesa_image_row_stride(&clippedPacking, width,
 428                                                      format, type);
 429
 430       if (trans->format == PIPE_FORMAT_S8Z24_UNORM ||
 431           trans->format == PIPE_FORMAT_X8Z24_UNORM) {
 432          if (format == GL_DEPTH_COMPONENT) {
 433             for (i = 0; i < height; i++) {
 434                GLuint ztemp[MAX_WIDTH];
 435                GLfloat zfloat[MAX_WIDTH];
 436                const double scale = 1.0 / ((1 << 24) - 1);
 437                pipe_get_tile_raw(trans, 0, y, width, 1, ztemp, 0);
 438                y += yStep;
 439                for (j = 0; j < width; j++) {
 440                   zfloat[j] = (float) (scale * (ztemp[j] & 0xffffff));
 441                }
 442                _mesa_pack_depth_span(ctx, width, dst, type,
 443                                      zfloat, &clippedPacking);
 444                dst += dstStride;
 445             }
 446          }
 447          else {
 448             /* XXX: unreachable code -- should be before st_read_stencil_pixels */
 449             assert(format == GL_DEPTH_STENCIL_EXT);
 450             for (i = 0; i < height; i++) {
 451                GLuint *zshort = (GLuint *)dst;
 452                pipe_get_tile_raw(trans, 0, y, width, 1, dst, 0);
 453                y += yStep;
 454                /* Reverse into 24/8 */
 455                for (j = 0; j < width; j++) {
 456                   zshort[j] = (zshort[j] << 8) | (zshort[j] >> 24);
 457                }
 458                dst += dstStride;
 459             }
 460          }
 461       }
 462       else if (trans->format == PIPE_FORMAT_Z24S8_UNORM ||
 463                trans->format == PIPE_FORMAT_Z24X8_UNORM) {
 464          if (format == GL_DEPTH_COMPONENT) {
 465             for (i = 0; i < height; i++) {
 466                GLuint ztemp[MAX_WIDTH];
 467                GLfloat zfloat[MAX_WIDTH];
 468                const double scale = 1.0 / ((1 << 24) - 1);
 469                pipe_get_tile_raw(trans, 0, y, width, 1, ztemp, 0);
 470                y += yStep;
 471                for (j = 0; j < width; j++) {
 472                   zfloat[j] = (float) (scale * ((ztemp[j] >> 8) & 0xffffff));
 473                }
 474                _mesa_pack_depth_span(ctx, width, dst, type,
 475                                      zfloat, &clippedPacking);
 476                dst += dstStride;
 477             }
 478          }
 479          else {
 480             /* XXX: unreachable code -- should be before st_read_stencil_pixels */
 481             assert(format == GL_DEPTH_STENCIL_EXT);
 482             for (i = 0; i < height; i++) {
 483                pipe_get_tile_raw(trans, 0, y, width, 1, dst, 0);
 484                y += yStep;
 485                dst += dstStride;
 486             }
 487          }
 488       }
 489       else if (trans->format == PIPE_FORMAT_Z16_UNORM) {
 490          for (i = 0; i < height; i++) {
 491             GLushort ztemp[MAX_WIDTH];
 492             GLfloat zfloat[MAX_WIDTH];
 493             const double scale = 1.0 / 0xffff;
 494             pipe_get_tile_raw(trans, 0, y, width, 1, ztemp, 0);
 495             y += yStep;
 496             for (j = 0; j < width; j++) {
 497                zfloat[j] = (float) (scale * ztemp[j]);
 498             }
 499             _mesa_pack_depth_span(ctx, width, dst, type,
 500                                   zfloat, &clippedPacking);
 501             dst += dstStride;
 502          }
 503       }
 504       else if (trans->format == PIPE_FORMAT_Z32_UNORM) {
 505          for (i = 0; i < height; i++) {
 506             GLuint ztemp[MAX_WIDTH];
 507             GLfloat zfloat[MAX_WIDTH];
 508             const double scale = 1.0 / 0xffffffff;
 509             pipe_get_tile_raw(trans, 0, y, width, 1, ztemp, 0);
 510             y += yStep;
 511             for (j = 0; j < width; j++) {
 512                zfloat[j] = (float) (scale * ztemp[j]);
 513             }
 514             _mesa_pack_depth_span(ctx, width, dst, type,
 515                                   zfloat, &clippedPacking);
 516             dst += dstStride;
 517          }
 518       }
 519       else {
 520          /* RGBA format */
 521          /* Do a row at a time to flip image data vertically */
 522          for (i = 0; i < height; i++) {
 523             pipe_get_tile_rgba(trans, 0, y, width, 1, df);
 524             y += yStep;
 525             df += dfStride;
 526             if (!dfStride) {
 527                _mesa_pack_rgba_span_float(ctx, width, temp, format, type, dst,
 528                                           &clippedPacking, transferOps);
 529                dst += dstStride;
 530             }
 531          }
 532       }
 533    }
 534
 535    screen->tex_transfer_destroy(trans);
 536
 537    _mesa_unmap_pbo_dest(ctx, &clippedPacking);
 538 }
 539
 540
 541 void st_init_readpixels_functions(struct dd_function_table *functions)
 542 {
 543    functions->ReadPixels = st_readpixels;
 544 }