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 pipe_screen *screen = ctx->st->pipe->screen;
  65    struct st_renderbuffer *strb = st_renderbuffer(fb->_StencilBuffer);
  66    struct pipe_surface *ps;
  67    ubyte *stmap;
  68    GLint j;
  69
  70    /* Create a CPU-READ surface/view into the renderbuffer's texture */
  71    ps = screen->get_tex_surface(screen, strb->texture,  0, 0, 0,
  72                                 PIPE_BUFFER_USAGE_CPU_READ);
  73
  74    /* map the stencil buffer */
  75    stmap = screen->surface_map(screen, ps, PIPE_BUFFER_USAGE_CPU_READ);
  76
  77    /* width should never be > MAX_WIDTH since we did clipping earlier */
  78    ASSERT(width <= MAX_WIDTH);
  79
  80    /* process image row by row */
  81    for (j = 0; j < height; j++, y++) {
  82       GLvoid *dest;
  83       GLstencil values[MAX_WIDTH];
  84       GLint srcY;
  85
  86       if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
  87          srcY = ctx->DrawBuffer->Height - y - 1;
  88       }
  89       else {
  90          srcY = y;
  91       }
  92
  93       /* get stencil values */
  94       switch (ps->format) {
  95       case PIPE_FORMAT_U_S8:
  96          {
  97             const ubyte *src = stmap + srcY * ps->pitch + x;
  98             memcpy(values, src, width);
  99          }
 100          break;
 101       case PIPE_FORMAT_S8Z24_UNORM:
 102          {
 103             const uint *src = (uint *) stmap + srcY * ps->pitch + x;
 104             GLint k;
 105             for (k = 0; k < width; k++) {
 106                values[k] = src[k] >> 24;
 107             }
 108          }
 109          break;
 110       case PIPE_FORMAT_Z24S8_UNORM:
 111          {
 112             const uint *src = (uint *) stmap + srcY * ps->pitch + x;
 113             GLint k;
 114             for (k = 0; k < width; k++) {
 115                values[k] = src[k] & 0xff;
 116             }
 117          }
 118          break;
 119       default:
 120          assert(0);
 121       }
 122
 123       /* store */
 124       dest = _mesa_image_address2d(packing, pixels, width, height,
 125                                    GL_STENCIL_INDEX, type, j, 0);
 126
 127       _mesa_pack_stencil_span(ctx, width, type, dest, values, packing);
 128    }
 129
 130
 131    /* unmap the stencil buffer */
 132    screen->surface_unmap(screen, ps);
 133    pipe_surface_reference(&ps, NULL);
 134 }
 135
 136
 137 /**
 138  * Return renderbuffer to use for reading color pixels for glRead/CopyPixel
 139  * commands.
 140  * Special care is needed for the front buffer.
 141  */
 142 struct st_renderbuffer *
 143 st_get_color_read_renderbuffer(GLcontext *ctx)
 144 {
 145    struct gl_framebuffer *fb = ctx->ReadBuffer;
 146    struct st_renderbuffer *strb =
 147       st_renderbuffer(fb->_ColorReadBuffer);
 148    struct st_renderbuffer *front =
 149       st_renderbuffer(fb->Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
 150
 151    if (strb == front
 152        && ctx->st->frontbuffer_status == FRONT_STATUS_COPY_OF_BACK) {
 153       /* reading from front color buffer, which is a logical copy of the
 154        * back color buffer.
 155        */
 156       struct st_renderbuffer *back =
 157          st_renderbuffer(fb->Attachment[BUFFER_BACK_LEFT].Renderbuffer);
 158       strb = back;
 159    }
 160
 161    return strb;
 162 }
 163
 164
 165 /**
 166  * Do glReadPixels by getting rows from the framebuffer surface with
 167  * get_tile().  Convert to requested format/type with Mesa image routines.
 168  * Image transfer ops are done in software too.
 169  */
 170 static void
 171 st_readpixels(GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height,
 172               GLenum format, GLenum type,
 173               const struct gl_pixelstore_attrib *pack,
 174               GLvoid *dest)
 175 {
 176    struct pipe_context *pipe = ctx->st->pipe;
 177    struct pipe_screen *screen = pipe->screen;
 178    GLfloat temp[MAX_WIDTH][4];
 179    const GLbitfield transferOps = ctx->_ImageTransferState;
 180    GLint i, yStep, dfStride;
 181    GLfloat *df;
 182    struct st_renderbuffer *strb;
 183    struct gl_pixelstore_attrib clippedPacking = *pack;
 184    struct pipe_surface *surf;
 185
 186    assert(ctx->ReadBuffer->Width > 0);
 187
 188    /* XXX convolution not done yet */
 189    assert((transferOps & IMAGE_CONVOLUTION_BIT) == 0);
 190
 191    /* Do all needed clipping here, so that we can forget about it later */
 192    if (!_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) {
 193       /* The ReadPixels surface is totally outside the window bounds */
 194       return;
 195    }
 196
 197    dest = _mesa_map_readpix_pbo(ctx, &clippedPacking, dest);
 198    if (!dest)
 199       return;
 200
 201    st_flush_bitmap_cache(ctx->st);
 202
 203    /* make sure rendering has completed */
 204    pipe->flush(pipe, PIPE_FLUSH_RENDER_CACHE, NULL);
 205
 206    if (format == GL_STENCIL_INDEX) {
 207       st_read_stencil_pixels(ctx, x, y, width, height, type, pack, dest);
 208       return;
 209    }
 210    else if (format == GL_DEPTH_COMPONENT) {
 211       strb = st_renderbuffer(ctx->ReadBuffer->_DepthBuffer);
 212    }
 213    else {
 214       /* Read color buffer */
 215       strb = st_get_color_read_renderbuffer(ctx);
 216    }
 217
 218    if (!strb)
 219       return;
 220
 221    if (format == GL_RGBA && type == GL_FLOAT) {
 222       /* write tile(row) directly into user's buffer */
 223       df = (GLfloat *) _mesa_image_address2d(&clippedPacking, dest, width,
 224                                              height, format, type, 0, 0);
 225       dfStride = width * 4;
 226    }
 227    else {
 228       /* write tile(row) into temp row buffer */
 229       df = (GLfloat *) temp;
 230       dfStride = 0;
 231    }
 232
 233    /* determine bottom-to-top vs. top-to-bottom order */
 234    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 235       y = strb->Base.Height - 1 - y;
 236       yStep = -1;
 237    }
 238    else {
 239       yStep = 1;
 240    }
 241
 242    /* Create a CPU-READ surface/view into the renderbuffer's texture */
 243    surf = screen->get_tex_surface(screen, strb->texture,  0, 0, 0,
 244                                   PIPE_BUFFER_USAGE_CPU_READ);
 245
 246    /*
 247     * Copy pixels from pipe_surface to user memory
 248     */
 249    {
 250       /* dest of first pixel in client memory */
 251       GLubyte *dst = _mesa_image_address2d(&clippedPacking, dest, width,
 252                                            height, format, type, 0, 0);
 253       /* dest row stride */
 254       const GLint dstStride = _mesa_image_row_stride(&clippedPacking, width,
 255                                                      format, type);
 256
 257       if (surf->format == PIPE_FORMAT_S8Z24_UNORM ||
 258           surf->format == PIPE_FORMAT_X8Z24_UNORM) {
 259          if (format == GL_DEPTH_COMPONENT) {
 260             for (i = 0; i < height; i++) {
 261                GLuint ztemp[MAX_WIDTH], j;
 262                GLfloat zfloat[MAX_WIDTH];
 263                const double scale = 1.0 / ((1 << 24) - 1);
 264                pipe_get_tile_raw(pipe, surf, x, y, width, 1, ztemp, 0);
 265                y += yStep;
 266                for (j = 0; j < width; j++) {
 267                   zfloat[j] = (float) (scale * (ztemp[j] & 0xffffff));
 268                }
 269                _mesa_pack_depth_span(ctx, width, dst, type,
 270                                      zfloat, &clippedPacking);
 271                dst += dstStride;
 272             }
 273          }
 274          else {
 275             /* untested, but simple: */
 276             assert(format == GL_DEPTH_STENCIL_EXT);
 277             for (i = 0; i < height; i++) {
 278                pipe_get_tile_raw(pipe, surf, x, y, width, 1, dst, 0);
 279                y += yStep;
 280                dst += dstStride;
 281             }
 282          }
 283       }
 284       else if (surf->format == PIPE_FORMAT_Z16_UNORM) {
 285          for (i = 0; i < height; i++) {
 286             GLushort ztemp[MAX_WIDTH], j;
 287             GLfloat zfloat[MAX_WIDTH];
 288             const double scale = 1.0 / 0xffff;
 289             pipe_get_tile_raw(pipe, surf, x, y, width, 1, ztemp, 0);
 290             y += yStep;
 291             for (j = 0; j < width; j++) {
 292                zfloat[j] = (float) (scale * ztemp[j]);
 293             }
 294             _mesa_pack_depth_span(ctx, width, dst, type,
 295                                   zfloat, &clippedPacking);
 296             dst += dstStride;
 297          }
 298       }
 299       else if (surf->format == PIPE_FORMAT_Z32_UNORM) {
 300          for (i = 0; i < height; i++) {
 301             GLuint ztemp[MAX_WIDTH], j;
 302             GLfloat zfloat[MAX_WIDTH];
 303             const double scale = 1.0 / 0xffffffff;
 304             pipe_get_tile_raw(pipe, surf, x, y, width, 1, ztemp, 0);
 305             y += yStep;
 306             for (j = 0; j < width; j++) {
 307                zfloat[j] = (float) (scale * ztemp[j]);
 308             }
 309             _mesa_pack_depth_span(ctx, width, dst, type,
 310                                   zfloat, &clippedPacking);
 311             dst += dstStride;
 312          }
 313       }
 314       else {
 315          /* RGBA format */
 316          /* Do a row at a time to flip image data vertically */
 317          for (i = 0; i < height; i++) {
 318             pipe_get_tile_rgba(pipe, surf, x, y, width, 1, df);
 319             y += yStep;
 320             df += dfStride;
 321             if (!dfStride) {
 322                _mesa_pack_rgba_span_float(ctx, width, temp, format, type, dst,
 323                                           &clippedPacking, transferOps);
 324                dst += dstStride;
 325             }
 326          }
 327       }
 328    }
 329
 330    pipe_surface_reference(&surf, NULL);
 331
 332    _mesa_unmap_readpix_pbo(ctx, &clippedPacking);
 333 }
 334
 335
 336 void st_init_readpixels_functions(struct dd_function_table *functions)
 337 {
 338    functions->ReadPixels = st_readpixels;
 339 }