src/mesa/swrast/s_texture.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 2011 VMware, Inc.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  20  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * Functions for mapping/unmapping texture images.
  26  */
  27
  28
  29 #include "main/context.h"
  30 #include "main/fbobject.h"
  31 #include "main/teximage.h"
  32 #include "swrast/swrast.h"
  33 #include "swrast/s_context.h"
  34
  35
  36 /**
  37  * Allocate a new swrast_texture_image (a subclass of gl_texture_image).
  38  * Called via ctx->Driver.NewTextureImage().
  39  */
  40 struct gl_texture_image *
  41 _swrast_new_texture_image( struct gl_context *ctx )
  42 {
  43    (void) ctx;
  44    return (struct gl_texture_image *) CALLOC_STRUCT(swrast_texture_image);
  45 }
  46
  47
  48 /**
  49  * Free a swrast_texture_image (a subclass of gl_texture_image).
  50  * Called via ctx->Driver.DeleteTextureImage().
  51  */
  52 void
  53 _swrast_delete_texture_image(struct gl_context *ctx,
  54                              struct gl_texture_image *texImage)
  55 {
  56    /* Nothing special for the subclass yet */
  57    _mesa_delete_texture_image(ctx, texImage);
  58 }
  59
  60
  61 /**
  62  * Error checking for debugging only.
  63  */
  64 static void
  65 _mesa_check_map_teximage(struct gl_texture_image *texImage,
  66                          GLuint slice, GLuint x, GLuint y, GLuint w, GLuint h)
  67 {
  68
  69    if (texImage->TexObject->Target == GL_TEXTURE_1D)
  70       assert(y == 0 && h == 1);
  71
  72    assert(x < texImage->Width || texImage->Width == 0);
  73    assert(y < texImage->Height || texImage->Height == 0);
  74    assert(x + w <= texImage->Width);
  75    assert(y + h <= texImage->Height);
  76 }
  77
  78 /**
  79  * Map a 2D slice of a texture image into user space.
  80  * (x,y,w,h) defines a region of interest (ROI).  Reading/writing texels
  81  * outside of the ROI is undefined.
  82  *
  83  * \param texImage  the texture image
  84  * \param slice  the 3D image slice or array texture slice
  85  * \param x, y, w, h  region of interest
  86  * \param mode  bitmask of GL_MAP_READ_BIT, GL_MAP_WRITE_BIT
  87  * \param mapOut  returns start of mapping of region of interest
  88  * \param rowStrideOut  returns row stride (in bytes)
  89  */
  90 void
  91 _swrast_map_teximage(struct gl_context *ctx,
  92                      struct gl_texture_image *texImage,
  93                      GLuint slice,
  94                      GLuint x, GLuint y, GLuint w, GLuint h,
  95                      GLbitfield mode,
  96                      GLubyte **mapOut,
  97                      GLint *rowStrideOut)
  98 {
  99    GLubyte *map;
 100    GLint stride, texelSize;
 101    GLuint bw, bh;
 102
 103    _mesa_check_map_teximage(texImage, slice, x, y, w, h);
 104
 105    texelSize = _mesa_get_format_bytes(texImage->TexFormat);
 106    stride = _mesa_format_row_stride(texImage->TexFormat, texImage->Width);
 107    _mesa_get_format_block_size(texImage->TexFormat, &bw, &bh);
 108
 109    assert(texImage->Data);
 110
 111    map = texImage->Data;
 112
 113    if (texImage->TexObject->Target == GL_TEXTURE_3D ||
 114        texImage->TexObject->Target == GL_TEXTURE_2D_ARRAY) {
 115       GLuint sliceSize = _mesa_format_image_size(texImage->TexFormat,
 116                                                  texImage->Width,
 117                                                  texImage->Height,
 118                                                  1);
 119       assert(slice < texImage->Depth);
 120       map += slice * sliceSize;
 121    }
 122
 123    /* apply x/y offset to map address */
 124    map += stride * (y / bh) + texelSize * (x / bw);
 125
 126    *mapOut = map;
 127    *rowStrideOut = stride;
 128 }
 129
 130 void
 131 _swrast_unmap_teximage(struct gl_context *ctx,
 132                        struct gl_texture_image *texImage,
 133                        GLuint slice)
 134 {
 135    /* nop */
 136 }