src/mesa/swrast/s_texrender.c

   1
   2 #include "main/context.h"
   3 #include "main/colormac.h"
   4 #include "main/fbobject.h"
   5 #include "main/macros.h"
   6 #include "main/teximage.h"
   7 #include "main/renderbuffer.h"
   8 #include "swrast/swrast.h"
   9 #include "swrast/s_context.h"
  10 #include "swrast/s_texfetch.h"
  11
  12
  13 /*
  14  * Render-to-texture code for GL_EXT_framebuffer_object
  15  */
  16
  17
  18 /**
  19  * Derived from gl_renderbuffer class
  20  */
  21 struct texture_renderbuffer
  22 {
  23    struct gl_renderbuffer Base;   /**< Base class object */
  24    struct swrast_texture_image *TexImage;
  25    StoreTexelFunc Store;
  26    FetchTexelFunc Fetch;
  27    GLint Yoffset;                 /**< Layer for 1D array textures. */
  28    GLint Zoffset;                 /**< Layer for 2D array textures, or slice
  29                                    * for 3D textures
  30                                    */
  31 };
  32
  33
  34 /** cast wrapper */
  35 static inline struct texture_renderbuffer *
  36 texture_renderbuffer(struct gl_renderbuffer *rb)
  37 {
  38    return (struct texture_renderbuffer *) rb;
  39 }
  40
  41
  42
  43
  44 static void
  45 store_nop(struct swrast_texture_image *texImage,
  46           GLint col, GLint row, GLint img,
  47           const void *texel)
  48 {
  49 }
  50
  51
  52 static void
  53 delete_texture_wrapper(struct gl_renderbuffer *rb)
  54 {
  55    ASSERT(rb->RefCount == 0);
  56    free(rb);
  57 }
  58
  59
  60 /**
  61  * This function creates a renderbuffer object which wraps a texture image.
  62  * The new renderbuffer is plugged into the given attachment point.
  63  * This allows rendering into the texture as if it were a renderbuffer.
  64  */
  65 static void
  66 wrap_texture(struct gl_context *ctx, struct gl_renderbuffer_attachment *att)
  67 {
  68    struct texture_renderbuffer *trb;
  69    const GLuint name = 0;
  70
  71    ASSERT(att->Type == GL_TEXTURE);
  72    ASSERT(att->Renderbuffer == NULL);
  73
  74    trb = CALLOC_STRUCT(texture_renderbuffer);
  75    if (!trb) {
  76       _mesa_error(ctx, GL_OUT_OF_MEMORY, "wrap_texture");
  77       return;
  78    }
  79
  80    /* init base gl_renderbuffer fields */
  81    _mesa_init_renderbuffer(&trb->Base, name);
  82    /* plug in our texture_renderbuffer-specific functions */
  83    trb->Base.Delete = delete_texture_wrapper;
  84    trb->Base.AllocStorage = NULL; /* illegal! */
  85
  86    /* update attachment point */
  87    _mesa_reference_renderbuffer(&att->Renderbuffer, &(trb->Base));
  88 }
  89
  90 /**
  91  * Update the renderbuffer wrapper for rendering to a texture.
  92  * For example, update the width, height of the RB based on the texture size,
  93  * update the internal format info, etc.
  94  */
  95 static void
  96 update_wrapper(struct gl_context *ctx, struct gl_renderbuffer_attachment *att)
  97 {
  98    struct texture_renderbuffer *trb
  99       = (struct texture_renderbuffer *) att->Renderbuffer;
 100
 101    (void) ctx;
 102    ASSERT(trb);
 103
 104    trb->TexImage = swrast_texture_image(_mesa_get_attachment_teximage(att));
 105    ASSERT(trb->TexImage);
 106
 107    trb->Store = _mesa_get_texel_store_func(trb->TexImage->Base.TexFormat);
 108    if (!trb->Store) {
 109       /* we'll never draw into some textures (compressed formats) */
 110       trb->Store = store_nop;
 111    }
 112
 113    if (!trb->TexImage->FetchTexel) {
 114       _mesa_update_fetch_functions(trb->TexImage->Base.TexObject);
 115    }
 116    trb->Fetch = trb->TexImage->FetchTexel;
 117    assert(trb->Fetch);
 118
 119    if (att->Texture->Target == GL_TEXTURE_1D_ARRAY_EXT) {
 120       trb->Yoffset = att->Zoffset;
 121       trb->Zoffset = 0;
 122    }
 123    else {
 124       trb->Yoffset = 0;
 125       trb->Zoffset = att->Zoffset;
 126    }
 127
 128    trb->Base.Width = trb->TexImage->Base.Width;
 129    trb->Base.Height = trb->TexImage->Base.Height;
 130    trb->Base.RowStride = trb->TexImage->RowStride;
 131    trb->Base.InternalFormat = trb->TexImage->Base.InternalFormat;
 132    trb->Base.Format = trb->TexImage->Base.TexFormat;
 133
 134    /* Set the gl_renderbuffer::Data field so that mapping the buffer
 135     * in renderbuffer.c succeeds.
 136     */
 137    if (att->Texture->Target == GL_TEXTURE_3D ||
 138        att->Texture->Target == GL_TEXTURE_2D_ARRAY_EXT) {
 139       trb->Base.Data = trb->TexImage->Buffer +
 140          trb->TexImage->ImageOffsets[trb->Zoffset] *
 141          _mesa_get_format_bytes(trb->TexImage->Base.TexFormat);
 142    }
 143    else {
 144       trb->Base.Data = trb->TexImage->Buffer;
 145    }
 146
 147    /* XXX may need more special cases here */
 148    switch (trb->TexImage->Base.TexFormat) {
 149    case MESA_FORMAT_Z24_S8:
 150       trb->Base.DataType = GL_UNSIGNED_INT_24_8_EXT;
 151       trb->Base._BaseFormat = GL_DEPTH_STENCIL;
 152       break;
 153    case MESA_FORMAT_S8_Z24:
 154       trb->Base.DataType = GL_UNSIGNED_INT_8_24_REV_MESA;
 155       trb->Base._BaseFormat = GL_DEPTH_STENCIL;
 156       break;
 157    case MESA_FORMAT_Z24_X8:
 158       trb->Base.DataType = GL_UNSIGNED_INT_24_8_EXT;
 159       trb->Base._BaseFormat = GL_DEPTH_COMPONENT;
 160       break;
 161    case MESA_FORMAT_X8_Z24:
 162       trb->Base.DataType = GL_UNSIGNED_INT_8_24_REV_MESA;
 163       trb->Base._BaseFormat = GL_DEPTH_COMPONENT;
 164       break;
 165    case MESA_FORMAT_Z16:
 166       trb->Base.DataType = GL_UNSIGNED_SHORT;
 167       trb->Base._BaseFormat = GL_DEPTH_COMPONENT;
 168       break;
 169    case MESA_FORMAT_Z32:
 170       trb->Base.DataType = GL_UNSIGNED_INT;
 171       trb->Base._BaseFormat = GL_DEPTH_COMPONENT;
 172       break;
 173    /* SRGB formats pre EXT_framebuffer_sRGB don't do sRGB translations on FBO readback */
 174    case MESA_FORMAT_SRGB8:
 175       trb->Fetch = _mesa_get_texel_fetch_func(MESA_FORMAT_RGB888, _mesa_get_texture_dimensions(att->Texture->Target));
 176       trb->Base.DataType = CHAN_TYPE;
 177       trb->Base._BaseFormat = GL_RGBA;
 178       break;
 179    case MESA_FORMAT_SRGBA8:
 180       trb->Fetch = _mesa_get_texel_fetch_func(MESA_FORMAT_RGBA8888, _mesa_get_texture_dimensions(att->Texture->Target));
 181       trb->Base.DataType = CHAN_TYPE;
 182       trb->Base._BaseFormat = GL_RGBA;
 183       break;
 184    case MESA_FORMAT_SARGB8:
 185       trb->Fetch = _mesa_get_texel_fetch_func(MESA_FORMAT_ARGB8888, _mesa_get_texture_dimensions(att->Texture->Target));
 186       trb->Base.DataType = CHAN_TYPE;
 187       trb->Base._BaseFormat = GL_RGBA;
 188       break;
 189    default:
 190       trb->Base.DataType = CHAN_TYPE;
 191       trb->Base._BaseFormat = GL_RGBA;
 192    }
 193 }
 194
 195
 196
 197 /**
 198  * Called when rendering to a texture image begins, or when changing
 199  * the dest mipmap level, cube face, etc.
 200  * This is a fallback routine for software render-to-texture.
 201  *
 202  * Called via the glRenderbufferTexture1D/2D/3D() functions
 203  * and elsewhere (such as glTexImage2D).
 204  *
 205  * The image we're rendering into is
 206  * att->Texture->Image[att->CubeMapFace][att->TextureLevel];
 207  * It'll never be NULL.
 208  *
 209  * \param fb  the framebuffer object the texture is being bound to
 210  * \param att  the fb attachment point of the texture
 211  *
 212  * \sa _mesa_framebuffer_renderbuffer
 213  */
 214 void
 215 _swrast_render_texture(struct gl_context *ctx,
 216                        struct gl_framebuffer *fb,
 217                        struct gl_renderbuffer_attachment *att)
 218 {
 219    (void) fb;
 220
 221    if (!att->Renderbuffer) {
 222       wrap_texture(ctx, att);
 223    }
 224    update_wrapper(ctx, att);
 225 }
 226
 227
 228 void
 229 _swrast_finish_render_texture(struct gl_context *ctx,
 230                               struct gl_renderbuffer_attachment *att)
 231 {
 232    /* do nothing */
 233    /* The renderbuffer texture wrapper will get deleted by the
 234     * normal mechanism for deleting renderbuffers.
 235     */
 236    (void) ctx;
 237    (void) att;
 238 }