summaryrefslogtreecommitdiffstats
path: root/src/mesa/swrast/s_texrender.c
blob: 7b25a7b7d81b1d4edd6bf0794f15c98de9c6ae93 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148

#include "main/context.h"
#include "main/colormac.h"
#include "main/fbobject.h"
#include "main/macros.h"
#include "main/teximage.h"
#include "main/renderbuffer.h"
#include "swrast/swrast.h"
#include "swrast/s_context.h"
#include "swrast/s_texfetch.h"


/*
 * Render-to-texture code for GL_EXT_framebuffer_object
 */


static void
delete_texture_wrapper(struct gl_context *ctx, struct gl_renderbuffer *rb)
{
   ASSERT(rb->RefCount == 0);
   free(rb);
}


/**
 * This function creates a renderbuffer object which wraps a texture image.
 * The new renderbuffer is plugged into the given attachment point.
 * This allows rendering into the texture as if it were a renderbuffer.
 */
static void
wrap_texture(struct gl_context *ctx, struct gl_renderbuffer_attachment *att)
{
   struct gl_renderbuffer *rb;
   const GLuint name = 0;

   ASSERT(att->Type == GL_TEXTURE);
   ASSERT(att->Renderbuffer == NULL);

   rb = ctx->Driver.NewRenderbuffer(ctx, name);
   if (!rb) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "wrap_texture");
      return;
   }

   /* init base gl_renderbuffer fields */
   _mesa_init_renderbuffer(rb, name);
   /* plug in our texture_renderbuffer-specific functions */
   rb->Delete = delete_texture_wrapper;
   rb->AllocStorage = NULL; /* illegal! */

   /* update attachment point */
   _mesa_reference_renderbuffer(&att->Renderbuffer, rb);
}

/**
 * Update the renderbuffer wrapper for rendering to a texture.
 * For example, update the width, height of the RB based on the texture size,
 * update the internal format info, etc.
 */
static void
update_wrapper(struct gl_context *ctx, struct gl_renderbuffer_attachment *att)
{
   struct gl_renderbuffer *rb = att->Renderbuffer;
   struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
   struct swrast_texture_image *swImage;
   gl_format format;
   GLuint zOffset;

   (void) ctx;

   swImage = swrast_texture_image(_mesa_get_attachment_teximage(att));
   assert(swImage);

   format = swImage->Base.TexFormat;

   if (att->Texture->Target == GL_TEXTURE_1D_ARRAY_EXT) {
      zOffset = 0;
   }
   else {
      zOffset = att->Zoffset;
   }

   rb->Width = swImage->Base.Width;
   rb->Height = swImage->Base.Height;
   rb->InternalFormat = swImage->Base.InternalFormat;
   rb->_BaseFormat = _mesa_get_format_base_format(format);

   /* Want to store linear values, not sRGB */
   rb->Format = _mesa_get_srgb_format_linear(format);
 
   /* Set the gl_renderbuffer::Buffer field so that mapping the buffer
    * succeeds.
     */
   if (att->Texture->Target == GL_TEXTURE_3D ||
       att->Texture->Target == GL_TEXTURE_2D_ARRAY_EXT) {
      srb->Buffer = swImage->Buffer +
         swImage->ImageOffsets[zOffset] * _mesa_get_format_bytes(format);
   }
   else {
      srb->Buffer = swImage->Buffer;
   }
}



/**
 * Called when rendering to a texture image begins, or when changing
 * the dest mipmap level, cube face, etc.
 * This is a fallback routine for software render-to-texture.
 *
 * Called via the glRenderbufferTexture1D/2D/3D() functions
 * and elsewhere (such as glTexImage2D).
 *
 * The image we're rendering into is
 * att->Texture->Image[att->CubeMapFace][att->TextureLevel];
 * It'll never be NULL.
 *
 * \param fb  the framebuffer object the texture is being bound to
 * \param att  the fb attachment point of the texture
 *
 * \sa _mesa_framebuffer_renderbuffer
 */
void
_swrast_render_texture(struct gl_context *ctx,
                       struct gl_framebuffer *fb,
                       struct gl_renderbuffer_attachment *att)
{
   (void) fb;

   if (!att->Renderbuffer) {
      wrap_texture(ctx, att);
   }
   update_wrapper(ctx, att);
}


void
_swrast_finish_render_texture(struct gl_context *ctx,
                              struct gl_renderbuffer_attachment *att)
{
   /* do nothing */
   /* The renderbuffer texture wrapper will get deleted by the
    * normal mechanism for deleting renderbuffers.
    */
   (void) ctx;
   (void) att;
}