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
18static void
19delete_texture_wrapper(struct gl_context *ctx, struct gl_renderbuffer *rb)
20{
21   ASSERT(rb->RefCount == 0);
22   free(rb);
23}
24
25
26/**
27 * This function creates a renderbuffer object which wraps a texture image.
28 * The new renderbuffer is plugged into the given attachment point.
29 * This allows rendering into the texture as if it were a renderbuffer.
30 */
31static void
32wrap_texture(struct gl_context *ctx, struct gl_renderbuffer_attachment *att)
33{
34   struct gl_renderbuffer *rb;
35   const GLuint name = 0;
36
37   ASSERT(att->Type == GL_TEXTURE);
38   ASSERT(att->Renderbuffer == NULL);
39
40   rb = ctx->Driver.NewRenderbuffer(ctx, name);
41   if (!rb) {
42      _mesa_error(ctx, GL_OUT_OF_MEMORY, "wrap_texture");
43      return;
44   }
45
46   /* init base gl_renderbuffer fields */
47   _mesa_init_renderbuffer(rb, name);
48   /* plug in our texture_renderbuffer-specific functions */
49   rb->Delete = delete_texture_wrapper;
50   rb->AllocStorage = NULL; /* illegal! */
51
52   /* update attachment point */
53   _mesa_reference_renderbuffer(&att->Renderbuffer, rb);
54}
55
56/**
57 * Update the renderbuffer wrapper for rendering to a texture.
58 * For example, update the width, height of the RB based on the texture size,
59 * update the internal format info, etc.
60 */
61static void
62update_wrapper(struct gl_context *ctx, struct gl_renderbuffer_attachment *att)
63{
64   struct gl_renderbuffer *rb = att->Renderbuffer;
65   struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
66   struct swrast_texture_image *swImage;
67   gl_format format;
68   GLuint zOffset;
69
70   (void) ctx;
71
72   swImage = swrast_texture_image(_mesa_get_attachment_teximage(att));
73   assert(swImage);
74
75   format = swImage->Base.TexFormat;
76
77   if (att->Texture->Target == GL_TEXTURE_1D_ARRAY_EXT) {
78      zOffset = 0;
79   }
80   else {
81      zOffset = att->Zoffset;
82   }
83
84   rb->Width = swImage->Base.Width;
85   rb->Height = swImage->Base.Height;
86   rb->InternalFormat = swImage->Base.InternalFormat;
87   rb->_BaseFormat = _mesa_get_format_base_format(format);
88
89   /* Want to store linear values, not sRGB */
90   rb->Format = _mesa_get_srgb_format_linear(format);
91
92   /* Set the gl_renderbuffer::Buffer field so that mapping the buffer
93    * succeeds.
94     */
95   if (att->Texture->Target == GL_TEXTURE_3D ||
96       att->Texture->Target == GL_TEXTURE_2D_ARRAY_EXT) {
97      srb->Buffer = swImage->Buffer +
98         swImage->ImageOffsets[zOffset] * _mesa_get_format_bytes(format);
99   }
100   else {
101      srb->Buffer = swImage->Buffer;
102   }
103}
104
105
106
107/**
108 * Called when rendering to a texture image begins, or when changing
109 * the dest mipmap level, cube face, etc.
110 * This is a fallback routine for software render-to-texture.
111 *
112 * Called via the glRenderbufferTexture1D/2D/3D() functions
113 * and elsewhere (such as glTexImage2D).
114 *
115 * The image we're rendering into is
116 * att->Texture->Image[att->CubeMapFace][att->TextureLevel];
117 * It'll never be NULL.
118 *
119 * \param fb  the framebuffer object the texture is being bound to
120 * \param att  the fb attachment point of the texture
121 *
122 * \sa _mesa_framebuffer_renderbuffer
123 */
124void
125_swrast_render_texture(struct gl_context *ctx,
126                       struct gl_framebuffer *fb,
127                       struct gl_renderbuffer_attachment *att)
128{
129   (void) fb;
130
131   if (!att->Renderbuffer) {
132      wrap_texture(ctx, att);
133   }
134   update_wrapper(ctx, att);
135}
136
137
138void
139_swrast_finish_render_texture(struct gl_context *ctx,
140                              struct gl_renderbuffer_attachment *att)
141{
142   /* do nothing */
143   /* The renderbuffer texture wrapper will get deleted by the
144    * normal mechanism for deleting renderbuffers.
145    */
146   (void) ctx;
147   (void) att;
148}
149