Mesa (master): mesa: Implement glBindImageTextures

[Fredrik Höglund]

Module: Mesa
Branch: master
Commit: 2a255704564c9ed7cd1a081f7cc3828ee698aa2a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=2a255704564c9ed7cd1a081f7cc3828ee698aa2a

Author: Fredrik Höglund <fredrik at kde.org>
Date:   Fri Jan 17 18:37:06 2014 +0100

mesa: Implement glBindImageTextures

Reviewed-by: Brian Paul <brianp at vmware.com>
Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

---

 src/mesa/main/shaderimage.c |  138 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)

diff --git a/src/mesa/main/shaderimage.c b/src/mesa/main/shaderimage.c
index f77f2c6..9e62f42 100644
--- a/src/mesa/main/shaderimage.c
+++ b/src/mesa/main/shaderimage.c
@@ -33,6 +33,7 @@
 #include "context.h"
 #include "texobj.h"
 #include "teximage.h"
+#include "enums.h"
 
 /*
  * Define endian-invariant aliases for some mesa formats that are
@@ -481,6 +482,143 @@ _mesa_BindImageTexture(GLuint unit, GLuint texture, GLint level,
 void GLAPIENTRY
 _mesa_BindImageTextures(GLuint first, GLsizei count, const GLuint *textures)
 {
+   GET_CURRENT_CONTEXT(ctx);
+   int i;
+
+   if (!ctx->Extensions.ARB_shader_image_load_store) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glBindImageTextures()");
+      return;
+   }
+
+   if (first + count > ctx->Const.MaxImageUnits) {
+      /* The ARB_multi_bind spec says:
+       *
+       *    "An INVALID_OPERATION error is generated if <first> + <count>
+       *     is greater than the number of image units supported by
+       *     the implementation."
+       */
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glBindImageTextures(first=%u + count=%d > the value of "
+                  "GL_MAX_IMAGE_UNITS=%u)",
+                  first, count, ctx->Const.MaxImageUnits);
+      return;
+   }
+
+   /* Assume that at least one binding will be changed */
+   FLUSH_VERTICES(ctx, 0);
+   ctx->NewDriverState |= ctx->DriverFlags.NewImageUnits;
+
+   /* Note that the error semantics for multi-bind commands differ from
+    * those of other GL commands.
+    *
+    * The Issues section in the ARB_multi_bind spec says:
+    *
+    *    "(11) Typically, OpenGL specifies that if an error is generated by
+    *          a command, that command has no effect.  This is somewhat
+    *          unfortunate for multi-bind commands, because it would require
+    *          a first pass to scan the entire list of bound objects for
+    *          errors and then a second pass to actually perform the
+    *          bindings.  Should we have different error semantics?
+    *
+    *       RESOLVED:  Yes.  In this specification, when the parameters for
+    *       one of the <count> binding points are invalid, that binding
+    *       point is not updated and an error will be generated.  However,
+    *       other binding points in the same command will be updated if
+    *       their parameters are valid and no other error occurs."
+    */
+
+   _mesa_begin_texture_lookups(ctx);
+
+   for (i = 0; i < count; i++) {
+      struct gl_image_unit *u = &ctx->ImageUnits[first + i];
+      const GLuint texture = textures ? textures[i] : 0;
+
+      if (texture != 0) {
+         struct gl_texture_object *texObj;
+         struct gl_texture_image *image;
+         mesa_format actualFormat;
+
+         if (!u->TexObj || u->TexObj->Name != texture) {
+            texObj = _mesa_lookup_texture_locked(ctx, texture);
+            if (!texObj) {
+               /* The ARB_multi_bind spec says:
+                *
+                *    "An INVALID_OPERATION error is generated if any value
+                *     in <textures> is not zero or the name of an existing
+                *     texture object (per binding)."
+                */
+               _mesa_error(ctx, GL_INVALID_OPERATION,
+                           "glBindImageTextures(textures[%d]=%u "
+                           "is not zero or the name of an existing texture "
+                           "object)", i, texture);
+               continue;
+            }
+         } else {
+            texObj = u->TexObj;
+         }
+
+         image = texObj->Image[0][0];
+
+         if (!image || image->Width == 0 || image->Height == 0 || image->Depth == 0) {
+            /* The ARB_multi_bind spec says:
+             *
+             *    "An INVALID_OPERATION error is generated if the width,
+             *     height, or depth of the level zero texture image of
+             *     any texture in <textures> is zero (per binding)."
+             */
+            _mesa_error(ctx, GL_INVALID_OPERATION,
+                        "glBindImageTextures(the width, height or depth "
+                        "of the level zero texture image of "
+                        "textures[%d]=%u is zero)", i, texture);
+            continue;
+         }
+
+         actualFormat = get_image_format(image->InternalFormat);
+
+         if (actualFormat == MESA_FORMAT_NONE) {
+            /* The ARB_multi_bind spec says:
+             *
+             *   "An INVALID_OPERATION error is generated if the internal
+             *    format of the level zero texture image of any texture
+             *    in <textures> is not found in table 8.33 (per binding)."
+             */
+            _mesa_error(ctx, GL_INVALID_OPERATION,
+                        "glBindImageTextures(the internal format %s of "
+                        "the level zero texture image of textures[%d]=%u "
+                        "is not supported)",
+                        _mesa_lookup_enum_by_nr(image->InternalFormat),
+                        i, texture);
+            continue;
+         }
+
+         /* Update the texture binding */
+         _mesa_reference_texobj(&u->TexObj, texObj);
+         u->Level = 0;
+         u->Layered = _mesa_tex_target_is_layered(texObj->Target);
+         u->Layer = 0;
+         u->Access = GL_READ_WRITE;
+         u->Format = image->InternalFormat;
+         u->_ActualFormat = actualFormat;
+         u->_Valid = validate_image_unit(ctx, u);
+      } else {
+         /* Unbind the texture from the unit */
+         _mesa_reference_texobj(&u->TexObj, NULL);
+         u->Level = 0;
+         u->Layered = GL_FALSE;
+         u->Layer = 0;
+         u->Access = GL_READ_ONLY;
+         u->Format = GL_R8;
+         u->_ActualFormat = MESA_FORMAT_R_UNORM8;
+         u->_Valid = GL_FALSE;
+      }
+
+      /* Pass the BindImageTexture call down to the device driver */
+      if (ctx->Driver.BindImageTexture)
+         ctx->Driver.BindImageTexture(ctx, u, u->TexObj, u->Level, u->Layered,
+                                      u->Layer, u->Access, u->Format);
+   }
+
+   _mesa_end_texture_lookups(ctx);
 }
 
 void GLAPIENTRY