mesa: Fill out ARB_texture_view entry points

Add Mesa TextureView logic.
Incorporate feedback on ARB_texture_view:
- Add S3TC VIEW_CLASSes to compatibility table
- Use existing _mesa_get_tex_image
- Clean up error strings
- Use bool instead of GLboolean for internal functions
- Split compound level & layer test into individual tests
- eliminate helper macro for VIEW_CLASS table
- do not call driver if ptr null.

Signed-off-by: Courtney Goeltzenleuchter <courtney@LunarG.com>

Reviewed-by: Brian Paul <brianp@vmware.com>

1 files changed, 538 insertions, 1 deletions

diff --git a/src/mesa/main/textureview.c b/src/mesa/main/textureview.c
index 4a6bd62..1094993 100644
--- a/src/mesa/main/textureview.c
+++ b/src/mesa/main/textureview.c
@@ -38,10 +38,315 @@
 #include "macros.h"
 #include "teximage.h"
 #include "texobj.h"
+#include "mipmap.h"
 #include "texstorage.h"
 #include "textureview.h"
+#include "stdbool.h"
 #include "mtypes.h"
 
+/* Table 3.X.2 (Compatible internal formats for TextureView)
+    ---------------------------------------------------------------------------
+    | Class                 | Internal formats                                |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_128_BITS   | RGBA32F, RGBA32UI, RGBA32I                      |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_96_BITS    | RGB32F, RGB32UI, RGB32I                         |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_64_BITS    | RGBA16F, RG32F, RGBA16UI, RG32UI, RGBA16I,      |
+    |                       | RG32I, RGBA16, RGBA16_SNORM                     |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_48_BITS    | RGB16, RGB16_SNORM, RGB16F, RGB16UI, RGB16I     |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_32_BITS    | RG16F, R11F_G11F_B10F, R32F,                    |
+    |                       | RGB10_A2UI, RGBA8UI, RG16UI, R32UI,             |
+    |                       | RGBA8I, RG16I, R32I, RGB10_A2, RGBA8, RG16,     |
+    |                       | RGBA8_SNORM, RG16_SNORM, SRGB8_ALPHA8, RGB9_E5  |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_24_BITS    | RGB8, RGB8_SNORM, SRGB8, RGB8UI, RGB8I          |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_16_BITS    | R16F, RG8UI, R16UI, RG8I, R16I, RG8, R16,       |
+    |                       | RG8_SNORM, R16_SNORM                            |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_8_BITS     | R8UI, R8I, R8, R8_SNORM                         |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_RGTC1_RED  | COMPRESSED_RED_RGTC1,                           |
+    |                       | COMPRESSED_SIGNED_RED_RGTC1                     |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_RGTC2_RG   | COMPRESSED_RG_RGTC2,                            |
+    |                       | COMPRESSED_SIGNED_RG_RGTC2                      |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_BPTC_UNORM | COMPRESSED_RGBA_BPTC_UNORM,                     |
+    |                       | COMPRESSED_SRGB_ALPHA_BPTC_UNORM                |
+    ---------------------------------------------------------------------------
+    | VIEW_CLASS_BPTC_FLOAT | COMPRESSED_RGB_BPTC_SIGNED_FLOAT,               |
+    |                       | COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT              |
+    ---------------------------------------------------------------------------
+ */
+struct internal_format_class_info {
+   GLenum view_class;
+   GLenum internal_format;
+};
+static const struct internal_format_class_info compatible_internal_formats[] = {
+   {GL_VIEW_CLASS_128_BITS, GL_RGBA32F},
+   {GL_VIEW_CLASS_128_BITS, GL_RGBA32UI},
+   {GL_VIEW_CLASS_128_BITS, GL_RGBA32I},
+   {GL_VIEW_CLASS_96_BITS, GL_RGB32F},
+   {GL_VIEW_CLASS_96_BITS, GL_RGB32UI},
+   {GL_VIEW_CLASS_96_BITS, GL_RGB32I},
+   {GL_VIEW_CLASS_64_BITS, GL_RGBA16F},
+   {GL_VIEW_CLASS_64_BITS, GL_RG32F},
+   {GL_VIEW_CLASS_64_BITS, GL_RGBA16UI},
+   {GL_VIEW_CLASS_64_BITS, GL_RG32UI},
+   {GL_VIEW_CLASS_64_BITS, GL_RGBA16I},
+   {GL_VIEW_CLASS_64_BITS, GL_RG32I},
+   {GL_VIEW_CLASS_64_BITS, GL_RGBA16},
+   {GL_VIEW_CLASS_64_BITS, GL_RGBA16_SNORM},
+   {GL_VIEW_CLASS_48_BITS, GL_RGB16},
+   {GL_VIEW_CLASS_48_BITS, GL_RGB16_SNORM},
+   {GL_VIEW_CLASS_48_BITS, GL_RGB16F},
+   {GL_VIEW_CLASS_48_BITS, GL_RGB16UI},
+   {GL_VIEW_CLASS_48_BITS, GL_RGB16I},
+   {GL_VIEW_CLASS_32_BITS, GL_RG16F},
+   {GL_VIEW_CLASS_32_BITS, GL_R11F_G11F_B10F},
+   {GL_VIEW_CLASS_32_BITS, GL_R32F},
+   {GL_VIEW_CLASS_32_BITS, GL_RGB10_A2UI},
+   {GL_VIEW_CLASS_32_BITS, GL_RGBA8UI},
+   {GL_VIEW_CLASS_32_BITS, GL_RG16UI},
+   {GL_VIEW_CLASS_32_BITS, GL_R32UI},
+   {GL_VIEW_CLASS_32_BITS, GL_RGBA8I},
+   {GL_VIEW_CLASS_32_BITS, GL_RG16I},
+   {GL_VIEW_CLASS_32_BITS, GL_R32I},
+   {GL_VIEW_CLASS_32_BITS, GL_RGB10_A2},
+   {GL_VIEW_CLASS_32_BITS, GL_RGBA8},
+   {GL_VIEW_CLASS_32_BITS, GL_RG16},
+   {GL_VIEW_CLASS_32_BITS, GL_RGBA8_SNORM},
+   {GL_VIEW_CLASS_32_BITS, GL_RG16_SNORM},
+   {GL_VIEW_CLASS_32_BITS, GL_SRGB8_ALPHA8},
+   {GL_VIEW_CLASS_32_BITS, GL_RGB9_E5},
+   {GL_VIEW_CLASS_24_BITS, GL_RGB8},
+   {GL_VIEW_CLASS_24_BITS, GL_RGB8_SNORM},
+   {GL_VIEW_CLASS_24_BITS, GL_SRGB8},
+   {GL_VIEW_CLASS_24_BITS, GL_RGB8UI},
+   {GL_VIEW_CLASS_24_BITS, GL_RGB8I},
+   {GL_VIEW_CLASS_16_BITS, GL_R16F},
+   {GL_VIEW_CLASS_16_BITS, GL_RG8UI},
+   {GL_VIEW_CLASS_16_BITS, GL_R16UI},
+   {GL_VIEW_CLASS_16_BITS, GL_RG8I},
+   {GL_VIEW_CLASS_16_BITS, GL_R16I},
+   {GL_VIEW_CLASS_16_BITS, GL_RG8},
+   {GL_VIEW_CLASS_16_BITS, GL_R16},
+   {GL_VIEW_CLASS_16_BITS, GL_RG8_SNORM},
+   {GL_VIEW_CLASS_16_BITS, GL_R16_SNORM},
+   {GL_VIEW_CLASS_8_BITS, GL_R8UI},
+   {GL_VIEW_CLASS_8_BITS, GL_R8I},
+   {GL_VIEW_CLASS_8_BITS, GL_R8},
+   {GL_VIEW_CLASS_8_BITS, GL_R8_SNORM},
+   {GL_VIEW_CLASS_RGTC1_RED, GL_COMPRESSED_RED_RGTC1},
+   {GL_VIEW_CLASS_RGTC1_RED, GL_COMPRESSED_SIGNED_RED_RGTC1},
+   {GL_VIEW_CLASS_RGTC2_RG, GL_COMPRESSED_RG_RGTC2},
+   {GL_VIEW_CLASS_RGTC2_RG, GL_COMPRESSED_SIGNED_RG_RGTC2},
+   {GL_VIEW_CLASS_BPTC_UNORM, GL_COMPRESSED_RGBA_BPTC_UNORM_ARB},
+   {GL_VIEW_CLASS_BPTC_UNORM, GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB},
+   {GL_VIEW_CLASS_BPTC_FLOAT, GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_ARB},
+   {GL_VIEW_CLASS_BPTC_FLOAT, GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_ARB},
+};
+
+static const struct internal_format_class_info s3tc_compatible_internal_formats[] = {
+   {GL_VIEW_CLASS_S3TC_DXT1_RGB, GL_COMPRESSED_RGB_S3TC_DXT1_EXT},
+   {GL_VIEW_CLASS_S3TC_DXT1_RGB, GL_COMPRESSED_SRGB_S3TC_DXT1_EXT},
+   {GL_VIEW_CLASS_S3TC_DXT1_RGBA, GL_COMPRESSED_RGBA_S3TC_DXT1_EXT},
+   {GL_VIEW_CLASS_S3TC_DXT1_RGBA, GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT},
+   {GL_VIEW_CLASS_S3TC_DXT3_RGBA, GL_COMPRESSED_RGBA_S3TC_DXT3_EXT},
+   {GL_VIEW_CLASS_S3TC_DXT3_RGBA, GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT},
+   {GL_VIEW_CLASS_S3TC_DXT5_RGBA, GL_COMPRESSED_RGBA_S3TC_DXT5_EXT},
+   {GL_VIEW_CLASS_S3TC_DXT5_RGBA, GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT},
+};
+
+/**
+ * Lookup format view class based on internalformat
+ * \return VIEW_CLASS if internalformat found in table, false otherwise.
+ */
+static GLenum
+lookup_view_class(struct gl_context *ctx, GLenum internalformat)
+{
+   uint i;
+
+   for (i = 0; i < ARRAY_SIZE(compatible_internal_formats); i++) {
+      if (compatible_internal_formats[i].internal_format == internalformat)
+         return compatible_internal_formats[i].view_class;
+   }
+
+   if (ctx->Extensions.EXT_texture_compression_s3tc && ctx->Extensions.EXT_texture_sRGB) {
+      for (i = 0; i < ARRAY_SIZE(s3tc_compatible_internal_formats); i++) {
+         if (s3tc_compatible_internal_formats[i].internal_format == internalformat)
+            return s3tc_compatible_internal_formats[i].view_class;
+      }
+   }
+   return GL_FALSE;
+}
+
+/**
+ * Initialize new texture's gl_texture_image structures. Will not call driver
+ * to allocate new space, simply record relevant layer, face, format, etc.
+ * \return GL_FALSE if any error, GL_TRUE otherwise.
+ */
+static GLboolean
+initialize_texture_fields(struct gl_context *ctx,
+                          GLenum target,
+                          struct gl_texture_object *texObj,
+                          GLint levels,
+                          GLsizei width, GLsizei height, GLsizei depth,
+                          GLenum internalFormat, gl_format texFormat)
+{
+   const GLuint numFaces = _mesa_num_tex_faces(target);
+   GLint level, levelWidth = width, levelHeight = height, levelDepth = depth;
+   GLuint face;
+
+   /* Pretend we are bound to initialize the gl_texture_image structs */
+   texObj->Target = target;
+
+   /* Set up all the texture object's gl_texture_images */
+   for (level = 0; level < levels; level++) {
+      for (face = 0; face < numFaces; face++) {
+         struct gl_texture_image *texImage =
+                 _mesa_get_tex_image(ctx, texObj, face, level);
+
+         if (!texImage) {
+            _mesa_error(ctx, GL_OUT_OF_MEMORY, "glTexStorage");
+            return GL_FALSE;
+         }
+
+         _mesa_init_teximage_fields(ctx, texImage,
+                                    levelWidth, levelHeight, levelDepth,
+                                    0, internalFormat, texFormat);
+      }
+
+      _mesa_next_mipmap_level_size(target, 0, levelWidth, levelHeight, levelDepth,
+                                   &levelWidth, &levelHeight, &levelDepth);
+   }
+
+   /* "unbind" */
+   texObj->Target = 0;
+
+   return GL_TRUE;
+}
+
+#define RETURN_IF_SUPPORTED(t) do {		\
+   if (newTarget == GL_ ## t)                   \
+      return true;				\
+} while (0)
+
+/**
+ * Check for compatible target
+ * If an error is found, record it with _mesa_error()
+ * \return false if any error, true otherwise.
+ */
+static bool
+target_valid(struct gl_context *ctx, GLenum origTarget, GLenum newTarget)
+{
+   /*
+    * From ARB_texture_view spec:
+   ---------------------------------------------------------------------------------------------------------
+   | Original target              | Valid new targets |
+   ---------------------------------------------------------------------------------------------------------
+   | TEXTURE_1D                   | TEXTURE_1D, TEXTURE_1D_ARRAY |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_2D                   | TEXTURE_2D, TEXTURE_2D_ARRAY |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_3D                   | TEXTURE_3D |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_CUBE_MAP             | TEXTURE_CUBE_MAP, TEXTURE_2D, TEXTURE_2D_ARRAY, TEXTURE_CUBE_MAP_ARRAY |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_RECTANGLE            | TEXTURE_RECTANGLE |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_BUFFER               | <none> |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_1D_ARRAY             | TEXTURE_1D_ARRAY, TEXTURE_1D |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_2D_ARRAY             | TEXTURE_2D_ARRAY, TEXTURE_2D, TEXTURE_CUBE_MAP, TEXTURE_CUBE_MAP_ARRAY |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_CUBE_MAP_ARRAY       | TEXTURE_CUBE_MAP_ARRAY, TEXTURE_2D_ARRAY, TEXTURE_2D, TEXTURE_CUBE_MAP |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_2D_MULTISAMPLE       | TEXTURE_2D_MULTISAMPLE, TEXTURE_2D_MULTISAMPLE_ARRAY |
+   | ------------------------------------------------------------------------------------------------------- |
+   | TEXTURE_2D_MULTISAMPLE_ARRAY | TEXTURE_2D_MULTISAMPLE, TEXTURE_2D_MULTISAMPLE_ARRAY |
+   ---------------------------------------------------------------------------------------------------------
+    */
+
+   switch (origTarget) {
+   case GL_TEXTURE_1D:
+   case GL_TEXTURE_1D_ARRAY:
+      RETURN_IF_SUPPORTED(TEXTURE_1D);
+      RETURN_IF_SUPPORTED(TEXTURE_1D_ARRAY);
+      break;
+   case GL_TEXTURE_2D:
+      RETURN_IF_SUPPORTED(TEXTURE_2D);
+      RETURN_IF_SUPPORTED(TEXTURE_2D_ARRAY);
+      break;
+   case GL_TEXTURE_3D:
+      RETURN_IF_SUPPORTED(TEXTURE_3D);
+      break;
+   case GL_TEXTURE_RECTANGLE:
+      RETURN_IF_SUPPORTED(TEXTURE_RECTANGLE);
+      break;
+   case GL_TEXTURE_CUBE_MAP:
+   case GL_TEXTURE_2D_ARRAY:
+   case GL_TEXTURE_CUBE_MAP_ARRAY:
+      RETURN_IF_SUPPORTED(TEXTURE_2D);
+      RETURN_IF_SUPPORTED(TEXTURE_2D_ARRAY);
+      RETURN_IF_SUPPORTED(TEXTURE_CUBE_MAP);
+      RETURN_IF_SUPPORTED(TEXTURE_CUBE_MAP_ARRAY);
+      break;
+   case GL_TEXTURE_2D_MULTISAMPLE:
+   case GL_TEXTURE_2D_MULTISAMPLE_ARRAY:
+      RETURN_IF_SUPPORTED(TEXTURE_2D_MULTISAMPLE);
+      RETURN_IF_SUPPORTED(TEXTURE_2D_MULTISAMPLE_ARRAY);
+      break;
+   }
+   _mesa_error(ctx, GL_INVALID_OPERATION,
+               "glTextureView(illegal target=%s)",
+               _mesa_lookup_enum_by_nr(newTarget));
+   return false;
+}
+#undef RETURN_IF_SUPPORTED
+
+/**
+ * Check for compatible format
+ * If an error is found, record it with _mesa_error()
+ * \return false if any error, true otherwise.
+ */
+static bool
+compatible_format(struct gl_context *ctx, const struct gl_texture_object *origTexObj,
+                  GLenum internalformat)
+{
+   /* Level 0 of a texture created by glTextureStorage or glTextureView
+    * is always defined.
+    */
+   struct gl_texture_image *texImage = origTexObj->Image[0][0];
+   GLint origInternalFormat = texImage->InternalFormat;
+   unsigned int origViewClass, newViewClass;
+
+   /* The two textures' internal formats must be compatible according to
+    * Table 3.X.2 (Compatible internal formats for TextureView)
+    * if the internal format exists in that table the view class must match.
+    * The internal formats must be identical if not in that table,
+    * or an INVALID_OPERATION error is generated.
+    */
+   if (origInternalFormat == internalformat)
+      return true;
+
+   origViewClass = lookup_view_class(ctx, origInternalFormat);
+   newViewClass = lookup_view_class(ctx, internalformat);
+   if ((origViewClass == newViewClass) && origViewClass != false)
+      return true;
+
+   _mesa_error(ctx, GL_INVALID_OPERATION,
+               "glTextureView(internalformat %s not compatible with origtexture %s)",
+               _mesa_lookup_enum_by_nr(internalformat),
+               _mesa_lookup_enum_by_nr(origInternalFormat));
+   return false;
+}
+
 /**
  * glTextureView (ARB_texture_view)
  * If an error is found, record it with _mesa_error()
@@ -53,13 +358,245 @@ _mesa_TextureView(GLuint texture, GLenum target, GLuint origtexture,
                   GLuint minlevel, GLuint numlevels,
                   GLuint minlayer, GLuint numlayers)
 {
+   struct gl_texture_object *texObj;
+   struct gl_texture_object *origTexObj;
+   struct gl_texture_image *origTexImage;
+   GLuint newViewMinLevel, newViewMinLayer;
+   GLuint newViewNumLevels, newViewNumLayers;
+   GLsizei width, height, depth;
+   gl_format texFormat;
+   GLboolean sizeOK, dimensionsOK;
+   GLenum faceTarget;
+
    GET_CURRENT_CONTEXT(ctx);
 
    if (MESA_VERBOSE & (VERBOSE_API | VERBOSE_TEXTURE))
-      _mesa_debug(ctx, "glTextureView (unfinished) %d %s %d %s %d %d %d %d\n",
+      _mesa_debug(ctx, "glTextureView %d %s %d %s %d %d %d %d\n",
                   texture, _mesa_lookup_enum_by_nr(target), origtexture,
                   _mesa_lookup_enum_by_nr(internalformat),
                   minlevel, numlevels, minlayer, numlayers);
 
+   if (origtexture == 0) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(origtexture = %u)", origtexture);
+      return;
+   }
+
+   /* Need original texture information to validate arguments */
+   origTexObj = _mesa_lookup_texture(ctx, origtexture);
+
+   /* If <origtexture> is not the name of a texture, INVALID_VALUE is generated. */
+   if (!origTexObj) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(origtexture = %u)", origtexture);
+      return;
+   }
+
+   /* If <origtexture>'s TEXTURE_IMMUTABLE_FORMAT value is not TRUE,
+    * INVALID_OPERATION is generated.
+    */
+   if (!origTexObj->Immutable) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(origtexture not immutable)");
+      return;
+   }
+
+   /* If <texture> is 0, INVALID_VALUE is generated. */
+   if (texture == 0) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(texture = 0)");
+      return;
+   }
+
+   /* If <texture> is not a valid name returned by GenTextures,
+    * the error INVALID_OPERATION is generated.
+    */
+   texObj = _mesa_lookup_texture(ctx, texture);
+   if (texObj == NULL) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(texture = %u non-gen name)", texture);
+      return;
+   }
+
+   /* If <texture> has already been bound and given a target, then
+    * the error INVALID_OPERATION is generated.
+    */
+   if (texObj->Target) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(texture = %u already bound)", texture);
+      return;
+   }
+
+   /* Check for compatible target */
+   if (!target_valid(ctx, origTexObj->Target, target)) {
+      return; /* error was recorded */
+   }
+
+   /* minlevel and minlayer are relative to the view of origtexture
+    * If minlevel or minlayer is greater than level or layer, respectively,
+    * of origtexture return INVALID_VALUE.
+    */
+   newViewMinLevel = origTexObj->MinLevel + minlevel;
+   newViewMinLayer = origTexObj->MinLayer + minlayer;
+   if (newViewMinLevel >= (origTexObj->MinLevel + origTexObj->NumLevels)) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glTextureView(new minlevel (%d) > orig minlevel (%d) + orig numlevels (%d))",
+                  newViewMinLevel, origTexObj->MinLevel, origTexObj->NumLevels);
+      return;
+   }
+
+   if (newViewMinLayer >= (origTexObj->MinLayer + origTexObj->NumLayers)) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glTextureView(new minlayer (%d) > orig minlayer (%d) + orig numlayers (%d))",
+                  newViewMinLayer, origTexObj->MinLayer, origTexObj->NumLayers);
+      return;
+   }
+
+   if (!compatible_format(ctx, origTexObj, internalformat)) {
+      return; /* Error logged */
+   }
+
+   texFormat = _mesa_choose_texture_format(ctx, texObj, target, 0,
+                                           internalformat, GL_NONE, GL_NONE);
+   assert(texFormat != MESA_FORMAT_NONE);
+   if (texFormat == MESA_FORMAT_NONE) return;
+
+   newViewNumLevels = MIN2(numlevels, origTexObj->NumLevels - minlevel);
+   newViewNumLayers = MIN2(numlayers, origTexObj->NumLayers - minlayer);
+
+   faceTarget = origTexObj->Target;
+   if (faceTarget == GL_TEXTURE_CUBE_MAP)
+      faceTarget = GL_TEXTURE_CUBE_MAP_POSITIVE_X + minlayer;
+
+   /* Get a reference to what will become this View's base level */
+   origTexImage = _mesa_select_tex_image(ctx, origTexObj,
+                                         faceTarget, minlevel);
+   width = origTexImage->Width;
+   height = origTexImage->Height;
+   depth = origTexImage->Depth;
+
+   /* Adjust width, height, depth to be appropriate for new target */
+   switch (target) {
+   case GL_TEXTURE_1D:
+   case GL_TEXTURE_3D:
+      break;
+
+   case GL_TEXTURE_1D_ARRAY:
+      height = (GLsizei) newViewNumLayers;
+      break;
+
+   case GL_TEXTURE_2D:
+   case GL_TEXTURE_2D_MULTISAMPLE:
+   case GL_TEXTURE_RECTANGLE:
+   case GL_TEXTURE_CUBE_MAP:
+      depth = 1;
+      break;
+
+   case GL_TEXTURE_2D_ARRAY:
+   case GL_TEXTURE_CUBE_MAP_ARRAY:
+   case GL_TEXTURE_2D_MULTISAMPLE_ARRAY:
+      depth = newViewNumLayers;
+      break;
+   }
+
+   /* If the dimensions of the original texture are larger than the maximum
+    * supported dimensions of the new target, the error INVALID_OPERATION is
+    * generated. For example, if the original texture has a TEXTURE_2D_ARRAY
+    * target and its width is greater than MAX_CUBE_MAP_TEXTURE_SIZE, an error
+    * will be generated if TextureView is called to create a TEXTURE_CUBE_MAP
+    * view.
+    */
+   dimensionsOK = _mesa_legal_texture_dimensions(ctx, target, 0,
+                                                 width, height, depth, 0);
+   if (!dimensionsOK) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(invalid width or height or depth)");
+      return;
+   }
+
+   sizeOK = ctx->Driver.TestProxyTexImage(ctx, target, 0, texFormat,
+                                          width, height, depth, 0);
+   if (!sizeOK) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(invalid texture size)");
+      return;
+   }
+
+   /* If <target> is TEXTURE_1D, TEXTURE_2D, TEXTURE_3D, TEXTURE_RECTANGLE,
+    * or TEXTURE_2D_MULTISAMPLE and <numlayers> does not equal 1, the error
+    * INVALID_VALUE is generated.
+    */
+   switch (target) {
+   case GL_TEXTURE_1D:
+   case GL_TEXTURE_2D:
+   case GL_TEXTURE_3D:
+   case GL_TEXTURE_RECTANGLE:
+   case GL_TEXTURE_2D_MULTISAMPLE:
+      if (numlayers != 1) {
+         _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(numlayers %d != 1)", numlayers);
+         return;
+      }
+      break;
+
+   case GL_TEXTURE_CUBE_MAP:
+      /* If the new texture's target is TEXTURE_CUBE_MAP, the clamped <numlayers>
+       * must be equal to 6.
+       */
+      if (newViewNumLayers != 6) {
+         _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(clamped numlayers %d != 6)",
+                     newViewNumLayers);
+         return;
+      }
+      break;
+
+   case GL_TEXTURE_CUBE_MAP_ARRAY:
+      /* If the new texture's target is TEXTURE_CUBE_MAP_ARRAY,
+       * then <numlayers> counts layer-faces rather than layers,
+       * and the clamped <numlayers> must be a multiple of 6.
+       * Otherwise, the error INVALID_VALUE is generated.
+       */
+      if ((newViewNumLayers % 6) != 0) {
+         _mesa_error(ctx, GL_INVALID_VALUE,
+                     "glTextureView(clamped numlayers %d is not a multiple of 6)",
+                     newViewNumLayers);
+         return;
+      }
+      break;
+   }
+
+   /* If the new texture's target is TEXTURE_CUBE_MAP or
+    * TEXTURE_CUBE_MAP_ARRAY, the width and height of the original texture's
+    * levels must be equal otherwise the error INVALID_OPERATION is generated.
+    */
+   if ((target == GL_TEXTURE_CUBE_MAP || target == GL_TEXTURE_CUBE_MAP_ARRAY) &&
+       (origTexImage->Width != origTexImage->Height)) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(origtexture width (%d) != height (%d))",
+                  origTexImage->Width, origTexImage->Height);
+      return;
+   }
+
+   /* When the original texture's target is TEXTURE_CUBE_MAP, the layer
+    * parameters are interpreted in the same order as if it were a
+    * TEXTURE_CUBE_MAP_ARRAY with 6 layer-faces.
+    */
+
+   /* If the internal format does not exactly match the internal format of the
+    * original texture, the contents of the memory are reinterpreted in the
+    * same manner as for image bindings described in
+    * section 3.9.20 (Texture Image Loads and Stores).
+    */
+
+   /* TEXTURE_BASE_LEVEL and TEXTURE_MAX_LEVEL are interpreted
+    * relative to the view and not relative to the original data store.
+    */
+
+   if (!initialize_texture_fields(ctx, target, texObj, newViewNumLevels,
+                                  width, height, depth,
+                                  internalformat, texFormat)) {
+      return; /* Already recorded error */
+   }
+
+   texObj->MinLevel = newViewMinLevel;
+   texObj->MinLayer = newViewMinLayer;
+   texObj->NumLevels = newViewNumLevels;
+   texObj->NumLayers = newViewNumLayers;
+   texObj->Immutable = GL_TRUE;
+   texObj->ImmutableLevels = origTexObj->ImmutableLevels;
+   texObj->Target = target;
 
+   if (ctx->Driver.TextureView != NULL && !ctx->Driver.TextureView(ctx, texObj, origTexObj)) {
+      return; /* driver recorded error */
+   }
 }