swrast: Add implementation of MapTextureImage/UnmapTextureImage.

Reviewed-by: Brian Paul <[email protected]>

2 files changed, 123 insertions, 0 deletions

diff --git a/src/mesa/swrast/s_texture.c b/src/mesa/swrast/s_texture.c
new file mode 100644
index 00000000000..6cc72c582f7
--- /dev/null
+++ b/src/mesa/swrast/s_texture.c
@@ -0,0 +1,109 @@
+/*
+ * Mesa 3-D graphics library
+ *
+ * Copyright (C) 2011 VMware, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * Functions for mapping/unmapping texture images.
+ */
+
+
+#include "main/context.h"
+#include "main/fbobject.h"
+#include "swrast/swrast.h"
+#include "swrast/s_context.h"
+
+/**
+ * Error checking for debugging only.
+ */
+static void
+_mesa_check_map_teximage(struct gl_texture_image *texImage,
+                         GLuint slice, GLuint x, GLuint y, GLuint w, GLuint h)
+{
+
+   if (texImage->TexObject->Target == GL_TEXTURE_1D)
+      assert(y == 0 && h == 1);
+
+   assert(x < texImage->Width || texImage->Width == 0);
+   assert(y < texImage->Height || texImage->Height == 0);
+   assert(x + w <= texImage->Width);
+   assert(y + h <= texImage->Height);
+}
+
+/**
+ * Map a 2D slice of a texture image into user space.
+ * (x,y,w,h) defines a region of interest (ROI).  Reading/writing texels
+ * outside of the ROI is undefined.
+ *
+ * \param texImage  the texture image
+ * \param slice  the 3D image slice or array texture slice
+ * \param x, y, w, h  region of interest
+ * \param mode  bitmask of GL_MAP_READ_BIT, GL_MAP_WRITE_BIT
+ * \param mapOut  returns start of mapping of region of interest
+ * \param rowStrideOut  returns row stride (in bytes)
+ */
+void
+_swrast_map_teximage(struct gl_context *ctx,
+                     struct gl_texture_image *texImage,
+                     GLuint slice,
+                     GLuint x, GLuint y, GLuint w, GLuint h,
+                     GLbitfield mode,
+                     GLubyte **mapOut,
+                     GLint *rowStrideOut)
+{
+   GLubyte *map;
+   GLint stride, texelSize;
+   GLuint bw, bh;
+
+   _mesa_check_map_teximage(texImage, slice, x, y, w, h);
+
+   texelSize = _mesa_get_format_bytes(texImage->TexFormat);
+   stride = _mesa_format_row_stride(texImage->TexFormat, texImage->Width);
+   _mesa_get_format_block_size(texImage->TexFormat, &bw, &bh);
+
+   assert(texImage->Data);
+
+   map = texImage->Data;
+
+   if (texImage->TexObject->Target == GL_TEXTURE_3D ||
+       texImage->TexObject->Target == GL_TEXTURE_2D_ARRAY) {
+      GLuint sliceSize = _mesa_format_image_size(texImage->TexFormat,
+                                                 texImage->Width,
+                                                 texImage->Height,
+                                                 1);
+      assert(slice < texImage->Depth);
+      map += slice * sliceSize;
+   }
+
+   /* apply x/y offset to map address */
+   map += stride * (y / bh) + texelSize * (x / bw);
+
+   *mapOut = map;
+   *rowStrideOut = stride;
+}
+
+void
+_swrast_unmap_teximage(struct gl_context *ctx,
+                       struct gl_texture_image *texImage,
+                       GLuint slice)
+{
+   /* nop */
+}
diff --git a/src/mesa/swrast/swrast.h b/src/mesa/swrast/swrast.h
index 27b74c32486..c8b99863568 100644
--- a/src/mesa/swrast/swrast.h
+++ b/src/mesa/swrast/swrast.h
@@ -182,6 +182,20 @@ _swrast_render_start( struct gl_context *ctx );
 extern void
 _swrast_render_finish( struct gl_context *ctx );
 
+extern void
+_swrast_map_teximage(struct gl_context *ctx,
+		     struct gl_texture_image *texImage,
+		     GLuint slice,
+		     GLuint x, GLuint y, GLuint w, GLuint h,
+		     GLbitfield mode,
+		     GLubyte **mapOut,
+		     GLint *rowStrideOut);
+
+extern void
+_swrast_unmap_teximage(struct gl_context *ctx,
+		       struct gl_texture_image *texImage,
+		       GLuint slice);
+
 /* Tell the software rasterizer about core state changes.
  */
 extern void