[Mesa-dev] [PATCH V2 07/10] mesa: Implement functions for clear_buffer_object extensions

Pi Tabred servuswiegehtz at yahoo.de
Fri Dec 13 14:17:57 PST 2013


I tried to tackle this issue:
>> There is still the issue regarding the following:
>> According to the spec, it should be possible to clear some part of a
>> buffer, even if a different, non-overlapping part is mapped, this is
>> currently not possible. It was suggested to implement ClearBufferSubData
>> using MapBufferRange. However, this does not work if a part of the
>> buffer is already mapped.
>> I am not sure how to handle this. Maybe that's something that has to be
>> done inside the different drivers?

I used BufferSubData to transfer the data, however according to the spec
BufferSubData is only guaranteed to work if the complete buffer is
unmapped.

 - _mesa_buffer_clear_subdata: default callback for dd function table
 - _mesa_ClearBufferData: API function
 - _mesa_ClearBufferSubData: API function
 - validate_clear_buffer_format: helper function, check if the
internalformat,
   format and type parameter are legal
 - convert_clear_buffer_data: helper function, convert the supplied data
   to the desired internalformat.
---
 src/mesa/main/bufferobj.c | 259
++++++++++++++++++++++++++++++++++++++++++++++
 src/mesa/main/bufferobj.h |   4 +
 2 files changed, 263 insertions(+)

diff --git a/src/mesa/main/bufferobj.c b/src/mesa/main/bufferobj.c
index 1219891..fb09aa9 100644
--- a/src/mesa/main/bufferobj.c
+++ b/src/mesa/main/bufferobj.c
@@ -41,6 +41,9 @@
 #include "fbobject.h"
 #include "mtypes.h"
 #include "texobj.h"
+#include "teximage.h"
+#include "glformats.h"
+#include "texstore.h"
 #include "transformfeedback.h"
 #include "dispatch.h"

@@ -283,6 +286,96 @@ buffer_object_subdata_range_good(struct gl_context
* ctx, GLenum target,


 /**
+ * Test the format and type parameters and set the GL error code for
+ * \c glClearBufferData and \c glClearBufferSubData.
+ *
+ * \param ctx             GL context.
+ * \param internalformat  Format to which the data is to be converted.
+ * \param format          Format of the supplied data.
+ * \param type            Type of the supplied data.
+ * \param caller          Name of calling function for recording errors.
+ * \return   If internalformat, format and type are legal the gl_format
+ *           corresponding to internalformat, otherwise MESA_FORMAT_NONE.
+ *
+ * \sa glClearBufferData and glClearBufferSubData
+ */
+static gl_format
+validate_clear_buffer_format(struct gl_context *ctx,
+                             GLenum internalformat,
+                             GLenum format, GLenum type,
+                             const char* caller)
+{
+   gl_format mesaFormat;
+   GLenum errorFormatType;
+
+   mesaFormat = _mesa_validate_texbuffer_format(ctx, internalformat);
+   if (mesaFormat == MESA_FORMAT_NONE) {
+      _mesa_error(ctx, GL_INVALID_ENUM,
+                  "%s(invalid internalformat)", caller);
+      return MESA_FORMAT_NONE;
+   }
+
+   /* NOTE: not mentioned in ARB_clear_buffer_object but according to
+    * EXT_texture_integer there is no conversion between integer and
+    * non-integer formats
+   */
+   if (_mesa_is_enum_format_signed_int(format) !=
+       _mesa_is_format_integer_color(mesaFormat)) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "%s(integer vs non-integer)", caller);
+      return MESA_FORMAT_NONE;
+   }
+
+   if (!_mesa_is_color_format(format)) {
+      _mesa_error(ctx, GL_INVALID_ENUM,
+                  "%s(format is not a color format)", caller);
+      return MESA_FORMAT_NONE;
+   }
+
+   errorFormatType = _mesa_error_check_format_and_type(ctx, format,
+                                                       type);
+   if (errorFormatType != GL_NO_ERROR) {
+      _mesa_error(ctx, GL_INVALID_ENUM,
+                  "%s(invalid format or type)", caller);
+      return MESA_FORMAT_NONE;
+   }
+
+   return mesaFormat;
+}
+
+
+/**
+ * Convert user-specified clear value to the specified internal format.
+ *
+ * \param ctx             GL context.
+ * \param internalformat  Format to which the data is converted.
+ * \param clearValue      Pointer, store converted data here.
+ * \param format          Format of the supplied data.
+ * \param type            Type of the supplied data.
+ * \param data            Data which is to be converted to internalformat
+ *
+ * \sa glClearBufferData, glClearBufferSubData
+ */
+static void
+convert_clear_buffer_data(struct gl_context *ctx,
+                          gl_format internalformat,
+                          GLubyte *clearValue, GLenum format, GLenum type,
+                          const GLvoid *data)
+{
+   GLenum internalformatBase;
+
+   internalformatBase = _mesa_get_format_base_format(internalformat);
+
+
+   GLboolean success = _mesa_texstore(ctx, 1, internalformatBase,
+                                      internalformat, 0, &clearValue,
+                                      1, 1, 1,
+                                      format, type, data, &ctx->Unpack);
+   assert(success);
+}
+
+
+/**
  * Allocate and initialize a new buffer object.
  *
  * Default callback for the \c dd_function_table::NewBufferObject() hook.
@@ -547,6 +640,72 @@ _mesa_buffer_get_subdata( struct gl_context *ctx,
GLintptrARB offset,


 /**
+ * Clear a subrange of buffer object with supplied data. If the data range
+ * specified by \c size + \c offset extends beyond the end of the buffer
+ * the error INVALID_VALUE is generated, if data is NULL the buffer is
filled
+ * with zeros.
+ *
+ * This is the default callback for \c
dd_function_table::ClearBufferSubData()
+ * Note that all GL error checking will have been done already.
+ *
+ * \param ctx             GL context.
+ * \param offset          Offset of the first byte to be cleared.
+ * \param size            Size, in bytes, of the to be cleared range.
+ * \param clearValue      Source of the data.
+ * \param clearValueSize  Size, in bytes, of the supplied data.
+ * \param bufObj          Object to be cleared.
+ *
+ * \sa glClearBufferSubDataARB, dd_function_table::ClearBufferSubData.
+ */
+static void
+_mesa_buffer_clear_subdata(struct gl_context *ctx,
+                           GLintptr offset, GLsizeiptr size,
+                           const GLvoid *clearValue,
+                           GLsizeiptr clearValueSize,
+                           struct gl_buffer_object *bufObj)
+{
+   GLsizeiptr i;
+   GLubyte *dest;
+
+   if (_mesa_bufferobj_mapped(bufObj)) {
+      GLubyte *data = malloc(size);
+      GLubyte *dataStart = data;
+
+      if (clearValue == NULL) {
+         memset(data, 0, size);
+      }
+      else {
+         for (i = 0; i < size/clearValueSize; ++i) {
+            memcpy(data, clearValue, clearValueSize);
+            data += clearValueSize;
+         }
+      }
+      ctx->Driver.BufferSubData(ctx, offset, size, dataStart, bufObj);
+      return;
+   }
+
+   ASSERT(ctx->Driver.MapBufferRange);
+   dest = ctx->Driver.MapBufferRange(ctx, offset, size,
+                                     GL_MAP_WRITE_BIT |
+                                     GL_MAP_INVALIDATE_RANGE_BIT,
+                                     bufObj);
+
+   /* Clear range to zero if clearValue == NULL */
+   if (clearValue == NULL) {
+      memset(dest, 0, size);
+      ctx->Driver.UnmapBuffer(ctx, bufObj);
+      return;
+   }
+
+   for (i = 0; i < size/clearValueSize; ++i) {
+      memcpy(dest, clearValue, clearValueSize);
+      dest += clearValueSize;
+   }
+   ctx->Driver.UnmapBuffer(ctx, bufObj);
+}
+
+
+/**
  * Default fallback for \c dd_function_table::MapBufferRange().
  * Called via glMapBufferRange().
  */
@@ -852,6 +1011,9 @@ _mesa_init_buffer_object_functions(struct
dd_function_table *driver)
    driver->GetBufferSubData = _mesa_buffer_get_subdata;
    driver->UnmapBuffer = _mesa_buffer_unmap;

+   /* GL_ARB_clear_buffer_object */
+   driver->ClearBufferSubData = _mesa_buffer_clear_subdata;
+
    /* GL_ARB_map_buffer_range */
    driver->MapBufferRange = _mesa_buffer_map_range;
    driver->FlushMappedBufferRange = _mesa_buffer_flush_mapped_range;
@@ -1182,6 +1344,103 @@ _mesa_GetBufferSubData(GLenum target,
GLintptrARB offset,
 }


+void GLAPIENTRY
+_mesa_ClearBufferData(GLenum target, GLenum internalformat, GLenum format,
+                      GLenum type, const GLvoid* data)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   struct gl_buffer_object* bufObj;
+   gl_format mesaFormat;
+   GLubyte clearValue[MAX_PIXEL_BYTES];
+   GLsizeiptr clearValueSize;
+
+   bufObj = get_buffer(ctx, "glClearBufferData", target, GL_INVALID_VALUE);
+   if (!bufObj) {
+      return;
+   }
+
+   if (_mesa_bufferobj_mapped(bufObj)) {
+       _mesa_error(ctx, GL_INVALID_OPERATION,
+                   "glClearBufferData(buffer currently mapped)");
+       return;
+   }
+
+   mesaFormat = validate_clear_buffer_format(ctx, internalformat,
+                                             format, type,
+                                             "glClearBufferData");
+   if (mesaFormat == MESA_FORMAT_NONE) {
+      return;
+   }
+
+
+   clearValueSize = _mesa_get_format_bytes(mesaFormat);
+   if (bufObj->Size % clearValueSize != 0) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glClearBufferData(size is not a multiple of
internalformat size)");
+      return;
+   }
+
+   if (data == NULL) {
+      ctx->Driver.ClearBufferSubData(ctx, 0, bufObj->Size,
+                                     NULL, 0, bufObj);
+      return;
+   }
+
+   convert_clear_buffer_data(ctx, mesaFormat, clearValue,
+                             format, type, data);
+
+   ctx->Driver.ClearBufferSubData(ctx, 0, bufObj->Size,
+                                  clearValue, clearValueSize, bufObj);
+}
+
+
+void GLAPIENTRY
+_mesa_ClearBufferSubData(GLenum target, GLenum internalformat,
+                         GLintptr offset, GLsizeiptr size,
+                         GLenum format, GLenum type,
+                         const GLvoid* data)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   struct gl_buffer_object* bufObj;
+   gl_format mesaFormat;
+   GLubyte clearValue[MAX_PIXEL_BYTES];
+   GLsizeiptr clearValueSize;
+
+   bufObj = buffer_object_subdata_range_good(ctx, target, offset, size,
+                                             true, GL_INVALID_VALUE,
+                                             "glClearBufferSubData");
+   if (!bufObj) {
+      return;
+   }
+
+   mesaFormat = validate_clear_buffer_format(ctx, internalformat,
+                                             format, type,
+                                             "glClearBufferData");
+   if (mesaFormat == MESA_FORMAT_NONE) {
+      return;
+   }
+
+   clearValueSize = _mesa_get_format_bytes(mesaFormat);
+   if (offset % clearValueSize != 0 || size % clearValueSize != 0) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glClearBufferSubData(offset or size is not a
multiple of internalformat size)");
+      return;
+   }
+
+   if (data == NULL) {
+      ctx->Driver.ClearBufferSubData(ctx, offset, size,
+                                     NULL, 0, bufObj);
+      return;
+   }
+
+   convert_clear_buffer_data(ctx, mesaFormat, clearValue,
+                             format, type, data);
+
+   ctx->Driver.ClearBufferSubData(ctx, offset, size,
+                                  clearValue, clearValueSize, bufObj);
+}
+
+
 void * GLAPIENTRY
 _mesa_MapBuffer(GLenum target, GLenum access)
 {
diff --git a/src/mesa/main/bufferobj.h b/src/mesa/main/bufferobj.h
index 0b898a2..b38519f 100644
--- a/src/mesa/main/bufferobj.h
+++ b/src/mesa/main/bufferobj.h
@@ -120,6 +120,10 @@ void GLAPIENTRY
 _mesa_BufferSubData(GLenum target, GLintptrARB offset, GLsizeiptrARB
size, const GLvoid * data);
 void GLAPIENTRY
 _mesa_GetBufferSubData(GLenum target, GLintptrARB offset, GLsizeiptrARB
size, void * data);
+void GLAPIENTRY
+_mesa_ClearBufferData(GLenum target, GLenum internalformat, GLenum
format, GLenum type, const GLvoid * data);
+void GLAPIENTRY
+_mesa_ClearBufferSubData(GLenum target, GLenum internalformat, GLintptr
offset, GLsizeiptr size, GLenum format, GLenum type, const GLvoid * data);
 void * GLAPIENTRY
 _mesa_MapBuffer(GLenum target, GLenum access);
 GLboolean GLAPIENTRY
-- 
1.8.3.1



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