aboutsummaryrefslogtreecommitdiff
path: root/mesalib/src/mesa/main/transformfeedback.c
diff options
context:
space:
mode:
Diffstat (limited to 'mesalib/src/mesa/main/transformfeedback.c')
-rw-r--r--mesalib/src/mesa/main/transformfeedback.c135
1 files changed, 113 insertions, 22 deletions
diff --git a/mesalib/src/mesa/main/transformfeedback.c b/mesalib/src/mesa/main/transformfeedback.c
index 22060c34c..1bf4beaeb 100644
--- a/mesalib/src/mesa/main/transformfeedback.c
+++ b/mesalib/src/mesa/main/transformfeedback.c
@@ -34,6 +34,7 @@
#include "bufferobj.h"
#include "context.h"
#include "hash.h"
+#include "macros.h"
#include "mfeatures.h"
#include "mtypes.h"
#include "transformfeedback.h"
@@ -79,6 +80,7 @@ reference_transform_feedback_object(struct gl_transform_feedback_object **ptr,
}
else {
obj->RefCount++;
+ obj->EverBound = GL_TRUE;
*ptr = obj;
}
}
@@ -177,6 +179,7 @@ new_transform_feedback(struct gl_context *ctx, GLuint name)
if (obj) {
obj->Name = name;
obj->RefCount = 1;
+ obj->EverBound = GL_FALSE;
}
return obj;
}
@@ -246,6 +249,83 @@ _mesa_init_transform_feedback_functions(struct dd_function_table *driver)
/**
+ * Fill in the correct Size value for each buffer in \c obj.
+ *
+ * From the GL 4.3 spec, section 6.1.1 ("Binding Buffer Objects to Indexed
+ * Targets"):
+ *
+ * BindBufferBase binds the entire buffer, even when the size of the buffer
+ * is changed after the binding is established. It is equivalent to calling
+ * BindBufferRange with offset zero, while size is determined by the size of
+ * the bound buffer at the time the binding is used.
+ *
+ * Regardless of the size specified with BindBufferRange, or indirectly with
+ * BindBufferBase, the GL will never read or write beyond the end of a bound
+ * buffer. In some cases this constraint may result in visibly different
+ * behavior when a buffer overflow would otherwise result, such as described
+ * for transform feedback operations in section 13.2.2.
+ */
+static void
+compute_transform_feedback_buffer_sizes(
+ struct gl_transform_feedback_object *obj)
+{
+ unsigned i = 0;
+ for (i = 0; i < MAX_FEEDBACK_BUFFERS; ++i) {
+ GLintptr offset = obj->Offset[i];
+ GLsizeiptr buffer_size
+ = obj->Buffers[i] == NULL ? 0 : obj->Buffers[i]->Size;
+ GLsizeiptr available_space
+ = buffer_size <= offset ? 0 : buffer_size - offset;
+ GLsizeiptr computed_size;
+ if (obj->RequestedSize[i] == 0) {
+ /* No size was specified at the time the buffer was bound, so allow
+ * writing to all available space in the buffer.
+ */
+ computed_size = available_space;
+ } else {
+ /* A size was specified at the time the buffer was bound, however
+ * it's possible that the buffer has shrunk since then. So only
+ * allow writing to the minimum of the specified size and the space
+ * available.
+ */
+ computed_size = MIN2(available_space, obj->RequestedSize[i]);
+ }
+
+ /* Legal sizes must be multiples of four, so round down if necessary. */
+ obj->Size[i] = computed_size & ~0x3;
+ }
+}
+
+
+/**
+ * Compute the maximum number of vertices that can be written to the currently
+ * enabled transform feedback buffers without overflowing any of them.
+ */
+unsigned
+_mesa_compute_max_transform_feedback_vertices(
+ const struct gl_transform_feedback_object *obj,
+ const struct gl_transform_feedback_info *info)
+{
+ unsigned max_index = 0xffffffff;
+ unsigned i;
+
+ for (i = 0; i < info->NumBuffers; ++i) {
+ unsigned stride = info->BufferStride[i];
+ unsigned max_for_this_buffer;
+
+ /* Skip any inactive buffers, which have a stride of 0. */
+ if (stride == 0)
+ continue;
+
+ max_for_this_buffer = obj->Size[i] / (4 * stride);
+ max_index = MIN2(max_index, max_for_this_buffer);
+ }
+
+ return max_index;
+}
+
+
+/**
** Begin API functions
**/
@@ -256,6 +336,7 @@ _mesa_BeginTransformFeedback(GLenum mode)
struct gl_transform_feedback_object *obj;
struct gl_transform_feedback_info *info;
GLuint i;
+ unsigned vertices_per_prim;
GET_CURRENT_CONTEXT(ctx);
obj = ctx->TransformFeedback.CurrentObject;
@@ -276,9 +357,13 @@ _mesa_BeginTransformFeedback(GLenum mode)
switch (mode) {
case GL_POINTS:
+ vertices_per_prim = 1;
+ break;
case GL_LINES:
+ vertices_per_prim = 2;
+ break;
case GL_TRIANGLES:
- /* legal */
+ vertices_per_prim = 3;
break;
default:
_mesa_error(ctx, GL_INVALID_ENUM, "glBeginTransformFeedback(mode)");
@@ -304,6 +389,20 @@ _mesa_BeginTransformFeedback(GLenum mode)
obj->Active = GL_TRUE;
ctx->TransformFeedback.Mode = mode;
+ compute_transform_feedback_buffer_sizes(obj);
+
+ if (_mesa_is_gles3(ctx)) {
+ /* In GLES3, we are required to track the usage of the transform
+ * feedback buffer and report INVALID_OPERATION if a draw call tries to
+ * exceed it. So compute the maximum number of vertices that we can
+ * write without overflowing any of the buffers currently being used for
+ * feedback.
+ */
+ unsigned max_vertices
+ = _mesa_compute_max_transform_feedback_vertices(obj, info);
+ obj->GlesRemainingPrims = max_vertices / vertices_per_prim;
+ }
+
assert(ctx->Driver.BeginTransformFeedback);
ctx->Driver.BeginTransformFeedback(ctx, mode, obj);
}
@@ -362,7 +461,7 @@ bind_buffer_range(struct gl_context *ctx, GLuint index,
obj->BufferNames[index] = bufObj->Name;
obj->Offset[index] = offset;
- obj->Size[index] = size;
+ obj->RequestedSize[index] = size;
}
@@ -421,7 +520,6 @@ _mesa_bind_buffer_base_transform_feedback(struct gl_context *ctx,
struct gl_buffer_object *bufObj)
{
struct gl_transform_feedback_object *obj;
- GLsizeiptr size;
obj = ctx->TransformFeedback.CurrentObject;
@@ -436,12 +534,7 @@ _mesa_bind_buffer_base_transform_feedback(struct gl_context *ctx,
return;
}
- /* default size is the buffer size rounded down to nearest
- * multiple of four.
- */
- size = bufObj->Size & ~0x3;
-
- bind_buffer_range(ctx, index, bufObj, 0, size);
+ bind_buffer_range(ctx, index, bufObj, 0, 0);
}
@@ -457,7 +550,6 @@ _mesa_BindBufferOffsetEXT(GLenum target, GLuint index, GLuint buffer,
struct gl_transform_feedback_object *obj;
struct gl_buffer_object *bufObj;
GET_CURRENT_CONTEXT(ctx);
- GLsizeiptr size;
if (target != GL_TRANSFORM_FEEDBACK_BUFFER) {
_mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferOffsetEXT(target)");
@@ -497,12 +589,7 @@ _mesa_BindBufferOffsetEXT(GLenum target, GLuint index, GLuint buffer,
return;
}
- /* default size is the buffer size rounded down to nearest
- * multiple of four.
- */
- size = (bufObj->Size - offset) & ~0x3;
-
- bind_buffer_range(ctx, index, bufObj, offset, size);
+ bind_buffer_range(ctx, index, bufObj, offset, 0);
}
@@ -708,14 +795,19 @@ _mesa_GenTransformFeedbacks(GLsizei n, GLuint *names)
GLboolean GLAPIENTRY
_mesa_IsTransformFeedback(GLuint name)
{
+ struct gl_transform_feedback_object *obj;
GET_CURRENT_CONTEXT(ctx);
ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
- if (name && _mesa_lookup_transform_feedback_object(ctx, name))
- return GL_TRUE;
- else
+ if (name == 0)
return GL_FALSE;
+
+ obj = _mesa_lookup_transform_feedback_object(ctx, name);
+ if (obj == NULL)
+ return GL_FALSE;
+
+ return obj->EverBound;
}
@@ -734,8 +826,7 @@ _mesa_BindTransformFeedback(GLenum target, GLuint name)
return;
}
- if (ctx->TransformFeedback.CurrentObject->Active &&
- !ctx->TransformFeedback.CurrentObject->Paused) {
+ if (_mesa_is_xfb_active_and_unpaused(ctx)) {
_mesa_error(ctx, GL_INVALID_OPERATION,
"glBindTransformFeedback(transform is active, or not paused)");
return;
@@ -805,7 +896,7 @@ _mesa_PauseTransformFeedback(void)
obj = ctx->TransformFeedback.CurrentObject;
- if (!obj->Active || obj->Paused) {
+ if (!_mesa_is_xfb_active_and_unpaused(ctx)) {
_mesa_error(ctx, GL_INVALID_OPERATION,
"glPauseTransformFeedback(feedback not active or already paused)");
return;