[Mesa-dev] [PATCH 1/2] mesa: Fix glGetTransformFeedbackVarying().
Eric Anholt
eric at anholt.net
Tue Jan 3 18:52:37 PST 2012
The current implementation was totally broken -- it was looking in an
unpopulated structure for varyings, and trying to do so using the
current list of varying names, not the list used at link time.
---
src/glsl/linker.cpp | 37 +++++++++++++++++++++++++++++++------
src/mesa/main/mtypes.h | 21 ++++++++++++++++++++-
src/mesa/main/transformfeedback.c | 37 +++++++++++--------------------------
3 files changed, 62 insertions(+), 33 deletions(-)
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 6587008..bf72a55 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -1382,7 +1382,8 @@ public:
bool assign_location(struct gl_context *ctx, struct gl_shader_program *prog,
ir_variable *output_var);
bool store(struct gl_shader_program *prog,
- struct gl_transform_feedback_info *info, unsigned buffer) const;
+ struct gl_transform_feedback_info *info, unsigned buffer,
+ unsigned varying) const;
/**
@@ -1413,7 +1414,7 @@ public:
private:
/**
* The name that was supplied to glTransformFeedbackVaryings. Used for
- * error reporting.
+ * error reporting and glGetTransformFeedbackVarying().
*/
const char *orig_name;
@@ -1449,6 +1450,9 @@ private:
* if this variable is not a matrix.
*/
unsigned matrix_columns;
+
+ /** Type of the varying returned by glGetTransformFeedbackVarying() */
+ GLenum type;
};
@@ -1520,8 +1524,9 @@ tfeedback_decl::assign_location(struct gl_context *ctx,
/* Array variable */
if (!this->is_array) {
linker_error(prog, "Transform feedback varying %s found, "
- "but it's not an array ([] not expected).",
- this->orig_name);
+ "but array dereference required for varying %s[%d]).",
+ this->orig_name,
+ output_var->name, output_var->type->length);
return false;
}
/* Check array bounds. */
@@ -1538,6 +1543,7 @@ tfeedback_decl::assign_location(struct gl_context *ctx,
this->location = output_var->location + this->array_index * matrix_cols;
this->vector_elements = output_var->type->fields.array->vector_elements;
this->matrix_columns = matrix_cols;
+ this->type = GL_NONE;
} else {
/* Regular variable (scalar, vector, or matrix) */
if (this->is_array) {
@@ -1549,6 +1555,7 @@ tfeedback_decl::assign_location(struct gl_context *ctx,
this->location = output_var->location;
this->vector_elements = output_var->type->vector_elements;
this->matrix_columns = output_var->type->matrix_columns;
+ this->type = output_var->type->gl_type;
}
/* From GL_EXT_transform_feedback:
* A program will fail to link if:
@@ -1580,7 +1587,7 @@ tfeedback_decl::assign_location(struct gl_context *ctx,
bool
tfeedback_decl::store(struct gl_shader_program *prog,
struct gl_transform_feedback_info *info,
- unsigned buffer) const
+ unsigned buffer, unsigned varying) const
{
if (!this->is_assigned()) {
/* From GL_EXT_transform_feedback:
@@ -1602,6 +1609,16 @@ tfeedback_decl::store(struct gl_shader_program *prog,
++info->NumOutputs;
info->BufferStride[buffer] += this->vector_elements;
}
+
+ info->Varyings[varying].Name = ralloc_strdup(prog, this->orig_name);
+ info->Varyings[varying].Type = this->type;
+ /* Since we require that transform feedback varyings dereference
+ * arrays, there's always only one element of the GL datatype above
+ * present in this varying.
+ */
+ info->Varyings[varying].Size = 1;
+ info->NumVarying++;
+
return true;
}
@@ -1865,13 +1882,21 @@ store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog,
tfeedback_decl *tfeedback_decls)
{
unsigned total_tfeedback_components = 0;
+
+ ralloc_free(prog->LinkedTransformFeedback.Varyings);
+
memset(&prog->LinkedTransformFeedback, 0,
sizeof(prog->LinkedTransformFeedback));
+
+ prog->LinkedTransformFeedback.Varyings =
+ rzalloc_array(prog, struct gl_transform_feedback_varying_info,
+ num_tfeedback_decls);
+
for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
unsigned buffer =
prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS ? i : 0;
if (!tfeedback_decls[i].store(prog, &prog->LinkedTransformFeedback,
- buffer))
+ buffer, i))
return false;
total_tfeedback_components += tfeedback_decls[i].num_components();
}
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 107371e..9f0ef69 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -1817,6 +1817,12 @@ struct prog_instruction;
struct gl_program_parameter_list;
struct gl_uniform_list;
+struct gl_transform_feedback_varying_info {
+ char *Name;
+ GLenum Type;
+ GLint Size;
+};
+
/** Post-link transform feedback info. */
struct gl_transform_feedback_info {
unsigned NumOutputs;
@@ -1830,6 +1836,13 @@ struct gl_transform_feedback_info {
unsigned DstOffset;
} Outputs[MAX_PROGRAM_OUTPUTS];
+ /** Transform feedback varyings used for the linking of this shader program.
+ *
+ * Use for glGetTransformFeedbackVarying().
+ */
+ struct gl_transform_feedback_varying_info *Varyings;
+ GLint NumVarying;
+
/**
* Total number of components stored in each buffer. This may be used by
* hardware back-ends to determine the correct stride when interleaving
@@ -2222,7 +2235,13 @@ struct gl_shader_program
*/
struct string_to_uint_map *FragDataBindings;
- /** Transform feedback varyings */
+ /**
+ * Transform feedback varyings last specified by
+ * glTransformFeedbackVaryings().
+ *
+ * For the current set of transform feeedback varyings used for transform
+ * feedback output, see LinkedTransformFeedback.
+ */
struct {
GLenum BufferMode;
GLuint NumVarying;
diff --git a/src/mesa/main/transformfeedback.c b/src/mesa/main/transformfeedback.c
index be0d0ff..16ac5dd 100644
--- a/src/mesa/main/transformfeedback.c
+++ b/src/mesa/main/transformfeedback.c
@@ -662,8 +662,7 @@ _mesa_GetTransformFeedbackVarying(GLuint program, GLuint index,
GLsizei *size, GLenum *type, GLchar *name)
{
const struct gl_shader_program *shProg;
- const GLchar *varyingName;
- GLint v;
+ const struct gl_transform_feedback_info *linked_xfb_info;
GET_CURRENT_CONTEXT(ctx);
shProg = _mesa_lookup_shader_program(ctx, program);
@@ -673,36 +672,22 @@ _mesa_GetTransformFeedbackVarying(GLuint program, GLuint index,
return;
}
- if (index >= shProg->TransformFeedback.NumVarying) {
+ linked_xfb_info = &shProg->LinkedTransformFeedback;
+ if (index >= linked_xfb_info->NumVarying) {
_mesa_error(ctx, GL_INVALID_VALUE,
"glGetTransformFeedbackVaryings(index=%u)", index);
return;
}
- varyingName = shProg->TransformFeedback.VaryingNames[index];
+ /* return the varying's name and length */
+ _mesa_copy_string(name, bufSize, length,
+ linked_xfb_info->Varyings[index].Name);
- v = _mesa_lookup_parameter_index(shProg->Varying, -1, varyingName);
- if (v >= 0) {
- struct gl_program_parameter *param = &shProg->Varying->Parameters[v];
-
- /* return the varying's name and length */
- _mesa_copy_string(name, bufSize, length, varyingName);
-
- /* return the datatype and value's size (in datatype units) */
- if (type)
- *type = param->DataType;
- if (size)
- *size = param->Size;
- }
- else {
- name[0] = 0;
- if (length)
- *length = 0;
- if (type)
- *type = 0;
- if (size)
- *size = 0;
- }
+ /* return the datatype and value's size (in datatype units) */
+ if (type)
+ *type = linked_xfb_info->Varyings[index].Type;
+ if (size)
+ *size = linked_xfb_info->Varyings[index].Size;
}
--
1.7.7.3
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