/**
* Update internal counters based on the the drawing operation described in
* prim.
*/
static void
brw_update_primitive_count(struct brw_context *brw,
const struct _mesa_prim *prim)
{
uint32_t count
= vbo_count_tessellated_primitives(prim->mode, prim->count,
prim->num_instances);
brw->sol.primitives_generated += count;
if (_mesa_is_xfb_active_and_unpaused(&brw->intel.ctx)) {
/* Update brw->sol.svbi_0_max_index to reflect the amount by which the
* hardware is going to increment SVBI 0 when this drawing operation
* occurs. This is necessary because the kernel does not (yet) save and
* restore GPU registers when context switching, so we'll need to be
* able to reload SVBI 0 with the correct value in case we have to start
* a new batch buffer.
*/
unsigned verts = verts_per_prim(prim->mode);
uint32_t space_avail =
(brw->sol.svbi_0_max_index - brw->sol.svbi_0_starting_index) / verts;
uint32_t primitives_written = MIN2 (space_avail, count);
brw->sol.svbi_0_starting_index += verts * primitives_written;
/* And update the TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN query. */
brw->sol.primitives_written += primitives_written;
}
}
/**
* Called from the tnl module to error check the function parameters and
* verify that we really can draw something.
* \return GL_TRUE if OK to render, GL_FALSE if error found
*/
GLboolean
_mesa_validate_DrawArrays(struct gl_context *ctx,
GLenum mode, GLint start, GLsizei count)
{
struct gl_transform_feedback_object *xfb_obj
= ctx->TransformFeedback.CurrentObject;
FLUSH_CURRENT(ctx, 0);
if (count <= 0) {
if (count < 0)
_mesa_error(ctx, GL_INVALID_VALUE, "glDrawArrays(count)" );
return GL_FALSE;
}
if (!_mesa_valid_prim_mode(ctx, mode, "glDrawArrays")) {
return GL_FALSE;
}
if (!check_valid_to_render(ctx, "glDrawArrays"))
return GL_FALSE;
if (ctx->Const.CheckArrayBounds) {
if (start + count > (GLint) ctx->Array.ArrayObj->_MaxElement)
return GL_FALSE;
}
/* From the GLES3 specification, section 2.14.2 (Transform Feedback
* Primitive Capture):
*
* The error INVALID_OPERATION is generated by DrawArrays and
* DrawArraysInstanced if recording the vertices of a primitive to the
* buffer objects being used for transform feedback purposes would result
* in either exceeding the limits of any buffer object’s size, or in
* exceeding the end position offset + size − 1, as set by
* BindBufferRange.
*
* This is in contrast to the behaviour of desktop GL, where the extra
* primitives are silently dropped from the transform feedback buffer.
*/
if (_mesa_is_gles3(ctx) && _mesa_is_xfb_active_and_unpaused(ctx)) {
size_t prim_count = vbo_count_tessellated_primitives(mode, count, 1);
if (xfb_obj->GlesRemainingPrims < prim_count) {
_mesa_error(ctx, GL_INVALID_OPERATION,
"glDrawArrays(exceeds transform feedback size)");
return GL_FALSE;
}
xfb_obj->GlesRemainingPrims -= prim_count;
}
return GL_TRUE;
}
static bool
validate_draw_arrays(struct gl_context *ctx, const char *func,
GLenum mode, GLsizei count, GLsizei numInstances)
{
struct gl_transform_feedback_object *xfb_obj
= ctx->TransformFeedback.CurrentObject;
FLUSH_CURRENT(ctx, 0);
if (count < 0) {
_mesa_error(ctx, GL_INVALID_VALUE, "%s(count)", func);
return false;
}
if (!_mesa_valid_prim_mode(ctx, mode, func))
return false;
if (!check_valid_to_render(ctx, func))
return false;
/* From the GLES3 specification, section 2.14.2 (Transform Feedback
* Primitive Capture):
*
* The error INVALID_OPERATION is generated by DrawArrays and
* DrawArraysInstanced if recording the vertices of a primitive to the
* buffer objects being used for transform feedback purposes would result
* in either exceeding the limits of any buffer object’s size, or in
* exceeding the end position offset + size − 1, as set by
* BindBufferRange.
*
* This is in contrast to the behaviour of desktop GL, where the extra
* primitives are silently dropped from the transform feedback buffer.
*
* This text is removed in ES 3.2, presumably because it's not really
* implementable with geometry and tessellation shaders. In fact,
* the OES_geometry_shader spec says:
*
* "(13) Does this extension change how transform feedback operates
* compared to unextended OpenGL ES 3.0 or 3.1?
*
* RESOLVED: Yes. Because dynamic geometry amplification in a geometry
* shader can make it difficult if not impossible to predict the amount
* of geometry that may be generated in advance of executing the shader,
* the draw-time error for transform feedback buffer overflow conditions
* is removed and replaced with the GL behavior (primitives are not
* written and the corresponding counter is not updated)..."
*/
if (_mesa_is_gles3(ctx) && _mesa_is_xfb_active_and_unpaused(ctx) &&
!_mesa_has_OES_geometry_shader(ctx) &&
!_mesa_has_OES_tessellation_shader(ctx)) {
size_t prim_count = vbo_count_tessellated_primitives(mode, count, 1);
if (xfb_obj->GlesRemainingPrims < prim_count) {
_mesa_error(ctx, GL_INVALID_OPERATION,
"%s(exceeds transform feedback size)", func);
return false;
}
xfb_obj->GlesRemainingPrims -= prim_count;
}
if (count == 0)
return false;
return true;
}
