From 257420b0f7fdc96162239777db35c640df315975 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 10 May 2016 19:04:03 -0400
Subject: [PATCH] Fixed potential output error if buffer top were hit;
clarified buffer size constants.
---
Outputs/CRT/CRT.cpp | 34 ++++++++++++--------------
Outputs/CRT/CRT.hpp | 9 +++++--
Outputs/CRT/Internals/CRTConstants.hpp | 4 +--
3 files changed, 24 insertions(+), 23 deletions(-)
diff --git a/Outputs/CRT/CRT.cpp b/Outputs/CRT/CRT.cpp
index 712823fc1..74c50d7e4 100644
--- a/Outputs/CRT/CRT.cpp
+++ b/Outputs/CRT/CRT.cpp
@@ -69,8 +69,7 @@ CRT::CRT(unsigned int common_output_divisor) :
_common_output_divisor(common_output_divisor),
_is_writing_composite_run(false),
_delegate(nullptr),
- _frames_since_last_delegate_call(0),
- _did_start_run(false) {}
+ _frames_since_last_delegate_call(0) {}
CRT::CRT(unsigned int cycles_per_line, unsigned int common_output_divisor, unsigned int height_of_display, ColourSpace colour_space, unsigned int colour_cycle_numerator, unsigned int colour_cycle_denominator, unsigned int buffer_depth) : CRT(common_output_divisor)
{
@@ -187,29 +186,26 @@ void CRT::advance_cycles(unsigned int number_of_cycles, unsigned int source_divi
if(needs_endpoint)
{
if(
- _is_writing_composite_run == _did_start_run &&
_openGL_output_builder->composite_output_run_has_room_for_vertex() &&
!_openGL_output_builder->composite_output_buffer_is_full())
{
- uint8_t *next_run = _openGL_output_builder->get_next_output_run();
- if(next_run)
+ if(!_is_writing_composite_run)
{
- if(_did_start_run)
- {
- output_x1() = (uint16_t)_horizontal_flywheel->get_current_output_position();
- output_position_y() = (uint16_t)(_vertical_flywheel->get_current_output_position() / _vertical_flywheel_output_divider);
- output_tex_y() = _openGL_output_builder->get_composite_output_y();
- }
- else
- {
- output_x2() = (uint16_t)_horizontal_flywheel->get_current_output_position();
- _openGL_output_builder->complete_output_run();
- }
-
- _did_start_run ^= true;
+ _output_run.x1 = (uint16_t)_horizontal_flywheel->get_current_output_position();
+ _output_run.y = (uint16_t)(_vertical_flywheel->get_current_output_position() / _vertical_flywheel_output_divider);
+ _output_run.tex_y = _openGL_output_builder->get_composite_output_y();
}
+ else
+ {
+ uint8_t *next_run = _openGL_output_builder->get_next_output_run();
+ output_x1() = _output_run.x1;
+ output_position_y() = _output_run.y;
+ output_tex_y() = _output_run.tex_y;
+ output_x2() = (uint16_t)_horizontal_flywheel->get_current_output_position();
+ _openGL_output_builder->complete_output_run();
+ }
+ _is_writing_composite_run ^= true;
}
- _is_writing_composite_run ^= true;
}
if(next_run_length == time_until_horizontal_sync_event && next_horizontal_sync_event == Flywheel::SyncEvent::StartRetrace)
diff --git a/Outputs/CRT/CRT.hpp b/Outputs/CRT/CRT.hpp
index 3ea5858ab..a38e63795 100644
--- a/Outputs/CRT/CRT.hpp
+++ b/Outputs/CRT/CRT.hpp
@@ -68,7 +68,7 @@ class CRT {
uint8_t _colour_burst_phase, _colour_burst_amplitude;
uint16_t _colour_burst_time;
- bool _is_writing_composite_run, _did_start_run;
+ bool _is_writing_composite_run;
// the outer entry point for dispatching output_sync, output_blank, output_level and output_data
void advance_cycles(unsigned int number_of_cycles, unsigned int source_divider, bool hsync_requested, bool vsync_requested, const bool vsync_charging, const Scan::Type type, uint16_t tex_x, uint16_t tex_y);
@@ -81,7 +81,12 @@ class CRT {
// OpenGL state, kept behind an opaque pointer to avoid inclusion of the GL headers here.
std::unique_ptr<OpenGLOutputBuilder> _openGL_output_builder;
- // The delegate;
+ // temporary storage used during the construction of output runs
+ struct {
+ uint16_t x1, y, tex_y;
+ } _output_run;
+
+ // The delegate
Delegate *_delegate;
unsigned int _frames_since_last_delegate_call;
diff --git a/Outputs/CRT/Internals/CRTConstants.hpp b/Outputs/CRT/Internals/CRTConstants.hpp
index bcf6c5385..e1c8a3207 100644
--- a/Outputs/CRT/Internals/CRTConstants.hpp
+++ b/Outputs/CRT/Internals/CRTConstants.hpp
@@ -40,8 +40,8 @@ const GLsizei IntermediateBufferWidth = 2048;
const GLsizei IntermediateBufferHeight = 1024;
// Some internal buffer sizes
-const GLsizeiptr OutputVertexBufferDataSize = 8 * IntermediateBufferHeight; // likely always to be OutputVertexSize * IntermediateBufferHeight, that being the maximum number of scans of output that can be created between draws
-const GLsizeiptr SourceVertexBufferDataSize = 2 * 16 * IntermediateBufferHeight * 2; // a multiple of 2 * SourceVertexSize
+const GLsizeiptr OutputVertexBufferDataSize = OutputVertexSize * IntermediateBufferHeight; // i.e. the maximum number of scans of output that can be created between draws
+const GLsizeiptr SourceVertexBufferDataSize = 2 * SourceVertexSize * IntermediateBufferHeight * 2; // a multiple of 2 * SourceVertexSize
}
}