From f0b536ac93b3a9a49dfff8a7637f09b153a3b955 Mon Sep 17 00:00:00 2001
From: Adrian Kummerlaender
Date: Fri, 22 Feb 2019 21:49:07 +0100
Subject: Improvise interactive wall drawing
Internal wall cells need to be disabled to prevent delayed propagation
of the reflected populations.
This is just quickly thrown together - both the visual drawing and the backend's
material handling remain to be improved.
---
CMakeLists.txt | 1 +
src/buffer/vertex/material_buffer.cc | 51 ++++++++++++++++++++++++
src/buffer/vertex/material_buffer.h | 18 +++++++++
src/glfw/window.cc | 11 ++++--
src/glfw/window.h | 2 +-
src/main.cc | 7 +++-
src/shader/code/collide.glsl | 75 +++++++++++++++++++++++++-----------
src/shader/code/stream.glsl | 15 ++++++--
src/shader/code/vertex.glsl | 16 +++++---
9 files changed, 158 insertions(+), 38 deletions(-)
create mode 100644 src/buffer/vertex/material_buffer.cc
create mode 100644 src/buffer/vertex/material_buffer.h
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5b8b141..70f0107 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,6 +17,7 @@ add_executable(
src/shader/wrap/graphic_shader.cc
src/buffer/vertex/lattice_cell_buffer.cc
src/buffer/vertex/fluid_cell_buffer.cc
+ src/buffer/vertex/material_buffer.cc
)
target_link_libraries(
diff --git a/src/buffer/vertex/material_buffer.cc b/src/buffer/vertex/material_buffer.cc
new file mode 100644
index 0000000..82ccea2
--- /dev/null
+++ b/src/buffer/vertex/material_buffer.cc
@@ -0,0 +1,51 @@
+#include "material_buffer.h"
+
+#include <vector>
+
+MaterialBuffer::MaterialBuffer(GLuint nX, GLuint nY):
+ _nX(nX), _nY(nY) {
+ glGenVertexArrays(1, &_array);
+ glGenBuffers(1, &_buffer);
+
+ glBindVertexArray(_array);
+ glBindBuffer(GL_ARRAY_BUFFER, _buffer);
+
+ std::vector<GLint> data(nX*nY, GLint{1});
+
+ for ( int x = 0; x < nX; ++x ) {
+ data[ 0*nX + x] = 0;
+ data[(nY-1)*nX + x] = 0;
+ }
+ for ( int y = 0; y < nY; ++y ) {
+ data[y*nX + 0] = 0;
+ data[y*nX + nX-1] = 0;
+ }
+
+ for ( int x = 1; x < nX-1; ++x ) {
+ data[ 1*nX + x] = 2;
+ data[(nY-2)*nX + x] = 2;
+ }
+ for ( int y = 1; y < nY-1; ++y ) {
+ data[y*nX + 1] = 2;
+ data[y*nX + nX-2] = 2;
+ }
+
+ glBufferData(
+ GL_ARRAY_BUFFER,
+ data.size() * sizeof(GLint),
+ data.data(),
+ GL_STATIC_DRAW
+ );
+
+ glEnableVertexAttribArray(0);
+ glVertexAttribPointer(0, 1, GL_INT, GL_FALSE, 0, nullptr);
+}
+
+MaterialBuffer::~MaterialBuffer() {
+ glDeleteBuffers(1, &_buffer);
+ glDeleteVertexArrays(1, &_array);
+}
+
+GLuint MaterialBuffer::getBuffer() const {
+ return _buffer;
+}
diff --git a/src/buffer/vertex/material_buffer.h b/src/buffer/vertex/material_buffer.h
new file mode 100644
index 0000000..eccf008
--- /dev/null
+++ b/src/buffer/vertex/material_buffer.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <GL/glew.h>
+
+class MaterialBuffer {
+private:
+ const GLuint _nX;
+ const GLuint _nY;
+
+ GLuint _array;
+ GLuint _buffer;
+
+public:
+ MaterialBuffer(GLuint nX, GLuint nY);
+ ~MaterialBuffer();
+
+ GLuint getBuffer() const;
+};
diff --git a/src/glfw/window.cc b/src/glfw/window.cc
index 98890b7..4f14501 100644
--- a/src/glfw/window.cc
+++ b/src/glfw/window.cc
@@ -37,14 +37,19 @@ int Window::getHeight() const {
return _height;
}
-std::tuple<bool,int,int> Window::getMouse() const {
- const bool clicked = glfwGetMouseButton(_handle, GLFW_MOUSE_BUTTON_LEFT) == GLFW_PRESS;
+std::tuple<int,int,int> Window::getMouse() const {
+ int state = 0;
+ if ( glfwGetMouseButton(_handle, GLFW_MOUSE_BUTTON_LEFT) == GLFW_PRESS ) {
+ state = 1;
+ } else if ( glfwGetMouseButton(_handle, GLFW_MOUSE_BUTTON_RIGHT) == GLFW_PRESS ) {
+ state = 2;
+ }
double x, y;
glfwGetCursorPos(_handle, &x, &y);
return std::make_tuple(
- clicked,
+ state,
x - int(getWidth()/2),
int(getHeight()/2 - y)
);
diff --git a/src/glfw/window.h b/src/glfw/window.h
index af7ba4d..143d457 100644
--- a/src/glfw/window.h
+++ b/src/glfw/window.h
@@ -27,7 +27,7 @@ public:
int getWidth() const;
int getHeight() const;
- std::tuple<bool,int,int> getMouse() const;
+ std::tuple<int,int,int> getMouse() const;
KeyWatcher getKeyWatcher(int key) const;
diff --git a/src/main.cc b/src/main.cc
index 3048979..0a400a5 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -10,6 +10,7 @@
#include "buffer/vertex/fluid_cell_buffer.h"
#include "buffer/vertex/lattice_cell_buffer.h"
+#include "buffer/vertex/material_buffer.h"
#include "shader/wrap/graphic_shader.h"
#include "shader/wrap/compute_shader.h"
@@ -66,6 +67,7 @@ int renderWindow() {
std::unique_ptr<LatticeCellBuffer> lattice_a;
std::unique_ptr<LatticeCellBuffer> lattice_b;
std::unique_ptr<FluidCellBuffer> fluid;
+ std::unique_ptr<MaterialBuffer> geometry;
std::unique_ptr<ComputeShader> collide_shader;
std::unique_ptr<ComputeShader> stream_shader;
@@ -77,6 +79,7 @@ int renderWindow() {
lattice_a = std::make_unique<LatticeCellBuffer>(nX, nY);
lattice_b = std::make_unique<LatticeCellBuffer>(nX, nY);
fluid = std::make_unique< FluidCellBuffer>(nX, nY);
+ geometry = std::make_unique< MaterialBuffer>(nX, nY);
collide_shader = std::make_unique<ComputeShader>(COLLIDE_SHADER_CODE);
stream_shader = std::make_unique<ComputeShader>(STREAM_SHADER_CODE);
@@ -94,8 +97,8 @@ int renderWindow() {
auto pause_key = window.getKeyWatcher(GLFW_KEY_SPACE);
- auto tick_buffers = { lattice_a->getBuffer(), lattice_b->getBuffer(), fluid->getBuffer() };
- auto tock_buffers = { lattice_b->getBuffer(), lattice_a->getBuffer(), fluid->getBuffer() };
+ auto tick_buffers = { lattice_a->getBuffer(), lattice_b->getBuffer(), fluid->getBuffer(), geometry->getBuffer() };
+ auto tock_buffers = { lattice_b->getBuffer(), lattice_a->getBuffer(), fluid->getBuffer(), geometry->getBuffer() };
window.render([&](bool window_size_changed) {
if ( pause_key.wasClicked() ) {
diff --git a/src/shader/code/collide.glsl b/src/shader/code/collide.glsl
index cb950cb..b58bec3 100644
--- a/src/shader/code/collide.glsl
+++ b/src/shader/code/collide.glsl
@@ -3,9 +3,10 @@ static const std::string COLLIDE_SHADER_CODE = R"(
layout (local_size_x = 1, local_size_y = 1) in;
-layout (std430, binding=1) buffer bufferCollide{ float collideCells[]; };
-layout (std430, binding=2) buffer bufferStream{ float streamCells[]; };
-layout (std430, binding=3) buffer bufferFluid{ float fluidCells[]; };
+layout (std430, binding=1) buffer bufferCollide { float collideCells[]; };
+layout (std430, binding=2) buffer bufferStream { float streamCells[]; };
+layout (std430, binding=3) buffer bufferFluid { float fluidCells[]; };
+layout (std430, binding=4) buffer bufferGeometry { int materialCells[]; };
/// external influence
@@ -76,6 +77,22 @@ void setFluid(uint x, uint y, vec2 v, float d) {
fluidCells[idx + 2] = d;
}
+int getMaterial(uint x, uint y) {
+ return materialCells[nX*y + x];
+}
+
+void setMaterial(uint x, uint y, int m) {
+ materialCells[nX*y + x] = m;
+}
+
+void disableFluid(uint x, uint y) {
+ const uint idx = indexOfFluidVertex(x, y);
+ fluidCells[idx + 0] = 0.0;
+ fluidCells[idx + 1] = 0.0;
+ fluidCells[idx + 2] = -2.0;
+}
+
+
/// Moments
float density(uint x, uint y) {
@@ -103,21 +120,19 @@ float equilibrium(float d, vec2 v, int i, int j) {
/// Determine external influence
float getExternalPressureInflux(uint x, uint y) {
- if ( mouseState == 1 && norm(vec2(x,y) - mousePos) < 4 ) {
+ if ( mouseState == 1 && norm(vec2(x,y) - mousePos) < 2 ) {
return 1.5;
} else {
return 0.0;
}
}
-/// Domain description
-
-bool isEndOfWorld(uint x, uint y) {
- return x == 0 || x == nX-1 || y == 0 || y == nY-1;
-}
-
-bool isOuterWall(uint x, uint y) {
- return x == 1 || x == nX-2 || y == 1 || y == nY-2;
+bool getExternalWallRequest(uint x, uint y) {
+ if ( mouseState == 2 && norm(vec2(x,y) - mousePos) < 4 ) {
+ return true;
+ } else {
+ return false;
+ }
}
/// Actual collide kernel
@@ -130,22 +145,38 @@ void main() {
return;
}
- if ( isEndOfWorld(x,y) ) {
- return;
+ if ( getExternalWallRequest(x,y) ) {
+ setMaterial(x,y,2);
+ disableFluid(x,y);
}
- if ( isOuterWall(x,y) ) {
- return;
+ const int material = getMaterial(x,y);
+
+ if ( material == 2 ) {
+ int wallNeighbors = 0;
+ for ( int i = -1; i <= 1; ++i ) {
+ for ( int j = -1; j <= 1; ++j ) {
+ const int material = getMaterial(x+i,y+j);
+ if ( material == 0 || material == 2 ) {
+ ++wallNeighbors;
+ }
+ }
+ }
+ if ( wallNeighbors == 9 ) {
+ setMaterial(x,y,0);
+ }
}
- const float d = max(getExternalPressureInflux(x,y), density(x,y));
- const vec2 v = velocity(x,y,d);
+ if ( material == 1 ) { // fluid
+ const float d = max(getExternalPressureInflux(x,y), density(x,y));
+ const vec2 v = velocity(x,y,d);
- setFluid(x,y,v,d);
+ setFluid(x,y,v,d);
- for ( int i = -1; i <= 1; ++i ) {
- for ( int j = -1; j <= 1; ++j ) {
- set(x,y,i,j, get(x,y,i,j) + omega * (equilibrium(d,v,i,j) - get(x,y,i,j)));
+ for ( int i = -1; i <= 1; ++i ) {
+ for ( int j = -1; j <= 1; ++j ) {
+ set(x,y,i,j, get(x,y,i,j) + omega * (equilibrium(d,v,i,j) - get(x,y,i,j)));
+ }
}
}
}
diff --git a/src/shader/code/stream.glsl b/src/shader/code/stream.glsl
index 345127d..a8aec1d 100644
--- a/src/shader/code/stream.glsl
+++ b/src/shader/code/stream.glsl
@@ -3,8 +3,9 @@ static const std::string STREAM_SHADER_CODE = R"(
layout (local_size_x = 1, local_size_y = 1) in;
-layout (std430, binding=1) buffer bufferCollide{ float collideCells[]; };
-layout (std430, binding=2) buffer bufferStream{ float streamCells[]; };
+layout (std430, binding=1) buffer bufferCollide { float collideCells[]; };
+layout (std430, binding=2) buffer bufferStream { float streamCells[]; };
+layout (std430, binding=4) buffer bufferGeometry { int materialCells[]; };
/// LBM constants
@@ -33,6 +34,10 @@ void set(uint x, uint y, int i, int j, float v) {
streamCells[indexOfLatticeCell(x,y) + indexOfDirection(i,j)] = v;
}
+int getMaterial(uint x, uint y) {
+ return materialCells[nX*y + x];
+}
+
/// Domain description
bool isEndOfWorld(uint x, uint y) {
@@ -63,11 +68,13 @@ void main() {
return;
}
- if ( isEndOfWorld(x,y) ) {
+ const int material = getMaterial(x,y);
+
+ if ( material == 0 ) {
return;
}
- if ( isOuterWall(x,y) ) {
+ if ( material == 2 ) {
bounceBack(x,y);
}
diff --git a/src/shader/code/vertex.glsl b/src/shader/code/vertex.glsl
index 700a9b7..52d9403 100644
--- a/src/shader/code/vertex.glsl
+++ b/src/shader/code/vertex.glsl
@@ -10,7 +10,7 @@ out VS_OUT {
uniform uint nX;
uniform uint nY;
-const float displayAmplifier = 5.0;
+const float displayAmplifier = 50.0;
float unit(float x) {
return 1.0/(1.0+exp(-x));
@@ -42,10 +42,14 @@ void main() {
1.
);
- vs_out.color = mix(
- vec3(-0.5, 0.0, 1.0),
- vec3( 1.0, 0.0, 0.0),
- displayAmplifier * VertexPosition.z * norm(VertexPosition.xy)
- );
+ if ( VertexPosition.z < -1.0 ) {
+ vs_out.color = vec3(0.0, 0.0, 0.0);
+ } else {
+ vs_out.color = mix(
+ vec3(-0.5, 0.0, 1.0),
+ vec3( 1.0, 0.0, 0.0),
+ displayAmplifier * VertexPosition.z * norm(VertexPosition.xy)
+ );
+ }
}
)";
--
cgit v1.2.3