refractor add source shader

README.md

@@ -22,6 +22,10 @@
 
 - [ ] Need to implement the glfw mouse button callback to make sure glfw send the mouse event to the imgui
 
+### 2024.11.24
+
+- [ ] interpolate the color
+
 
 ## Bugs & Questions
 
@@ -85,7 +89,9 @@ In the file `bgfxToolUtils.cmake`, comment the line `list(APPEND PROFILES s_4_0)
 
 The origin of gl_FragCoord is bottom left, however the origin of glfwGetCursorPos() is top left
 
-6. uniforms structure
+**6. uniforms**
+
+- Uniform structure
 
 If you want to send a struct uniform, for example:
 
@@ -121,10 +127,20 @@ void init(data* _data) {
 }
 ```
 
+- Uniform data
+
+the value you sent to the uniform must be **represent as float**, which means for example:
+
+```cpp
+_data = 0.0f; // Correct
+_data = 0.0;  // false, will be consider as double
+```
+
 7. Framerate issues
 
 I'm not sure why the frame rate in this project changes with the display's maximum refresh rate. For example, with a 60Hz monitor, the frame rate is capped at 60, but when I switch to a 140Hz monitor, it reaches 140. Disabling V-Sync in the NVIDIA control panel under 3D settings unlocks the frame rate limit.
 
 8. `.sh` file doesn't update after modified it
 
 You should update the shader, for example, add some comments, in order to make the `bgfx` rebuild the shader.
+

examples/fluidSim/fluidSim.cpp

@@ -2,7 +2,10 @@
 #include <memory>
 #include <utils/common.hpp>
 
+#include "GLFW/glfw3.h"
 #include "bgfx/bgfx.h"
+#include "bx/string.h"
+#include "gleq.hpp"
 #include "velocityField.hpp"
 
 enum ViewportType
@@ -50,6 +53,7 @@ static const uint16_t quadIndices[] = {
 float lastFrame = 0.0f;
 double lastMousePosX = 0.0f;
 double lastMousePosY = 0.0f;
+bool isPressed = false;
 
 bool densityEnable = false;
 bool velocityAdvectEnable = false;
@@ -84,7 +88,8 @@ class ExampleFluidSim : public shift::AppBaseGLFW
 
             _quadProgram = shift::loadProgram({"quad_vs.sc", "quad_fs.sc"});
 
-            velocity = new VelocityField();
+            velocity = new VelocityField(getWidth(), getHeight(), 0.02f, 10.0f);
+
             velocity->dispatch(ProgramType::reset, 0);
         }
     }
@@ -125,6 +130,8 @@ class ExampleFluidSim : public shift::AppBaseGLFW
             bgfx::setVertexBuffer(0, _vbhQuad);
             bgfx::setIndexBuffer(_ibhQuad);
             bgfx::setBuffer(0, velocity->getBufferHandle(BufferType::isFluid), bgfx::Access::Read);
+            bgfx::setBuffer(1, velocity->getBufferHandle(BufferType::curVelX), bgfx::Access::Read);
+            bgfx::setBuffer(2, velocity->getBufferHandle(BufferType::curVelY), bgfx::Access::Read);
             // check https://bkaradzic.github.io/bgfx/bgfx.html#_CPPv4N4bgfx7Encoder8setStateE8uint64_t8uint32_t
             bgfx::setState(BGFX_STATE_DEFAULT);
             bgfx::submit(0, _quadProgram);
@@ -138,19 +145,53 @@ class ExampleFluidSim : public shift::AppBaseGLFW
                 {
                 case GLEQ_BUTTON_PRESSED:
                     std::cout << "left button pressed" << std::endl;
+                    isPressed = true;
                     break;
-                case GLEQ_CURSOR_MOVED:
-                    // set up uniforms
-                    double x, y;
-                    glfwGetCursorPos(_window, &x, &y);
-
-                    // for calculating the velocity of the mouse
-                    lastMousePosX = x;
-                    lastMousePosY = y;
 
+                case GLEQ_CURSOR_MOVED: {
+                    if (isPressed)
+                    {
+                        // set up uniforms
+                        double x, y;
+                        glfwGetCursorPos(_window, &x, &y);
+
+                        // calculate the velocity dir
+                        glm::vec2 velDir = glm::vec2(x - lastMousePosX, y - lastMousePosY);
+                        velDir = glm::normalize(velDir);
+
+                        // update uniforms
+                        velocity->updateUniforms(UniformType::mousePosX, x);
+                        velocity->updateUniforms(UniformType::mousePosY, y);
+                        velocity->updateUniforms(UniformType::mouseVelX, velDir.x);
+                        // the origin is in the top left
+                        velocity->updateUniforms(UniformType::mouseVelY, -velDir.y);
+
+                        // for calculating the velocity dir of the mouse
+                        lastMousePosX = _event.pos.x;
+                        lastMousePosY = _event.pos.y;
+
+                        // dispatch shader
+                        velocity->dispatch(ProgramType::addSource, 0);
+                        // Debug info
+                        // std::cout << velDir.x << " " << velDir.y << std::endl;
+                    }
                     break;
+                }
+
                 case GLEQ_BUTTON_RELEASED:
                     std::cout << "left button released" << std::endl;
+                    isPressed = false;
+                    break;
+
+                case GLEQ_KEY_PRESSED:
+                    if (_event.keyboard.key == GLFW_KEY_R)
+                    {
+                        std::cout << "Reset the program" << std::endl;
+                        velocity->dispatch(ProgramType::reset, 0);
+                    }
+                    break;
+
+                case GLEQ_KEY_RELEASED:
                     break;
                 }
 

examples/fluidSim/velocityField.cpp

@@ -6,23 +6,22 @@
 #include "velocityField.hpp"
 #include <intrin.h>
 
-// VelocityField::VelocityField(int width, int height, float dt, float speed)
-VelocityField::VelocityField()
+VelocityField::VelocityField(int _width, int _height, float _dt, float _speed)
 {
     // init uniforms and uniform handle
     _uParams.mousePosX = 3.40e+38; // avoid the origin problem of the addSource compute shader
     _uParams.mousePosY = 3.40e+38;
     _uParams.mouseVelX = 0.0f;
     _uParams.mouseVelY = 0.0f;
     _uParams.radius = 5.0f;
-    _uParams.simResX = SHIFT_DEFAULT_WIDTH;
-    _uParams.simResY = SHIFT_DEFAULT_HEIGHT;
-    _uParams.simResZ = 1;
-    _uParams.persist = false;
-    _uParams.deltaTime = 0.002;
-    _uParams.speed = 75;
+    _uParams.simResX = float(_width);
+    _uParams.simResY = float(_height);
+    _uParams.simResZ = 1.0f;
+    _uParams.persist = float(false);
+    _uParams.deltaTime = _dt;
+    _uParams.speed = _speed;
 
-    _uhParams = bgfx::createUniform("uParams", bgfx::UniformType::Vec4, int(UniformType::count / 4));
+    _uhParams = bgfx::createUniform("uParams", bgfx::UniformType::Vec4, int(UniformType::count / 4) + 1);
 
     // init the compute shader group size
     _groupSizeX = _uParams.simResX / kThreadGroupSizeX;
@@ -46,9 +45,9 @@ VelocityField::VelocityField()
 
     // init compute shaders
     _csReset = shift::loadProgram({"velocity_reset_cs.sc"});
-    //_csAddSource = shift::loadProgram({"velocity_addSource_cs.sc"});
-    //_csAdvect = shift::loadProgram({"velocity_advect_cs.sc"});
-    //_csProject = shift::loadProgram({"velocity_project_cs.sc"});
+    _csAddSource = shift::loadProgram({"velocity_addSource_cs.sc"});
+    _csAdvect = shift::loadProgram({"velocity_advect_cs.sc"});
+    _csProject = shift::loadProgram({"velocity_project_cs.sc"});
 }
 
 VelocityField::~VelocityField()
@@ -72,7 +71,7 @@ void VelocityField::Reset(int _viewID)
     bgfx::setBuffer(2, _curVelX, bgfx::Access::Write);
     bgfx::setBuffer(3, _curVelY, bgfx::Access::Write);
     bgfx::setBuffer(4, _isFluid, bgfx::Access::Write);
-    bgfx::setUniform(_uhParams, &_uParams, int(UniformType::count / 4));
+    bgfx::setUniform(_uhParams, &_uParams, int(UniformType::count / 4) + 1);
     bgfx::dispatch(_viewID, _csReset, _groupSizeX, _groupSizeY, _groupSizeZ);
 }
 
@@ -84,7 +83,7 @@ void VelocityField::AddSource(int _viewID)
     bgfx::setBuffer(3, _curVelY, bgfx::Access::ReadWrite);
     // might need to change the access????
     bgfx::setBuffer(4, _isFluid, bgfx::Access::Read);
-    bgfx::setUniform(_uhParams, &_uParams, int(UniformType::count / 4));
+    bgfx::setUniform(_uhParams, &_uParams, int(UniformType::count / 4) + 1);
     bgfx::dispatch(_viewID, _csAddSource, _groupSizeX, _groupSizeY, _groupSizeZ);
 }
 
@@ -95,7 +94,7 @@ void VelocityField::Advect(int _viewID)
     bgfx::setBuffer(2, _curVelX, bgfx::Access::ReadWrite);
     bgfx::setBuffer(3, _curVelY, bgfx::Access::ReadWrite);
     bgfx::setBuffer(4, _isFluid, bgfx::Access::Read);
-    bgfx::setUniform(_uhParams, &_uParams, int(UniformType::count / 4));
+    bgfx::setUniform(_uhParams, &_uParams, int(UniformType::count / 4) + 1);
     bgfx::dispatch(_viewID, _csAdvect, _groupSizeX, _groupSizeY, _groupSizeZ);
 }
 
@@ -106,6 +105,6 @@ void VelocityField::Project(int _viewID)
     bgfx::setBuffer(2, _curVelX, bgfx::Access::ReadWrite);
     bgfx::setBuffer(3, _curVelY, bgfx::Access::ReadWrite);
     bgfx::setBuffer(4, _isFluid, bgfx::Access::Read);
-    bgfx::setUniform(_uhParams, &_uParams, int(UniformType::count / 4));
+    bgfx::setUniform(_uhParams, &_uParams, int(UniformType::count / 4) + 1);
     bgfx::dispatch(_viewID, _csProject, _groupSizeX, _groupSizeY, _groupSizeZ);
 }

examples/fluidSim/velocityField.hpp

@@ -70,8 +70,8 @@ class VelocityField
     void Project(int _viewID);
 
   public:
-    // VelocityField(int width, int height, float dt, float speed);
-    VelocityField();
+    VelocityField(int _width, int _height, float _dt, float _speed);
+    // VelocityField();
     ~VelocityField();
 
   public:
@@ -109,6 +109,7 @@ class VelocityField
             break;
         case BufferType::curVelY:
             return _curVelY;
+            break;
         case BufferType::isFluid:
             return _isFluid;
             break;
@@ -122,10 +123,13 @@ class VelocityField
         {
         case ProgramType::reset:
             return _csReset;
+            break;
         case ProgramType::advect:
             return _csAdvect;
+            break;
         case ProgramType::project:
             return _csProject;
+            break;
         }
         return BGFX_INVALID_HANDLE;
     }

ext/gleq/gleq.hpp

@@ -64,8 +64,6 @@ extern "C"
         GLEQ_CODEPOINT_INPUT,
         GLEQ_MONITOR_CONNECTED,
         GLEQ_MONITOR_DISCONNECTED,
-        GLEQ_IMGUI_BUTTON_PPRESSED,
-        GLEQ_IMGUI_BUTTON_RELEASED,
 #if GLFW_VERSION_MINOR >= 1
         GLEQ_FILE_DROPPED,
 #endif
@@ -145,8 +143,6 @@ extern "C"
 }
 #endif
 
-#define GLEQ_IMPLEMENTATION
-
 #ifdef GLEQ_IMPLEMENTATION
 
 #include <assert.h>

shaders/examples/fluidSim/quad_fs.sc

@@ -6,11 +6,22 @@ $input v2f_texCoord0
 #define bufferSize 512
 
 BUFFER_RO(_isFluid, float, 0);
-
+BUFFER_RO(_curVelX, float, 1);
+BUFFER_RO(_curVelY, float, 2);
 
 void main() {
 	int index = int(gl_FragCoord.x) + bufferSize * int(gl_FragCoord.y);
 
-    //gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
-    gl_FragColor = vec4(1-_isFluid[index].xxx, 1.0);
+    if(_isFluid[index] == 0) {
+      // draw the boundary
+      gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
+    } else {
+      // draw the velocity
+      float colorX = _curVelX[index] == 0 ? 0 : _curVelX[index] * 0.5 + 0.5;
+      float colorY = _curVelY[index] == 0 ? 0 : _curVelY[index] * 0.5 + 0.5;
+      gl_FragColor = vec4(0.0, colorX, colorY, 1.0);
+
+      // Debug
+      //gl_FragColor = vec4(1.0,0.0,0.0,1.0);
+    }
 }

shaders/examples/fluidSim/velocity_addSource_cs.sc

@@ -1,7 +1,22 @@
 #include "../../utils/bgfx_compute.sh"
 #include "velocity_uniforms.sh"
 
+BUFFER_RO(_prevVelX, float, 0);
+BUFFER_RO(_prevVelY, float, 1);
+BUFFER_RW(_curVelX, float, 2);
+BUFFER_RW(_curVelY, float, 3);
+BUFFER_WO(_isFluid, float, 4);
 
 NUM_THREADS(8, 8, 1)
 void main() {
+  uvec2 pos = gl_GlobalInvocationID.xy;
+  uint index = Index2D(pos.x, pos.y, uSimResX);
+
+  // calculate the distance from the current cell to the mouse position
+  float dis = distance(pos, vec2(uMousePosX, uSimResY - uMousePosY));
+
+  if(dis < uRadius) {
+    _curVelX[index] += uMouseVelX * uDeltaTime * uSpeed + _prevVelX[index];
+    _curVelY[index] += uMouseVelY * uDeltaTime * uSpeed + _prevVelY[index];
+  }
 }

shaders/examples/fluidSim/velocity_reset_cs.sc

@@ -11,15 +11,15 @@ NUM_THREADS(8, 8, 1)
 void main() {
     // init the density field and velocity field
     vec2 pos = gl_GlobalInvocationID.xy;
-    uint index = Index2D(uint(pos.x), uint(pos.y), 512.0);
+    uint index = Index2D(uint(pos.x), uint(pos.y), uSimResX);
 
     _prevVelX[index] = 0.0;
     _prevVelY[index] = 0.0;
     _curVelX[index] = 0.0;
     _curVelY[index] = 0.0;
 
     // determine if the current grid is inside the sim area
-    if(pos.x > 100 && pos.y > 100 && pos.x < uSimResX - 100 && pos.y < uSimResY - 100) {
+    if(pos.x > 0 && pos.y > 0 && pos.x < uSimResX - 1 && pos.y < uSimResY - 1) {
         _isFluid[index] = 1.0;
         return;
     }

shaders/examples/fluidSim/velocity_uniforms.sh

@@ -14,10 +14,16 @@ uniform vec4 uParams[3];
 #define uDeltaTime              uParams[2].y
 #define uSpeed                  uParams[2].z
 
+#define LEFT(idx) ((idx) - 1)
+#define RIGHT(idx) ((idx) + 1)
+#define UP(idx) ((idx) + uSimResX)
+#define DOWN(idx) ((idx) - uSimResX)
+
 uint Index2D(uint x, uint y, float simResX) {
     return x + uint(simResX) * y;
 }
 
 uint Index3D(uint x, uint y, uint z, float simResX, float simResY) {
     return 0;
 }
+