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fluidSim.cpp
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fluidSim.cpp
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// SDL_Project.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "ShaderProgram.hpp"
using namespace std;
#define BUFFER_OFFSET(i) ((char*)NULL + (i))
GLuint All_screen, All_screenVBO;
GLuint boundary,boundaryVBO,boundaryIndexVBO;
GLuint inside, insideVBO, insideIndexVBO;
bool quit = false;
int width = 640;
int height = 480;
GLfloat invWidth = 1.0 / width;
GLfloat invHeight = 1.0 / height;
int main(int argc, char *argv[])
{
#pragma region SDL_FUNCTIONS;
Uint32 start = NULL;
SDL_Init(SDL_INIT_EVERYTHING);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
SDL_Window *window = SDL_CreateWindow("SDL_project", 100, 100, width,height, SDL_WINDOW_SHOWN | SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE );
SDL_GLContext context = SDL_GL_CreateContext(window);
//Init GLEW
GLenum err = glewInit();
if (GLEW_OK != err)
{
cout << "Sorry, but GLEW failed to load.";
return 1;
}
SDL_Event e;
glClearColor(0.4f, 0.4f, 0.4f, 1.0f); //clear screen
#pragma endregion SDL_FUNCTIONS;
#pragma region SHADER_FUNCTIONS
//=============================================================================================
//Shader that contains main logic
unique_ptr<ShaderProgram> MainShader(new ShaderProgram());
MainShader->initFromFiles("MainShader.vert", "MainShader.frag");
MainShader->addAttribute("position");
MainShader->addUniform("mousePos");
//another shader to sample from texture and draw on quadVBO
unique_ptr<ShaderProgram> quadProgram(new ShaderProgram());
quadProgram->initFromFiles("quadProgram.vert", "quadProgram.frag");
quadProgram->addAttribute("quad_vertices");
quadProgram->addUniform("texturesampler");
// quadProgram->addUniform("velocity0");
// quadProgram->addUniform("pressure0");
//advect velocity--1
unique_ptr<ShaderProgram> advectVelocity(new ShaderProgram());
advectVelocity->initFromFiles("MainShader.vert", "advectVelocity.frag");
advectVelocity->addAttribute("position");
advectVelocity->addUniform("velocity1");
advectVelocity->addUniform("Ink");
//advect velocity boundary--2
unique_ptr<ShaderProgram> velocityBoundary(new ShaderProgram());
velocityBoundary->initFromFiles("boundary.vert", "velocityBoundary.frag");
velocityBoundary->addAttribute("position");
velocityBoundary->addAttribute("offset");
velocityBoundary->addUniform("velocity1");
//add force--3
unique_ptr<ShaderProgram> addForce(new ShaderProgram());
addForce->initFromFiles("MainShader.vert","addForce.frag");
addForce->addAttribute("position");
addForce->addUniform("mousePos");
addForce->addUniform("differenceLastPos");
addForce->addUniform("velocity0");
//divergence shader--4
unique_ptr<ShaderProgram> divergenceShader(new ShaderProgram());
divergenceShader->initFromFiles("MainShader.vert","divergence.frag");
divergenceShader->addAttribute("position");
divergenceShader->addUniform("velocity0");
//jacobi solver shader --5
unique_ptr<ShaderProgram> jacobiSolver(new ShaderProgram());
jacobiSolver->initFromFiles("MainShader.vert", "jacobiSolver.frag");
jacobiSolver->addAttribute("position");
jacobiSolver->addUniform("pressure0");
jacobiSolver->addUniform("divergence");
//pressure boundary shader --6 this is same as #5 but it acts on boundary only
unique_ptr<ShaderProgram> pressureBoundary(new ShaderProgram());
pressureBoundary->initFromFiles("boundary.vert", "jacobiSolverBoundary.frag");
pressureBoundary->addAttribute("position");
pressureBoundary->addAttribute("offset");
pressureBoundary->addUniform("pressure0");
// pressureBoundary->addUniform("divergence");
//subtract pressure gradient --7
unique_ptr<ShaderProgram> subtractPressureGradient(new ShaderProgram());
subtractPressureGradient->initFromFiles("MainShader.vert","subtractPressureGradient.frag");
subtractPressureGradient->addAttribute("position");
subtractPressureGradient->addUniform("pressure0");
subtractPressureGradient->addUniform("velocity0");
//copy v1 to v0 --8
unique_ptr<ShaderProgram> texCopyShader(new ShaderProgram());
texCopyShader->initFromFiles("MainShader.vert", "texCopyShader.frag");
texCopyShader->addAttribute("position");
texCopyShader->addUniform("velocity1");
#pragma endregion SHADER_FUNCTIONS
#pragma region MESH_DATA
//Create Vertex Array Object
glGenVertexArrays(1, &All_screen);
glBindVertexArray(All_screen);
GLfloat canvas[] = { //DATA
-1.0f,-1.0f,
-1.0f, 1.0f,
1.0f, -1.0f,
1.0f, -1.0f,
1.0f, 1.0f,
-1.0f, 1.0f
}; //Don't need index data for this peasant mesh!
GLuint All_screenVBO;//VBO for fluid wall
glGenBuffers(1, &All_screenVBO);
glBindBuffer(GL_ARRAY_BUFFER, All_screenVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(canvas), &canvas, GL_STATIC_DRAW);
//Assign attribs
glVertexAttribPointer(MainShader->attribute("position"), 2, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(MainShader->attribute("position"));
glBindVertexArray(0); //unbind VAO
//Create Vertex Array Object
glGenVertexArrays(1, &inside);
glBindVertexArray(inside);
float px = 1.0 / width; px = 10 * px;
float py = 1.0 / height; py = 10 * py;
float x = 1 - px;
float y = 1 - py;
/*Another VBO (this one is for fluid)*/
GLfloat fluidwall[] = { //DATA
-x,-y,
-x, y,
x,-y,
x,-y,
x, y,
-x, y
}; //Don't need index data for this peasant mesh!
GLuint fluid;//VBO for fluid wall
glGenBuffers(1, &fluid);
glBindBuffer(GL_ARRAY_BUFFER, fluid);
glBufferData(GL_ARRAY_BUFFER, sizeof(fluidwall), &fluidwall, GL_STATIC_DRAW);
//Assign attribs
glVertexAttribPointer(MainShader->attribute("position"), 2, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(MainShader->attribute("position"));
glBindVertexArray(0); //unbind VAO
//Another VAO for boundary
glGenVertexArrays(1, &boundary);
glBindVertexArray(boundary);
GLfloat boundaryWall[] = {
//left
-1, 1, 1, 0,
px - 1, 1, 1, 0,
-1, -1, 1, 0,
px - 1, 1, 1, 0,
px - 1, -1, 1, 0,
-1, -1, 1, 0,
//bottom
-1,py-1, 0, 1,
-1, -1, 0, 1,
1, -1, 0, 1,
-1, py - 1, 0, 1,
1, py - 1, 0, 1,
1, -1, 0, 1,
//right
1-px,1, -1,0,
1, 1, -1, 0,
1 - px, -1, -1, 0,
1, 1, -1, 0,
1 - px, -1, -1, 0,
1, -1, -1, 0,
//up
-1,1,0,-1,
1, 1, 0, -1,
-1, 1 - py, 0, -1,
1, 1, 0, -1,
1, 1 - py, 0, -1,
-1, 1 - py, 0, -1,
};
GLuint boundaryVBO;//VBO for fluid wall
glGenBuffers(1, &boundaryVBO);
glBindBuffer(GL_ARRAY_BUFFER, boundaryVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(boundaryWall), &boundaryWall, GL_STATIC_DRAW);
//Assign attribs
glVertexAttribPointer(velocityBoundary->attribute("position"), 2, GL_FLOAT, GL_FALSE, 4*sizeof(GL_FLOAT), 0);
glEnableVertexAttribArray(velocityBoundary->attribute("position"));
glVertexAttribPointer(velocityBoundary->attribute("offset"), 2, GL_FLOAT, GL_FALSE, 4*sizeof(GL_FLOAT), BUFFER_OFFSET(2*sizeof(GL_FLOAT)));
glEnableVertexAttribArray(velocityBoundary->attribute("offset"));
glBindVertexArray(0); //unbind VAO
#pragma endregion MESH_DATA
#pragma region FBO_FUNCTIONS
GLuint MainFBO;
glGenFramebuffers(1,&MainFBO);
glBindFramebuffer(GL_FRAMEBUFFER, MainFBO);
//now create a texture
GLuint renderTexture;
glGenTextures(1, &renderTexture);
glBindTexture(GL_TEXTURE_2D, renderTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_FLOAT, 0);
//filtering
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
//set renderTexture as our color attachment#0
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT5, renderTexture, 0);
///*
// The depth renderbuffer
GLuint depthbuffer;
glGenTextures(1, &depthbuffer);
glBindTexture(GL_TEXTURE_2D, depthbuffer);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_DEPTH_TEXTURE_MODE, GL_INTENSITY);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT16, width, height, 0, GL_DEPTH_COMPONENT,GL_UNSIGNED_BYTE, 0);
glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, depthbuffer, 0);
//glDrawBuffer(GL_NONE);
//glReadBuffer(GL_NONE);
GLuint Velocity0;
glGenTextures(1, &Velocity0);
glBindTexture(GL_TEXTURE_2D, Velocity0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_FLOAT, 0);
//filtering
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
//set renderTexture as our color attachment#0
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, Velocity0, 0);
GLuint Velocity1;
glGenTextures(1, &Velocity1);
glBindTexture(GL_TEXTURE_2D, Velocity1);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_FLOAT, 0);
//filtering
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
//set renderTexture as our color attachment#1
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, Velocity1, 0);
GLuint Pressure0;
glGenTextures(1, &Pressure0);
glBindTexture(GL_TEXTURE_2D, Pressure0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_FLOAT, 0);
//filtering
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
//set renderTexture as our color attachment#0
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, Pressure0, 0);
GLuint Pressure1;
glGenTextures(1, &Pressure1);
glBindTexture(GL_TEXTURE_2D, Pressure1);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_FLOAT, 0);
//filtering
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
//set renderTexture as our color attachment#0
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT3, Pressure1, 0);
GLuint divergence;
glGenTextures(1, &divergence);
glBindTexture(GL_TEXTURE_2D, divergence);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_FLOAT, 0);
//filtering
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
//set renderTexture as our color attachment#0
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT4, divergence, 0);
//now set the list of draw buffers
GLenum drawBuffers[5] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2, GL_COLOR_ATTACHMENT3,GL_COLOR_ATTACHMENT4};
glDrawBuffers(5, drawBuffers);//this is finally where we tell the driver to draw to this paricular framebuffer
//in case something goes wrong :
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
return false;
glBindFramebuffer(GL_FRAMEBUFFER,0);
//Jacobi_iter_FBO_1 : this FBO will be bound for stages 5 and 6
GLuint Jacobi_iter_FBO_1;
glGenFramebuffers(1, &Jacobi_iter_FBO_1);
glBindFramebuffer(GL_FRAMEBUFFER, Jacobi_iter_FBO_1);
glBindTexture(GL_TEXTURE_2D, divergence);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, divergence, 0);
glBindTexture(GL_TEXTURE_2D, Pressure0);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, Pressure0, 0);
glBindTexture(GL_TEXTURE_2D, Pressure1);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, Pressure1, 0);
GLenum Jacobi_iter_1[3] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2};
glDrawBuffers(3, Jacobi_iter_1);
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
return false;
//Jacobi_iter_FBO_2 : this FBO will be bound for stages 5 and 6
GLuint Jacobi_iter_FBO_2;
glGenFramebuffers(1, &Jacobi_iter_FBO_2);
glBindFramebuffer(GL_FRAMEBUFFER, Jacobi_iter_FBO_2);
glBindTexture(GL_TEXTURE_2D, divergence);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, divergence, 0);
glBindTexture(GL_TEXTURE_2D, Pressure1);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, Pressure1, 0);
glBindTexture(GL_TEXTURE_2D, Pressure0);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, Pressure0, 0);
GLenum Jacobi_iter_2[3] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
glDrawBuffers(3, Jacobi_iter_2);
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
return false;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// The fullscreen quad's VBO
static const GLfloat g_quad_vertex_buffer_data[] = {
-1.0f, -1.0f, 0.0f,
1.0f, -1.0f, 0.0f,
-1.0f, 1.0f, 0.0f,
-1.0f, 1.0f, 0.0f,
1.0f, -1.0f, 0.0f,
1.0f, 1.0f, 0.0f,
};
GLuint quad_vertexbuffer;
glGenBuffers(1, &quad_vertexbuffer);
glBindBuffer(GL_ARRAY_BUFFER, quad_vertexbuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(g_quad_vertex_buffer_data), g_quad_vertex_buffer_data, GL_STATIC_DRAW);
glBindFramebuffer(GL_FRAMEBUFFER, 0);//this is default : draw to screen
#pragma endregion FBO_FUNCTIONS
while (!quit)
{
#pragma region EVENT_HANDLING
while (SDL_PollEvent(&e) != 0)
{
switch (e.type)
{
case SDL_QUIT: //if X windowkey is pressed then quit
quit = true;
case SDL_KEYDOWN : //if ESC is pressed then quit
switch (e.key.keysym.sym)
{
case SDLK_ESCAPE:
quit = true;
break;
case SDLK_w:
std::cout << "W pressed \n";
break;
case SDLK_s:
std::cout << "S pressed \n";
break;
case SDLK_a:
std::cout << "A pressed \n";
break;
case SDLK_d:
std::cout << "D pressed \n";
break;
case SDLK_q:
std::cout << "Q pressed \n";
break;
case SDLK_e:
std::cout << "E pressed \n";
break;
}
break;
case SDL_MOUSEMOTION:
std::cout << "mouse moved by x=" << e.motion.xrel << " y=" << e.motion.yrel << "\n";
break;
}
}
#pragma endregion EVENT_HANDLING
#pragma region RTT_MAIN
/*/ THIS BLOCK IS FOR TESTING ONLY. Do not remove.
glBindFramebuffer(GL_FRAMEBUFFER, MainFBO);
MainShader->use();
glUniform2f(MainShader->uniform("mousePos"), (int)e.motion.x, (int)e.motion.y);
glBindVertexArray(All_screen);
glDrawArrays(GL_TRIANGLES, 0, 6);
glBindVertexArray(0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
*/
//Render to out custom MainFBO
glBindFramebuffer(GL_FRAMEBUFFER, MainFBO);
//stage 1------------------------------Force addition
addForce->use();
//we need to do the following because unfortunately uniforms cannot be bound to VAOs
glUniform2f(addForce->uniform("mousePos"), (int)e.motion.x, (int)e.motion.y);
glUniform2f(addForce->uniform("differenceLastPos"), (int)e.motion.xrel, (int)e.motion.yrel);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, Velocity0); //add V0 as input texture
glUniform1i(addForce->uniform("velocity0"), 0);
glBindVertexArray(inside);
//2nd draw call
glDrawArrays(GL_TRIANGLES, 0, 6);
glBindVertexArray(0);
glBindTexture(GL_TEXTURE_2D, 0);
//stage 2--------------------------------Advection
advectVelocity->use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, Velocity1);
glUniform1i(advectVelocity->uniform("velocity1"), 0);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, Velocity1);
glUniform1i(advectVelocity->uniform("Ink"), 1);
glBindVertexArray(inside);
//1st draw call
glDrawArrays(GL_TRIANGLES,0,6);
glBindVertexArray(0);//unbind VAO
glBindTexture(GL_TEXTURE_2D, 0);
// glBindFramebuffer(GL_FRAMEBUFFER, 0);
//stage 3-----------------------------boundary for velocity
glBindVertexArray(boundary);
velocityBoundary->use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, Velocity1);
glUniform1i(velocityBoundary->uniform("velocity1"),0);
glBindVertexArray(boundary);
glDrawArrays(GL_TRIANGLES, 0, 24);
glBindVertexArray(0);//unbind VAO
glBindTexture(GL_TEXTURE_2D, 0);
//stage 4--------------------------------divergence calculation
divergenceShader->use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, Velocity0);
glUniform1i(divergenceShader->uniform("velocity0"), 0);
glBindVertexArray(inside);
//4th draw call
glDrawArrays(GL_TRIANGLES, 0, 6);
glBindVertexArray(0);
glBindTexture(GL_TEXTURE_2D, 0);
//stage 5--------------------------Pressure computation
auto tempFBO = Jacobi_iter_FBO_1;
auto tempPressure = Pressure0;
for (auto i = 0; i < 10; i++)
{
glBindFramebuffer(GL_FRAMEBUFFER, tempFBO);
jacobiSolver->use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, divergence);
glUniform1i(jacobiSolver->uniform("divergence"), 0);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, tempPressure);
glUniform1i(jacobiSolver->uniform("pressure0"), 1);
glBindVertexArray(inside);
glDrawArrays(GL_TRIANGLES, 0, 6);
//Stage 6----------------------------------Pressure boundary
pressureBoundary->use();
glBindVertexArray(boundary);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, Pressure0);
glUniform1i(pressureBoundary->uniform("pressure0"), 0);
glDrawArrays(GL_TRIANGLES, 0, 24);
glBindVertexArray(0);
glBindTexture(GL_TEXTURE_2D, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
//swap pressure textures
tempPressure = Pressure1;
Pressure1 = Pressure0;
Pressure0 = tempPressure;
//swap FBOs
tempFBO = Jacobi_iter_FBO_2;
Jacobi_iter_FBO_2 = Jacobi_iter_FBO_1;
Jacobi_iter_FBO_1 = tempFBO;
}
//stage 6----------------Subtraction of pressure gradient to get divergence free velocity
glBindFramebuffer(GL_FRAMEBUFFER, MainFBO);
subtractPressureGradient->use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, Pressure0);
glUniform1i(subtractPressureGradient->uniform("pressure0"), 0);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, Velocity0);
glUniform1i(subtractPressureGradient->uniform("velocity0"), 1);
glBindVertexArray(inside);
glDrawArrays(GL_TRIANGLES, 0, 6);
glBindVertexArray(0);
glBindTexture(GL_TEXTURE_2D, 0);
//stage 7---- copy v1 to v0
texCopyShader->use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, Velocity1);
glUniform1i(texCopyShader->uniform("velocity1"), 0);
glBindVertexArray(inside);
glDrawArrays(GL_TRIANGLES, 0, 6);
glBindVertexArray(0);
glBindTexture(GL_TEXTURE_2D, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
#pragma endregion RTT_MAIN
#pragma region DRAW_TO_SCREEN
//--------------------------------------------------------------------------------------
//By now we have successfully rendered to our texture. We will now draw on screen
glBindFramebuffer(GL_FRAMEBUFFER,0);
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
//use our quad shader
quadProgram->use();
//Bind out texture in texture unit #0
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, Velocity0);
glUniform1i(quadProgram->uniform("texturesampler"),0);
// glActiveTexture(GL_TEXTURE1);
// glBindTexture(GL_TEXTURE_2D, Pressure0);
// glUniform1i(quadProgram->uniform("pressure0"), 1);
//1st attribute : quad vertices
// glEnableVertexAttribArray(0); //note that this corresponds to the layout=0 in shader
// glBindBuffer(GL_ARRAY_BUFFER,quad_vertexbuffer);
/* glVertexAttribPointer(
0, // attribute 0. No particular reason for 0, but must match the layout in the shader.
3, // size
GL_FLOAT, // type
GL_FALSE, // normalized?
0, // stride
0 // array buffer offset
);
*/
glBindVertexArray(All_screen);
glDrawArrays(GL_TRIANGLES, 0, 6);
glBindVertexArray(0);
//glDisableVertexAttribArray(0);
#pragma endregion DRAW_TO_SCREEN
SDL_GL_SwapWindow(window);
// if (1000 / FPS > SDL_GetTicks() - start)
// SDL_Delay(1000 / FPS - (SDL_GetTicks() - start));
}
SDL_GL_DeleteContext(context);
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}