Particles, first pass

src/viewer/simpleViewer.cpp

@@ -32,6 +32,7 @@
 #include <QCoreApplication>
 
 #include <iostream>
+#include <ctime>
 #include <stack>
 #include <QMouseEvent>
 #include <typeinfo>
@@ -54,6 +55,8 @@ namespace
 	const int numVerticesSphere = numColSphere * numRowSphere + 2;
 	const int numTriSphere = numColSphere*(numRowSphere-1)*2 + 2*numColSphere;
 
+	const GLuint particleLimit = 1024;
+
 	int m_lDirectionLocation;
 	int m_normalMatrixLoc;
 
@@ -241,18 +244,60 @@ void Viewer::draw()
 	modelStack.push(modelViewMatrix);
 	root.accept(*this);
 
-    drawTool();
+	drawParticles();
-
 	drawUi();
 
 	sunRotate.setToIdentity();
 	//float rotAngle = (frame * angle_mult) % 360;
 }
 
+void Viewer::drawTool() {
+	objShader->bind();
+
+	// Get projection and camera transformations
+	QMatrix4x4 modelViewMatrix;
+
+	//camera()->getModelViewMatrix(modelViewMatrix);
+
+	QMatrix4x4 toolboxPos = QMatrix4x4();
+	float swingMult = 1;
+	//scale.translate(QVector3D(0,1.5,0));
+	toolboxPos.translate(0.6, -0.25, -1.6);
+	toolboxPos.rotate(-100, 0, 1, 0);
+	if(swing.active) {
+		swingMult = 0.5 + 0.5 * cos(fmin(swing.length, frame - swing.startFrame) * 2 * M_PI / swing.length);
+		if(frame - swing.startFrame > swing.length) {
+			swing.active = false;
+		}
+	}
+	toolboxPos.rotate(swingMult * -65, 0, 0, 1);
+	toolboxPos.scale(0.06);
+
+	objShader->setUniformValue(o_u_mvMatrix, modelViewMatrix * toolboxPos);
+	objShader->setUniformValue(o_u_nmMatrix, modelViewMatrix.normalMatrix());
+
+	// Draw the meshes
+	for (unsigned int i=0; i<_meshesGL.size(); ++i)
+	{
+		// Set its material properties
+		objShader->setUniformValue(o_u_kd, _meshesGL[i].diffuse);
+		objShader->setUniformValue(o_u_ks, _meshesGL[i].specular);
+		objShader->setUniformValue(o_u_kn, _meshesGL[i].specularExponent);
+		objShader->setUniformValue(o_u_ka, _meshesGL[i].alpha);
+
+		// Draw the mesh
+		glBindVertexArray(_meshesGL[i].vao);
+		glDrawArrays(GL_TRIANGLES, 0, _meshesGL[i].numVertices);
+	}
+}
+
 void Viewer::drawUi(){
+	glClear(GL_DEPTH_BUFFER_BIT); // make ui always on top
+
+	drawTool();
+
 	m_program->bind();
 	glCullFace(GL_BACK);
-	glClear(GL_DEPTH_BUFFER_BIT); // make ui always on top
 
 	QMatrix4x4 projectionMatrix;
 	QMatrix4x4 uiViewMatrix;
@@ -284,6 +329,35 @@ void Viewer::drawUi(){
 
 }
 
+void Viewer::drawParticles(){
+	m_program->bind();
+
+	QMatrix4x4 projectionMatrix;
+	QMatrix4x4 modelViewMatrix;
+	camera()->getProjectionMatrix(projectionMatrix);
+	camera()->getModelViewMatrix(modelViewMatrix);
+
+
+	glBindVertexArray(m_VAOs[VAO_Particle]);
+	glBindBuffer(GL_ARRAY_BUFFER, VBO_Particle);
+	glBindBuffer(GL_ARRAY_BUFFER, VBO_Particle_Positions);
+	glBindBuffer(GL_ARRAY_BUFFER, VBO_Particle_Colors);
+
+
+
+	glActiveTexture(GL_TEXTURE0);
+	TexturePrograms[1]->bind();
+
+	m_program->setUniformValue(m_isSkyLoc, true);
+	m_program->setUniformValue(m_mvMatrixLocation, modelViewMatrix);
+	m_program->setUniformValue(m_normalMatrixLoc, modelViewMatrix.normalMatrix());
+	m_program->setUniformValue(m_colorLocation, QColor(255, 255, 255, 255));
+	m_program->setUniformValue(m_drawTextLoc, false);
+	m_program->setUniformValue(m_isLightLoc, true);
+
+	glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, particleLimit);
+}
+
 void Viewer::mouseMoveEvent(QMouseEvent* e) {
 	//cout << "Viewer::mouseMoveEvent(QMouseEvent* e)" << endl;
 	// Normal QGLViewer behavior.
@@ -835,32 +909,8 @@ void Viewer::initGeometries()
 	glVertexAttribPointer(s_vUvLocation, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(offsetUV));
 	glEnableVertexAttribArray(s_vUvLocation);
 
-	/*GLsizeiptr offsetVertices = 0;
-	GLsizeiptr offsetNormals = sizeof(verticesCube);
-	GLsizeiptr offsetUV = offsetNormals + sizeof(normals);
-	GLsizeiptr dataSize = offsetUV + sizeof(uvs);
-
-
-	glBindVertexArray(m_VAOs[VAO_Cube]);
-	glBindBuffer(GL_ARRAY_BUFFER, m_Buffers[VBO_Cube]);
-	glBufferData(GL_ARRAY_BUFFER, dataSize, NULL, GL_STATIC_DRAW);
-
-	glBufferSubData(GL_ARRAY_BUFFER, offsetVertices, sizeof(verticesCube), verticesCube);
-	glBufferSubData(GL_ARRAY_BUFFER, offsetNormals, sizeof(normals), normals);
-	glBufferSubData(GL_ARRAY_BUFFER, offsetUV, sizeof(uvs), uvs);
-
-	glVertexAttribPointer(m_vPositionLocation, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
-	glEnableVertexAttribArray(m_vPositionLocation);
-
-	glVertexAttribPointer(m_vNormalLocation, 3, GL_FLOAT, GL_TRUE, 0, BUFFER_OFFSET(sizeof(offsetNormals)));
-	glEnableVertexAttribArray(m_vNormalLocation);
-
-	glVertexAttribPointer(s_vUvLocation, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(sizeof(offsetUV)));
-	glEnableVertexAttribArray(s_vUvLocation);//*/
-
 	// Fill Sphere VBO
 
-
 	GLsizeiptr offsetSphereV = 0;
 	GLsizeiptr offsetSphereN = offsetSphereV + sizeof(sphereVertices);
 	GLsizeiptr sphereDataSize = offsetSphereN + sizeof(sphereNormals);
@@ -882,6 +932,69 @@ void Viewer::initGeometries()
 
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_Buffers[EBO_Sphere]);
 	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(sphereIndices), sphereIndices, GL_STATIC_DRAW);
+
+
+	// Fill Particle VBO
+	//==============================================================
+	// CODE RÉFÉRENCÉ
+	// http://www.opengl-tutorial.org/intermediate-tutorials/billboards-particles/particles-instancing/
+	//==============================================================
+	GLfloat verticesParticle[] = {
+	 -0.5f, -0.5f, 0.0f,
+	 0.5f, -0.5f, 0.0f,
+	 -0.5f, 0.5f, 0.0f,
+	 0.5f, 0.5f, 0.0f,
+	};
+
+	GLfloat particlePositions[particleLimit][4] = {}; // x, y, z and time, for shader's lifetime calculation
+	GLubyte particleColors[particleLimit][4] = {};
+
+	srand((unsigned int) time(NULL));
+	for(int i = 0; i < particleLimit; i++){
+		double r = rand() / (RAND_MAX);
+		double g = rand() / (RAND_MAX);
+		double b = rand() / (RAND_MAX);
+		particlePositions[i][0] = r*10;
+		particlePositions[i][1] = g*10;
+		particlePositions[i][2] = b*10;
+		particlePositions[i][3] = 0;
+		particleColors[i][0] = r;
+		particleColors[i][1] = g;
+		particleColors[i][2] = b;
+		particleColors[i][3] = 1;
+	}
+
+	glBindVertexArray(m_VAOs[VAO_Particle]);
+	glBindBuffer(GL_ARRAY_BUFFER, m_Buffers[VBO_Particle]);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(verticesParticle), verticesParticle, GL_STATIC_DRAW);
+
+	// particle position buffer
+	glBindBuffer(GL_ARRAY_BUFFER, m_Buffers[VBO_Particle_Positions]);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(particlePositions), NULL, GL_STREAM_DRAW);
+	glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(particlePositions), particlePositions);
+
+	// particle color buffer
+	glBindBuffer(GL_ARRAY_BUFFER, m_Buffers[VBO_Particle_Colors]);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(particleColors), NULL, GL_STREAM_DRAW);
+	glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(particleColors), particleColors);
+
+	glVertexAttribPointer(m_vPositionLocation, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+	glEnableVertexAttribArray(m_vPositionLocation);
+
+	glVertexAttribPointer(m_vNormalLocation, 3, GL_FLOAT, GL_TRUE, 0, BUFFER_OFFSET(offsetNormals));
+	glEnableVertexAttribArray(m_vNormalLocation);
+
+	glVertexAttribPointer(s_vUvLocation, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(offsetUV));
+	glEnableVertexAttribArray(s_vUvLocation);//*/
+
+	glVertexAttribDivisor(0, 0); // particles vertices : always reuse the same 4 vertices -> 0
+	glVertexAttribDivisor(1, 1); // positions : one per quad (its center) -> 1
+	glVertexAttribDivisor(2, 1); // color : one per quad -> 1
+
+	//==============================================================
+	// FIN DE CODE RÉFÉRENCÉ
+	//==============================================================
+
 }
 
 void Viewer::initBuffers(){
@@ -893,46 +1006,6 @@ void Viewer::initBuffers(){
 
 }
 
-void Viewer::drawTool() {
-    objShader->bind();
-
-    // Get projection and camera transformations
-    QMatrix4x4 modelViewMatrix;
-
-    //camera()->getModelViewMatrix(modelViewMatrix);
-
-    QMatrix4x4 toolboxPos = QMatrix4x4();
-    float swingMult = 1;
-    //scale.translate(QVector3D(0,1.5,0));
-    toolboxPos.translate(0.6, -0.25, -1.6);
-    toolboxPos.rotate(-100, 0, 1, 0);
-    if(swing.active) {
-        swingMult = 0.5 + 0.5 * cos(fmin(swing.length, frame - swing.startFrame) * 2 * M_PI / swing.length);
-        if(frame - swing.startFrame > swing.length) {
-            swing.active = false;
-        }
-    }
-    toolboxPos.rotate(swingMult * -65, 0, 0, 1);
-    toolboxPos.scale(0.06);
-
-    objShader->setUniformValue(o_u_mvMatrix, modelViewMatrix * toolboxPos);
-    objShader->setUniformValue(o_u_nmMatrix, modelViewMatrix.normalMatrix());
-
-    // Draw the meshes
-    for (unsigned int i=0; i<_meshesGL.size(); ++i)
-    {
-        // Set its material properties
-        objShader->setUniformValue(o_u_kd, _meshesGL[i].diffuse);
-        objShader->setUniformValue(o_u_ks, _meshesGL[i].specular);
-        objShader->setUniformValue(o_u_kn, _meshesGL[i].specularExponent);
-        objShader->setUniformValue(o_u_ka, _meshesGL[i].alpha);
-
-        // Draw the mesh
-        glBindVertexArray(_meshesGL[i].vao);
-        glDrawArrays(GL_TRIANGLES, 0, _meshesGL[i].numVertices);
-    }
-}
-
 void Viewer::visit(Cube &s)
 {
     m_program->bind();
@@ -1026,7 +1099,6 @@ void Viewer::visit(SceneGroup &s)
 	modelStack.pop();
 }
 
-
 void Viewer::setPhong(bool on) {
     m_program->bind();
     m_program->setUniformValue(m_isPhongLoc, on);

src/viewer/simpleViewer.h

@@ -89,6 +89,7 @@ signals:
 
 protected :
     virtual void draw();
+	virtual void drawParticles();
     virtual void drawSkybox();
     virtual void drawTool();
 	virtual void init();
@@ -184,8 +185,8 @@ private:
 	QColor* activeColor;
 	int activeShape;
 
-	enum VAO_IDs { VAO_Cube, VAO_Sphere, NumVAOs };
+	enum VAO_IDs { VAO_Cube, VAO_Sphere, VAO_Particle, NumVAOs };
-	enum Buffer_IDs { VBO_Cube, VBO_Sphere, EBO_Sphere, NumBuffers };
+	enum Buffer_IDs { VBO_Cube, VBO_Sphere, EBO_Sphere, VBO_Particle, VBO_Particle_Positions, VBO_Particle_Colors, NumBuffers };
 	enum RenderBuffer_IDs { RenderBuffer_Main, NumRenderBuffers };
 
 	GLuint m_VAOs[NumVAOs];