particle VBOs

1 files changed, 50 insertions, 15 deletions

diff --git a/src/particle.cpp b/src/particle.cpp
index 8090e2d..3e140ae 100644
--- a/src/particle.cpp
+++ b/src/particle.cpp
@@ -12,9 +12,9 @@ ParticleSystem::ParticleSystem(int count, bool m)
 
 void ParticleSystem::add(const vec2& pos, const ParticleType& type)
 {
-	// TODO enforce max
-	//if (max && parts.size() >= std::end(parts))
-	//	return;
+	// TODO not enforce max
+	if (/*max &&*/ parts.size() + 1 >= parts.capacity())
+		return;
 
 	parts.emplace_back(pos, type);
 }
@@ -28,16 +28,32 @@ void ParticleSystem::addMultiple(const int& count, const ParticleType& type, std
 
 void ParticleSystem::render(void) const
 {
-	static const GLfloat tex[12] = {
-		0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0
-	};
+	static GLuint particleVBO = 9999, texVBO = 0;
+
+	if (particleVBO == 9999) {
+		glGenBuffers(1, &particleVBO);
+		glBindBuffer(GL_ARRAY_BUFFER, particleVBO);
+		glBufferData(GL_ARRAY_BUFFER, parts.capacity() * 18 * sizeof(GLfloat), nullptr,
+			GL_STREAM_DRAW);
+
+		glGenBuffers(1, &texVBO);
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, texVBO);
+		glBufferData(GL_ELEMENT_ARRAY_BUFFER, parts.capacity() * 12 * sizeof(GLfloat), nullptr,
+			GL_STATIC_DRAW);
+		int top = (parts.capacity() - 1) * 12 * sizeof(GLfloat), i = 0;
+		unsigned char zero = 0;
+		while (i < top) {
+			glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, i, 1, &zero);
+			i++;
+		}
+	}
 
-	Render::worldShader.use();
-	Render::worldShader.enable();
-	Colors::blue.use();
+	glBindBuffer(GL_ARRAY_BUFFER, particleVBO);
 
+	// copy data into VBO
+	int offset = 0;
 	for (const auto& p : parts) {
-		GLfloat coord[18] = {
+		GLfloat coords[18] = {
 			p.location.x, p.location.y, -1,
 			p.location.x, p.location.y + 5, -1,
 			p.location.x + 5, p.location.y + 5, -1,
@@ -45,14 +61,33 @@ void ParticleSystem::render(void) const
 			p.location.x + 5, p.location.y, -1,
 			p.location.x, p.location.y, -1
 		};
-
-		glVertexAttribPointer(Render::worldShader.coord, 3, GL_FLOAT, GL_FALSE, 0, coord);
-		glVertexAttribPointer(Render::worldShader.tex, 2, GL_FLOAT, GL_FALSE, 0, tex);
-		glDrawArrays(GL_TRIANGLES, 0, 6);
+		
+		glBufferSubData(GL_ARRAY_BUFFER, offset, 18 * sizeof(GLfloat), coords);
+		offset += 18 * sizeof(GLfloat);
 	}
+	
+	Render::worldShader.use();
+	Render::worldShader.enable();
+	Colors::blue.use();
+	//glUniform4f(Render::worldShader.uniform[WU_tex_color], 0.0f, 0.0f, 1.0f, 1.0f);
+
+	glEnableClientState(GL_VERTEX_ARRAY);
+
+	glBindBuffer(GL_ARRAY_BUFFER, particleVBO);
+	glVertexAttribPointer(Render::worldShader.coord, 3, GL_FLOAT, GL_FALSE, 0, 0);
+
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, texVBO);
+	glVertexAttribPointer(Render::worldShader.tex, 2, GL_FLOAT, GL_FALSE, 0, 0);
+
+	glDrawArrays(GL_TRIANGLES, 0, parts.size() * 6);
+
+	glDisableClientState(GL_VERTEX_ARRAY);
 
 	Render::worldShader.disable();
 	Render::worldShader.unuse();
+
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 }
 
 void ParticleSystem::update(entityx::EntityManager &en, entityx::EventManager &ev, entityx::TimeDelta dt)
@@ -74,7 +109,7 @@ void ParticleSystem::update(entityx::EntityManager &en, entityx::EventManager &e
 		// update movement
 		switch (p.type) {
 		case ParticleType::Drop:
-			if (p.velocity.y > -.5)
+			if (p.velocity.y > -.6)
 				p.velocity.y -= 0.001f;
 			break;
 		case ParticleType::Confetti: