From 947f55f10b157efa5ca1fe2189d21b3e5adddc09 Mon Sep 17 00:00:00 2001
From: fgenesis <false.genesis@googlemail.com>
Date: Wed, 5 Feb 2025 05:30:46 +0100
Subject: [PATCH] simplify particle render

Less special cases for non-rotated and non-flipped particles,
but since these are rare and the rest of the quad rendering code
has already gotten improvements there's not really any reason to keep
the specialized modes around.
The gains in GL calls were negligible and the new quad render code avoids
glVertex3f() entirely, which is a much better gain imho.
---
 BBGE/Emitter.cpp         | 118 +++++++--------------------------------
 BBGE/ParticleManager.cpp |   2 -
 BBGE/Particles.h         |   1 -
 3 files changed, 21 insertions(+), 100 deletions(-)

diff --git a/BBGE/Emitter.cpp b/BBGE/Emitter.cpp
index 375d0ba..32d0d19 100644
--- a/BBGE/Emitter.cpp
+++ b/BBGE/Emitter.cpp
@@ -64,7 +64,6 @@ Emitter::Emitter(ParticleEffect *pe) : Quad(), pe(pe)
 {
 	//HACK:
 	cull = false;
-	hasRot = false;
 }
 
 void Emitter::destroy()
@@ -250,115 +249,40 @@ void Emitter::onRender(const RenderState& rs) const
 		core->setupRenderPositionAndScale();
 	}
 
-	float w2 = width*0.5f;
-	float h2 = height*0.5f;
-
 	if (texture)
 		texture->apply();
 
+	Vector colorMult = rs.color;
+	if(data.inheritColor)
+		colorMult *= pe->color;
+	float alphaMult = rs.alpha;
+	if(data.inheritAlpha)
+		alphaMult *= pe->alpha.x;
 
+	const RenderGrid * const rquad = core->getDefaultQuadGrid();
 	const bool flip = data.flipH != (data.copyParentFlip && pe->isfhr());
-	if (flip || hasRot)
+
+	for (Particles::const_iterator i = particles.begin(); i != particles.end(); i++)
 	{
-		Vector colorMult = data.inheritColor ? pe->color : Vector(1, 1, 1);
-		float alphaMult = data.inheritAlpha ? pe->alpha.x : 1;
-
-		for (Particles::const_iterator i = particles.begin(); i != particles.end(); i++)
+		Particle *p = *i;
+		if (p->active)
 		{
-			Particle *p = *i;
-			if (p->active)
-			{
-				const float dx = w2 * p->scale.x;
-				const float dy = h2 * p->scale.y;
+			const Vector col = p->color * colorMult;
+			glColor4f(col.x, col.y, col.z, p->alpha.x * alphaMult);
 
-				Vector col = p->color * colorMult;
-				glColor4f(col.x, col.y, col.z, p->alpha.x * alphaMult);
+			glPushMatrix();
 
+				glTranslatef(p->pos.x, p->pos.y,0);
+				glScalef(width * p->scale.x, height * p->scale.y, 0);
 
-				if (flip || p->rot.z != 0 || p->rot.isInterpolating())
-				{
-					glPushMatrix();
+				glRotatef(p->rot.z, 0, 0, 1);
 
-						glTranslatef(p->pos.x, p->pos.y,0);
+				if (flip)
+					glRotatef(180, 0, 1, 0);
 
-						glRotatef(p->rot.z, 0, 0, 1);
+				rquad->render(rs);
 
-						if (flip)
-						{
-							glRotatef(180, 0, 1, 0);
-						}
-
-
-
-						glBegin(GL_QUADS);
-							glTexCoord2f(0,1);
-							glVertex2f(-dx, +dy);
-
-							glTexCoord2f(1,1);
-							glVertex2f(+dx, +dy);
-
-							glTexCoord2f(1,0);
-							glVertex2f(+dx, -dy);
-
-							glTexCoord2f(0,0);
-							glVertex2f(-dx, -dy);
-						glEnd();
-
-					glPopMatrix();
-				}
-				else
-				{
-					const float x = p->pos.x;
-					const float y = p->pos.y;
-
-					glBegin(GL_QUADS);
-						glTexCoord2f(0,1);
-						glVertex2f(x-dx, y+dy);
-
-						glTexCoord2f(1,1);
-						glVertex2f(x+dx, y+dy);
-
-						glTexCoord2f(1,0);
-						glVertex2f(x+dx, y-dy);
-
-						glTexCoord2f(0,0);
-						glVertex2f(x-dx, y-dy);
-					glEnd();
-				}
-			}
+			glPopMatrix();
 		}
 	}
-	else
-	{
-		glBegin(GL_QUADS);
-		for (Particles::const_iterator i = particles.begin(); i != particles.end(); i++)
-		{
-			Particle *p = *i;
-			if (p->active)
-			{
-				const float x = p->pos.x;
-				const float y = p->pos.y;
-				const float dx = w2 * p->scale.x;
-				const float dy = h2 * p->scale.y;
-
-				glColor4f(p->color.x, p->color.y, p->color.z, p->alpha.x);
-
-				glTexCoord2f(0,1);
-				glVertex2f(x-dx, y+dy);
-
-				glTexCoord2f(1,1);
-				glVertex2f(x+dx, y+dy);
-
-				glTexCoord2f(1,0);
-				glVertex2f(x+dx, y-dy);
-
-				glTexCoord2f(0,0);
-				glVertex2f(x-dx, y-dy);
-			}
-		}
-		glEnd();
-	}
-
-
-
 }
diff --git a/BBGE/ParticleManager.cpp b/BBGE/ParticleManager.cpp
index 15db284..a28cd56 100644
--- a/BBGE/ParticleManager.cpp
+++ b/BBGE/ParticleManager.cpp
@@ -146,8 +146,6 @@ void ParticleManager::updateParticle(Particle *p, float dt)
 				p->vel += dir * dt;
 			}
 		}
-		if (p->rot.z != 0 || p->rot.isInterpolating())
-			p->emitter->hasRot = true;
 	}
 
 	if (p->life <= 0)
diff --git a/BBGE/Particles.h b/BBGE/Particles.h
index 69215ae..a7248ee 100644
--- a/BBGE/Particles.h
+++ b/BBGE/Particles.h
@@ -116,7 +116,6 @@ public:
 
 	Vector getSpawnPosition();
 
-	bool hasRot; // FIXME: this should be removed eventually
 protected:
 	Vector lastSpawn;
 	float lastDTDifference;