removed a single multiplication, minor comment changesHEADmaster

1 files changed, 15 insertions, 15 deletions

diff --git a/ball-sim.asm b/ball-sim.asm
index 769def2..567fbb7 100644
--- a/ball-sim.asm
+++ b/ball-sim.asm
@@ -99,20 +99,21 @@ no_click:
 	movaps xmm3, xmm2
 	movaps xmm4, xmm0
 
-	; dirty, rotten, low-down, no-good hack
-	cmpnleps xmm2, xmm1                 ; out of left/top bounds mask
-	cmpltps xmm0, xmm1                  ; out of right/bottom bounds mask
-	orps xmm0, xmm2                     ; or the masks
-	andps xmm0, [restitution_minus_one] ; mask & restitution coefficient minus one
-	addps xmm0, [ones]                  ; add ones to create bounce vector (0.0 -> 1.0, restitution - 1.0 -> restitution)
+	; dirty, rotten, low-down, no-good hack (bitmasks on floats and weird constants)
+	cmpnleps xmm2, xmm1
+	cmpltps xmm0, xmm1
+	orps xmm0, xmm2
+	andps xmm0, [restitution_coef]
+	addps xmm0, [air_resistance_coef]
+
+	; keep position in bounds
 	maxps xmm1, xmm3
-	minps xmm1, xmm4                    ; keep position in bounds
+	minps xmm1, xmm4
 
 	; scale velocity by bounce vector
 	mulps xmm0, [ball.vel]
 
-	; apply air resistance and gravity
-	mulps xmm0, [air_resistance_coef]
+	; apply gravity
 	addps xmm0, [grav_accel]
 
 	; store position
@@ -136,7 +137,7 @@ move_and_draw:
 	; sphere
 	movlps xmm0, [ball.pos]
 	movss xmm1, [ball.rad]
-	mov rdi, 0xFF2C7500 ; green
+	mov edi, 0xFF2C7500 ; green
 	call DrawCircleV
 
 	call EndDrawing
@@ -150,11 +151,10 @@ loop_entr:
 	call _exit
 
 section '.data' writable align 16
-	mouse_seek_speed      splat 0.5
-	minimum_radius        splat 2.5
-	air_resistance_coef   splat 0.99
-	restitution_minus_one splat -1.8
-	ones                  splat 1.0
+	mouse_seek_speed    splat 0.5
+	minimum_radius      splat 2.5
+	air_resistance_coef splat 0.99
+	restitution_coef    splat -1.782 ; -(restitution + 1) * air resistance
 
 	grav_accel Vec2 0.0, 0.69