From fcec771f34dee305d585d6ff8bc8e4e4e71ca377 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sat, 19 Aug 2023 16:19:11 +0900
Subject: [PATCH] internal/graphicscommand: clear uniform variables explicitly

This change is a performance optimization.

(*uint32sBuffer).alloc doesn't clear the uniform values. Without
clearing the values explicitly, CanMergeWithDrawTrianglesCommand
might return false even though two commands can be merged.
---
 internal/graphicscommand/command.go | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/internal/graphicscommand/command.go b/internal/graphicscommand/command.go
index 19b72b6b9..2a56fa4b1 100644
--- a/internal/graphicscommand/command.go
+++ b/internal/graphicscommand/command.go
@@ -675,21 +675,33 @@ func (q *commandQueue) prependPreservedUniforms(uniforms []uint32, shader *Shade
 		w, h := srcs[0].InternalSize()
 		uniforms[2] = math.Float32bits(float32(w))
 		uniforms[3] = math.Float32bits(float32(h))
+	} else {
+		uniforms[2] = 0
+		uniforms[3] = 0
 	}
 	if srcs[1] != nil {
 		w, h := srcs[1].InternalSize()
 		uniforms[4] = math.Float32bits(float32(w))
 		uniforms[5] = math.Float32bits(float32(h))
+	} else {
+		uniforms[4] = 0
+		uniforms[5] = 0
 	}
 	if srcs[2] != nil {
 		w, h := srcs[2].InternalSize()
 		uniforms[6] = math.Float32bits(float32(w))
 		uniforms[7] = math.Float32bits(float32(h))
+	} else {
+		uniforms[6] = 0
+		uniforms[7] = 0
 	}
 	if srcs[3] != nil {
 		w, h := srcs[3].InternalSize()
 		uniforms[8] = math.Float32bits(float32(w))
 		uniforms[9] = math.Float32bits(float32(h))
+	} else {
+		uniforms[8] = 0
+		uniforms[9] = 0
 	}
 
 	if shader.unit() == shaderir.Texels {