From ba3be9affd51b7a58de1da67e546e70fff484dc3 Mon Sep 17 00:00:00 2001
From: kingscallop <54776947+kingscallop@users.noreply.github.com>
Date: Sun, 16 Aug 2020 19:44:00 +0100
Subject: [PATCH] Fixes example 42 (#2235)

Because example 42 was using the shaders from example 07 (callback), which have
input vertex attributes position and color, while the mesh from example 42 has
attributes position and normal, this causes problems on Windows when using
AMD gpus (no bunny mesh would appear on the window).
---
 examples/42-bunnylod/bunnylod.cpp   |  2 +-
 examples/42-bunnylod/fs_bunnylod.sc | 17 +++++++++++++++++
 examples/42-bunnylod/makefile       | 10 ++++++++++
 examples/42-bunnylod/varying.def.sc |  5 +++++
 examples/42-bunnylod/vs_bunnylod.sc | 16 ++++++++++++++++
 5 files changed, 49 insertions(+), 1 deletion(-)
 create mode 100644 examples/42-bunnylod/fs_bunnylod.sc
 create mode 100644 examples/42-bunnylod/makefile
 create mode 100644 examples/42-bunnylod/varying.def.sc
 create mode 100644 examples/42-bunnylod/vs_bunnylod.sc

diff --git a/examples/42-bunnylod/bunnylod.cpp b/examples/42-bunnylod/bunnylod.cpp
index 527beaa38..47fe4f2b9 100644
--- a/examples/42-bunnylod/bunnylod.cpp
+++ b/examples/42-bunnylod/bunnylod.cpp
@@ -265,7 +265,7 @@ public:
 		u_tint = bgfx::createUniform("u_tint", bgfx::UniformType::Vec4);
 
 		// Create program from shaders.
-		m_program = loadProgram("vs_callback", "fs_callback");
+		m_program = loadProgram("vs_bunnylod", "fs_bunnylod");
 
 		Mesh* mesh = meshLoad("meshes/bunny_patched.bin", true);
 		loadMesh(mesh);
diff --git a/examples/42-bunnylod/fs_bunnylod.sc b/examples/42-bunnylod/fs_bunnylod.sc
new file mode 100644
index 000000000..5ccdc6e1d
--- /dev/null
+++ b/examples/42-bunnylod/fs_bunnylod.sc
@@ -0,0 +1,17 @@
+$input v_world, v_color0
+
+/*
+ * Copyright 2011-2020 Branimir Karadzic. All rights reserved.
+ * License: https://github.com/bkaradzic/bgfx#license-bsd-2-clause
+ */
+
+#include "../common/common.sh"
+
+void main()
+{
+	vec3 normal = normalize(cross(dFdx(v_world), dFdy(v_world) ) );
+	vec3 lightDir = vec3(0.0, 0.0, 1.0);
+	float ndotl = max(dot(normal, lightDir), 0.0);
+	float spec = pow(ndotl, 30.0);
+	gl_FragColor = pow(pow(v_color0, vec4_splat(2.2) ) * ndotl + spec, vec4_splat(1.0/2.2) );
+}
diff --git a/examples/42-bunnylod/makefile b/examples/42-bunnylod/makefile
new file mode 100644
index 000000000..5c49b1667
--- /dev/null
+++ b/examples/42-bunnylod/makefile
@@ -0,0 +1,10 @@
+#
+# Copyright 2011-2020 Branimir Karadzic. All rights reserved.
+# License: https://github.com/bkaradzic/bgfx#license-bsd-2-clause
+#
+
+BGFX_DIR=../..
+RUNTIME_DIR=$(BGFX_DIR)/examples/runtime
+BUILD_DIR=../../.build
+
+include $(BGFX_DIR)/scripts/shader.mk
diff --git a/examples/42-bunnylod/varying.def.sc b/examples/42-bunnylod/varying.def.sc
new file mode 100644
index 000000000..bdc7f97fc
--- /dev/null
+++ b/examples/42-bunnylod/varying.def.sc
@@ -0,0 +1,5 @@
+vec3 v_world     : TEXCOORD0 = vec3(0.0, 0.0, 0.0);
+vec4 v_color0    : COLOR0    = vec4(1.0, 0.0, 0.0, 1.0);
+
+vec3 a_position  : POSITION;
+vec3 a_normal    : NORMAL;
diff --git a/examples/42-bunnylod/vs_bunnylod.sc b/examples/42-bunnylod/vs_bunnylod.sc
new file mode 100644
index 000000000..4df11502b
--- /dev/null
+++ b/examples/42-bunnylod/vs_bunnylod.sc
@@ -0,0 +1,16 @@
+$input a_position, a_normal
+$output v_world, v_color0
+
+/*
+ * Copyright 2011-2020 Branimir Karadzic. All rights reserved.
+ * License: https://github.com/bkaradzic/bgfx#license-bsd-2-clause
+ */
+
+#include "../common/common.sh"
+
+void main()
+{
+	gl_Position = mul(u_modelViewProj, vec4(a_position, 1.0) );
+	v_world = mul(u_model[0], vec4(a_position, 1.0) ).xyz;
+	v_color0 = vec4(a_normal, 1.0);
+}