[PATCH 4/6] wined3d: Fix specular lighting for non-local viewer.

[Matteo Bruni]

The viewer is in the (0.0, 0.0, -1.0) direction in the D3D coordinate
system.
---
 dlls/wined3d/glsl_shader.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/dlls/wined3d/glsl_shader.c b/dlls/wined3d/glsl_shader.c
index 0b239af..c40d42b 100644
--- a/dlls/wined3d/glsl_shader.c
+++ b/dlls/wined3d/glsl_shader.c
@@ -5267,7 +5267,7 @@ static void shader_glsl_ffp_vertex_lighting(struct wined3d_shader_buffer *buffer
                 if (settings->localviewer)
                     shader_addline(buffer, "t = dot(normal, normalize(dir - normalize(ec_pos.xyz)));\n");
                 else
-                    shader_addline(buffer, "t = dot(normal, normalize(dir + vec3(0.0, 0.0, 1.0)));\n");
+                    shader_addline(buffer, "t = dot(normal, normalize(dir + vec3(0.0, 0.0, -1.0)));\n");
                 shader_addline(buffer, "if (t > 0.0) specular += (pow(t, gl_FrontMaterial.shininess)"
                         " * gl_LightSource[%u].specular) / att;\n", i);
                 break;
@@ -5292,7 +5292,7 @@ static void shader_glsl_ffp_vertex_lighting(struct wined3d_shader_buffer *buffer
                 if (settings->localviewer)
                     shader_addline(buffer, "t = dot(normal, normalize(dir - normalize(ec_pos.xyz)));\n");
                 else
-                    shader_addline(buffer, "t = dot(normal, normalize(dir + vec3(0.0, 0.0, 1.0)));\n");
+                    shader_addline(buffer, "t = dot(normal, normalize(dir + vec3(0.0, 0.0, -1.0)));\n");
                 shader_addline(buffer, "if (t > 0.0) specular += (pow(t, gl_FrontMaterial.shininess)"
                         " * gl_LightSource[%u].specular) * att;\n", i);
                 break;
@@ -5304,7 +5304,12 @@ static void shader_glsl_ffp_vertex_lighting(struct wined3d_shader_buffer *buffer
                 shader_addline(buffer, "dir = normalize(gl_LightSource[%u].position.xyz);\n", i);
                 shader_addline(buffer, "diffuse += clamp(dot(dir, normal), 0.0, 1.0)"
                         " * gl_LightSource[%u].diffuse.xyz;\n", i);
-                shader_addline(buffer, "t = dot(normal, gl_LightSource[%u].halfVector.xyz);\n", i);
+                /* TODO: In the non-local viewer case the halfvector is constant
+                 * and could be precomputed and stored in a uniform. */
+                if (settings->localviewer)
+                    shader_addline(buffer, "t = dot(normal, normalize(dir - normalize(ec_pos.xyz)));\n");
+                else
+                    shader_addline(buffer, "t = dot(normal, normalize(dir + vec3(0.0, 0.0, -1.0)));\n");
                 shader_addline(buffer, "if (t > 0.0) specular += pow(t, gl_FrontMaterial.shininess)"
                         " * gl_LightSource[%u].specular;\n", i);
                 break;
-- 
2.0.5