[Bf-blender-cvs] [8008d9b] master: Fix T40078: GLSL Lamp with OnlyShadow makes weird colors in object.

[IRIE Shinsuke]

Commit: 8008d9bdfd5730b15727d0fb16f4417a4b8a85cc
Author: IRIE Shinsuke
Date:   Fri May 30 16:57:15 2014 +0900
https://developer.blender.org/rB8008d9bdfd5730b15727d0fb16f4417a4b8a85cc

Fix T40078: GLSL Lamp with OnlyShadow makes weird colors in object.

To prevent only shadow lamps from producing negative colors, shr->diff
and shr->spec should've been clamped to positive values after lamp loop.

===================================================================

M	source/blender/gpu/intern/gpu_material.c
M	source/blender/gpu/shaders/gpu_shader_material.glsl

===================================================================

diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index 5594c08..5ed47cd 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -765,20 +765,18 @@ static void shade_one_light(GPUShadeInput *shi, GPUShadeResult *shr, GPULamp *la
 			}
 			
 			if (lamp->mode & LA_ONLYSHADOW) {
-				GPUNodeLink *rgb;
+				GPUNodeLink *shadrgb;
 				GPU_link(mat, "shade_only_shadow", i, shadfac,
-					GPU_dynamic_uniform(&lamp->dynenergy, GPU_DYNAMIC_LAMP_DYNENERGY, lamp->ob), &shadfac);
-
-				GPU_link(mat, "shade_mul", shi->rgb, GPU_uniform(lamp->shadow_color), &rgb);
-				GPU_link(mat, "mtex_rgb_invert", rgb, &rgb);
+					GPU_dynamic_uniform(&lamp->dynenergy, GPU_DYNAMIC_LAMP_DYNENERGY, lamp->ob),
+					GPU_uniform(lamp->shadow_color), &shadrgb);
 				
 				if (!(lamp->mode & LA_NO_DIFF)) {
-					GPU_link(mat, "shade_only_shadow_diffuse", shadfac, rgb,
+					GPU_link(mat, "shade_only_shadow_diffuse", shadrgb, shi->rgb,
 						shr->diff, &shr->diff);
 				}
 
 				if (!(lamp->mode & LA_NO_SPEC))
-					GPU_link(mat, "shade_only_shadow_specular", shadfac, shi->specrgb,
+					GPU_link(mat, "shade_only_shadow_specular", shadrgb, shi->specrgb,
 						shr->spec, &shr->spec);
 				
 				add_user_list(&mat->lamps, lamp);
@@ -890,6 +888,10 @@ static void material_lights(GPUShadeInput *shi, GPUShadeResult *shr)
 			free_object_duplilist(lb);
 		}
 	}
+
+	/* prevent only shadow lamps from producing negative colors.*/
+	GPU_link(shi->gpumat, "shade_clamp_positive", shr->spec, &shr->spec);
+	GPU_link(shi->gpumat, "shade_clamp_positive", shr->diff, &shr->diff);
 }
 
 static void texture_rgb_blend(GPUMaterial *mat, GPUNodeLink *tex, GPUNodeLink *out, GPUNodeLink *fact, GPUNodeLink *facg, int blendtype, GPUNodeLink **in)
diff --git a/source/blender/gpu/shaders/gpu_shader_material.glsl b/source/blender/gpu/shaders/gpu_shader_material.glsl
index a224f8e..44119d4 100644
--- a/source/blender/gpu/shaders/gpu_shader_material.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_material.glsl
@@ -1921,19 +1921,24 @@ void ramp_rgbtobw(vec3 color, out float outval)
 	outval = color.r*0.3 + color.g*0.58 + color.b*0.12;
 }
 
-void shade_only_shadow(float i, float shadfac, float energy, out float outshadfac)
+void shade_only_shadow(float i, float shadfac, float energy, vec3 shadcol, out vec3 outshadrgb)
 {
-	outshadfac = i*energy*(1.0 - shadfac);
+	outshadrgb = i*energy*(1.0 - shadfac)*(vec3(1.0)-shadcol);
 }
 
-void shade_only_shadow_diffuse(float shadfac, vec3 rgb, vec4 diff, out vec4 outdiff)
+void shade_only_shadow_diffuse(vec3 shadrgb, vec3 rgb, vec4 diff, out vec4 outdiff)
 {
-	outdiff = diff - vec4(rgb*shadfac, 0.0);
+	outdiff = diff - vec4(rgb*shadrgb, 0.0);
 }
 
-void shade_only_shadow_specular(float shadfac, vec3 specrgb, vec4 spec, out vec4 outspec)
+void shade_only_shadow_specular(vec3 shadrgb, vec3 specrgb, vec4 spec, out vec4 outspec)
 {
-	outspec = spec - vec4(specrgb*shadfac, 0.0);
+	outspec = spec - vec4(specrgb*shadrgb, 0.0);
+}
+
+void shade_clamp_positive(vec4 col, out vec4 outcol)
+{
+	outcol = max(col, vec4(0.0));
 }
 
 void test_shadowbuf(vec3 rco, sampler2DShadow shadowmap, mat4 shadowpersmat, float shadowbias, float inp, out float result)