From: vortex <vortex@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Sat, 19 Mar 2011 20:26:54 +0000 (+0000)
Subject: Add "Both Alphas" technique for VertexTextureBlend (use both layer alpha's for microb... 
X-Git-Tag: xonotic-v0.6.0~163^2~609
X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=129b7033f5fc1864d34031fcb35044409587a24f;p=xonotic%2Fdarkplaces.git

Add "Both Alphas" technique for VertexTextureBlend (use both layer alpha's for microblending), toggled globally by "r_glsl_vertextextureblend_usebothalphas" cvar.

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@10937 d7cf8633-e32d-0410-b094-e92efae38249
---

diff --git a/gl_rmain.c b/gl_rmain.c
index a2ab80ea..2cc3d857 100644
--- a/gl_rmain.c
+++ b/gl_rmain.c
@@ -206,6 +206,8 @@ cvar_t r_overheadsprites_scaley = {CVAR_SAVE, "r_overheadsprites_scaley", "1", "
 cvar_t r_glsl_saturation = {CVAR_SAVE, "r_glsl_saturation", "1", "saturation multiplier (only working in glsl!)"};
 cvar_t r_glsl_saturation_redcompensate = {CVAR_SAVE, "r_glsl_saturation_redcompensate", "0", "a 'vampire sight' addition to desaturation effect, does compensation for red color, r_glsl_restart is required"};
 
+cvar_t r_glsl_vertextextureblend_usebothalphas = {CVAR_SAVE, "r_glsl_vertextextureblend_usebothalphas", "0", "use both alpha layers on vertex blended surfaces, each alpha layer sets amount of 'blend leak' on another layer."};
+
 cvar_t r_framedatasize = {CVAR_SAVE, "r_framedatasize", "0.5", "size of renderer data cache used during one frame (for skeletal animation caching, light processing, etc)"};
 
 extern cvar_t v_glslgamma;
@@ -844,7 +846,8 @@ enum
 	SHADERSTATICPARM_POSTPROCESS_USERVEC1 = 2, ///< postprocess uservec1 is enabled
 	SHADERSTATICPARM_POSTPROCESS_USERVEC2 = 3, ///< postprocess uservec2 is enabled
 	SHADERSTATICPARM_POSTPROCESS_USERVEC3 = 4, ///< postprocess uservec3 is enabled
-	SHADERSTATICPARM_POSTPROCESS_USERVEC4 = 5  ///< postprocess uservec4 is enabled
+	SHADERSTATICPARM_POSTPROCESS_USERVEC4 = 5,  ///< postprocess uservec4 is enabled
+	SHADERSTATICPARM_VERTEXTEXTUREBLEND_USEBOTHALPHAS = 6 // use both alpha layers while blending materials, allows more advanced microblending
 };
 #define SHADERSTATICPARMS_COUNT 6
 
@@ -862,6 +865,8 @@ qboolean R_CompileShader_CheckStaticParms(void)
 	// detect all
 	if (r_glsl_saturation_redcompensate.integer)
 		R_COMPILESHADER_STATICPARM_ENABLE(SHADERSTATICPARM_SATURATION_REDCOMPENSATE);
+	if (r_glsl_vertextextureblend_usebothalphas.integer)
+		R_COMPILESHADER_STATICPARM_ENABLE(SHADERSTATICPARM_VERTEXTEXTUREBLEND_USEBOTHALPHAS);
 	if (r_shadow_glossexact.integer)
 		R_COMPILESHADER_STATICPARM_ENABLE(SHADERSTATICPARM_EXACTSPECULARMATH);
 	if (r_glsl_postprocess.integer)
@@ -894,6 +899,7 @@ void R_CompileShader_AddStaticParms(unsigned int mode, unsigned int permutation)
 	R_COMPILESHADER_STATICPARM_EMIT(SHADERSTATICPARM_POSTPROCESS_USERVEC2, "USERVEC2");
 	R_COMPILESHADER_STATICPARM_EMIT(SHADERSTATICPARM_POSTPROCESS_USERVEC3, "USERVEC3");
 	R_COMPILESHADER_STATICPARM_EMIT(SHADERSTATICPARM_POSTPROCESS_USERVEC4, "USERVEC4");
+	R_COMPILESHADER_STATICPARM_EMIT(SHADERSTATICPARM_VERTEXTEXTUREBLEND_USEBOTHALPHAS, "USEBOTHALPHAS");
 }
 
 /// information about each possible shader permutation
@@ -4133,6 +4139,7 @@ void GL_Main_Init(void)
 	Cvar_RegisterVariable(&r_test);
 	Cvar_RegisterVariable(&r_glsl_saturation);
 	Cvar_RegisterVariable(&r_glsl_saturation_redcompensate);
+	Cvar_RegisterVariable(&r_glsl_vertextextureblend_usebothalphas);
 	Cvar_RegisterVariable(&r_framedatasize);
 	if (gamemode == GAME_NEHAHRA || gamemode == GAME_TENEBRAE)
 		Cvar_SetValue("r_fullbrights", 0);
diff --git a/shader_glsl.h b/shader_glsl.h
index 515556ae..955d49e2 100644
--- a/shader_glsl.h
+++ b/shader_glsl.h
@@ -1087,10 +1087,16 @@
 "	color.rgb += myhalf3(offsetMappedTexture2D(Texture_Pants)) * Color_Pants + myhalf3(offsetMappedTexture2D(Texture_Shirt)) * Color_Shirt;\n"
 "#endif\n"
 "#ifdef USEVERTEXTEXTUREBLEND\n"
+"#ifdef USEBOTHALPHAS\n"
+"	myhalf4 color2 = myhalf4(dp_texture2D(Texture_SecondaryColor, TexCoord2));\n"
+"	myhalf terrainblend = clamp(myhalf(VertexColor.a) * color.a, myhalf(1.0 - color2.a), myhalf(1.0));\n"
+"	color.rgb = mix(color2.rgb, color.rgb, terrainblend);\n"
+"#else\n"
 "	myhalf terrainblend = clamp(myhalf(VertexColor.a) * color.a * 2.0 - 0.5, myhalf(0.0), myhalf(1.0));\n"
 "	//myhalf terrainblend = min(myhalf(VertexColor.a) * color.a * 2.0, myhalf(1.0));\n"
 "	//myhalf terrainblend = myhalf(VertexColor.a) * color.a > 0.5;\n"
 "	color.rgb = mix(myhalf3(dp_texture2D(Texture_SecondaryColor, TexCoord2)), color.rgb, terrainblend);\n"
+"#endif\n"
 "	color.a = 1.0;\n"
 "	//color = mix(myhalf4(1, 0, 0, 1), color, terrainblend);\n"
 "#endif\n"
diff --git a/shader_hlsl.h b/shader_hlsl.h
index f5d1dd8a..67824e75 100644
--- a/shader_hlsl.h
+++ b/shader_hlsl.h
@@ -1250,6 +1250,11 @@
 "	color.rgb += half3(offsetMappedTexture2D(Texture_Pants).rgb) * Color_Pants + half3(offsetMappedTexture2D(Texture_Shirt).rgb) * Color_Shirt;\n"
 "#endif\n"
 "#ifdef USEVERTEXTEXTUREBLEND\n"
+"#ifdef USEBOTHALPHAS\n"
+"	half4 color2 = half4(tex2D(Texture_SecondaryColor, TexCoord2));\n"
+"	half terrainblend = clamp(half(gl_FrontColor.a) * color.a, half(1.0 - color2.a), half(1.0));\n"
+"	color.rgb = lerp(color2.rgb, color.rgb, terrainblend);\n"
+"#else\n"
 "	half terrainblend = clamp(half(gl_FrontColor.a) * color.a * 2.0 - 0.5, half(0.0), half(1.0));\n"
 "	//half terrainblend = min(half(gl_FrontColor.a) * color.a * 2.0, half(1.0));\n"
 "	//half terrainblend = half(gl_FrontColor.a) * color.a > 0.5;\n"
@@ -1257,6 +1262,7 @@
 "	color.a = 1.0;\n"
 "	//color = half4(lerp(float4(1, 0, 0, 1), color, terrainblend));\n"
 "#endif\n"
+"#endif\n"
 "\n"
 "	// get the surface normal\n"
 "#ifdef USEVERTEXTEXTUREBLEND\n"