Create and load the id sky shader.

libs/video/renderer/glsl/Makefile.am

@@ -5,10 +5,11 @@ INCLUDES= -I$(top_srcdir)/include $(GLX_CFLAGS)
 
 shader_src= \
 	quake2d.frag quakebsp.frag quakebsp.vert quakeico.vert quakemdl.frag \
-	quakemdl.vert quakespr.frag quakespr.vert quaketrb.frag quaketxt.vert
+	quakemdl.vert quakeski.frag quakesky.vert quakespr.frag quakespr.vert \
+	quaketrb.frag quaketxt.vert
 shader_gen= \
 	quake2d.fc quakebsp.fc quakebsp.vc quakeico.vc quakemdl.fc quakemdl.vc \
-	quakespr.fc quakespr.vc quaketrb.fc quaketxt.vc
+	quakeski.fc quakesky.vc quakespr.fc quakespr.vc quaketrb.fc quaketxt.vc
 
 glsl_src = \
 	glsl_alias.c glsl_bsp.c glsl_draw.c glsl_lightmap.c glsl_main.c \

libs/video/renderer/glsl/glsl_bsp.c

@@ -104,6 +104,14 @@ static const char quaketurb_frag[] =
 #include "quaketrb.fc"
 ;
 
+static const char quakesky_vert[] =
+#include "quakesky.vc"
+;
+
+static const char quakeskyid_frag[] =
+#include "quakeski.fc"
+;
+
 static struct {
 	int         program;
 	shaderparam_t mvp_matrix;
@@ -142,6 +150,26 @@ static struct {
 	{"realtime", 1},
 };
 
+static struct {
+	int         program;
+	shaderparam_t mvp_matrix;
+	shaderparam_t sky_matrix;
+	shaderparam_t vertex;
+	shaderparam_t palette;
+	shaderparam_t solid;
+	shaderparam_t trans;
+	shaderparam_t realtime;
+} quake_skyid = {
+	0,
+	{"mvp_mat", 1},
+	{"sky_mat", 1},
+	{"vertex", 0},
+	{"palette", 1},
+	{"solid", 1},
+	{"trans", 1},
+	{"realtime", 1},
+};
+
 #define CHAIN_SURF_F2B(surf,chain)							\
 	do { 													\
 		instsurf_t *inst = (surf)->instsurf;				\
@@ -961,4 +989,16 @@ R_InitBsp (void)
 	GL_ResolveShaderParam (quake_turb.program, &quake_turb.palette);
 	GL_ResolveShaderParam (quake_turb.program, &quake_turb.texture);
 	GL_ResolveShaderParam (quake_turb.program, &quake_turb.realtime);
+
+	vert = GL_CompileShader ("quakesky.vert", quakesky_vert, GL_VERTEX_SHADER);
+	frag = GL_CompileShader ("quakeski.frag", quakeskyid_frag,
+							 GL_FRAGMENT_SHADER);
+	quake_skyid.program = GL_LinkProgram ("quakebsp", vert, frag);
+	GL_ResolveShaderParam (quake_skyid.program, &quake_skyid.mvp_matrix);
+	GL_ResolveShaderParam (quake_skyid.program, &quake_skyid.sky_matrix);
+	GL_ResolveShaderParam (quake_skyid.program, &quake_skyid.vertex);
+	GL_ResolveShaderParam (quake_skyid.program, &quake_skyid.palette);
+	GL_ResolveShaderParam (quake_skyid.program, &quake_skyid.solid);
+	GL_ResolveShaderParam (quake_skyid.program, &quake_skyid.trans);
+	GL_ResolveShaderParam (quake_skyid.program, &quake_skyid.realtime);
 }

libs/video/renderer/glsl/quakeski.frag

@@ -0,0 +1,28 @@
+uniform sampler2D palette;
+uniform sampler2D solid;
+uniform sampler2D trans;
+uniform float realtime;
+
+varying vec3 direction;
+
+const float SCALE = 189.0 / 64.0;
+
+void
+main (void)
+{
+	float       len;
+	float       pix;
+	vec2        flow = vec2 (1.0, 1.0);
+	vec2        st;
+
+	len = dot (direction, direction);
+	len = SCALE * inversesqrt (len);
+
+	st = direction.xy * len + flow * realtime / 8.0;
+	pix = texture2D (trans, st).r;
+	if (pix == 1.0) {
+		st = direction.xy * len + flow * realtime / 8.0;
+		pix = texture2D (solid, st).r;
+	}
+	gl_FragColor = texture2D (palette, vec2 (pix, 0.5));
+}

libs/video/renderer/glsl/quakesky.vert

@@ -0,0 +1,17 @@
+uniform mat4 mvp_mat;
+uniform mat4 sky_mat;
+
+attribute vec4 vertex;
+
+varying vec3 direction;
+
+void
+main (void)
+{
+	vec3        dir;
+	float       len;
+	vec2        offset = vec2 (1.0, 1.0);
+
+	gl_Position = mvp_mat * vertex;
+	direction = (sky_mat * vertex).xyz;
+}