sokol: 3d pipelines for 3d layouts only

previous change was rushed, do not violate feierabend
for this.  node orientation is borked.

Author: qwx9

draw/drw.h

@@ -29,6 +29,7 @@ enum{
 	DFmsaa = 1<<5,
 	DFhidpi = 1<<6,
 	DFnope = 1<<7,
+	DF3d = 1<<8,
 };
 struct Drawing{
 	int flags;

glsl/node.glsl

@@ -15,23 +15,97 @@ in vec4 col;
 in float len;
 out vec4 c;
 
+vec2 rotatez(vec2 v, float c, float s){
+	return mat2(c, s, -s, c) * v;
+}
+
+void main(){
+	vec2 g = geom * vec2(len, 1.0);
+	vec3 r = vec3(rotatez(g, dir.x, dir.y), 0.0);
+	gl_Position = mvp * vec4(r + pos, 1.0);
+	c = col;
+}
+@end
+
+@fs fs
+precision mediump float;
+
+in vec4 c;
+out vec4 fc;
+
+void main(){
+	fc = c;
+}
+@end
+
+@vs vsoff
+@glsl_options fixup_clipspace
+
+precision mediump float;
+
+layout(binding=0) uniform Vparam {
+	mat4 mvp;
+};
+in vec2 geom;
+in vec3 pos;
+in vec3 dir;
+in float len;
+flat out uint idx;
+
+vec2 rotatez(vec2 v, float c, float s){
+	return mat2(c, s, -s, c) * v;
+}
+
+void main(){
+	vec2 g = geom * vec2(len, 1.0);
+	vec3 r = vec3(rotatez(g, dir.x, dir.y), 0.0);
+	gl_Position = mvp * vec4(r + pos, 1.0);
+	idx = gl_InstanceIndex + 1;
+}
+@end
+
+@fs fsoff
+precision mediump float;
+
+flat in uint idx;
+out uint fc;
+
+void main(){
+	fc = idx;
+}
+@end
+
+@vs vs3d
+@glsl_options fixup_clipspace
+
+precision mediump float;
+
+layout(binding=0) uniform Vparam {
+	mat4 mvp;
+};
+in vec3 geom;
+in vec3 pos;
+in vec3 dir;
+in vec4 col;
+in float len;
+out vec4 c;
+
 vec3 rotate(vec3 v, float c, float s){
-	float w = 1.0 - c;
 	return mat3(c, s, 0, -s, c, 0, 0, 0, 1)
 		* mat3(c, 0, s, 0, 1, 0, -s, 0, c)
 		* mat3(1, 0, 0, 0, c, s, 0, -s, c)
 		* v;
 }
 
 void main(){
-	vec3 g = vec3(geom * vec2(len, 1.0), 0.0);
+	vec3 g = geom * vec3(len, 1.0, 1.0);
 	vec3 r = rotate(g, dir.x, dir.y);
 	gl_Position = mvp * vec4(r + pos, 1.0);
 	c = col;
 }
 @end
 
-@fs fs
+@fs fs3d
 precision mediump float;
 
 in vec4 c;
@@ -42,37 +116,36 @@ void main(){
 }
 @end
 
-@vs vsoff
+@vs vsoff3d
 @glsl_options fixup_clipspace
 
 precision mediump float;
 
 layout(binding=0) uniform Vparam {
 	mat4 mvp;
 };
-in vec2 geom;
+in vec3 geom;
 in vec3 pos;
 in vec3 dir;
 in float len;
 flat out uint idx;
 
 vec3 rotate(vec3 v, float c, float s){
-	float w = 1.0 - c;
 	return mat3(c, s, 0, -s, c, 0, 0, 0, 1)
 		* mat3(c, 0, s, 0, 1, 0, -s, 0, c)
 		* mat3(1, 0, 0, 0, c, s, 0, -s, c)
 		* v;
 }
 
 void main(){
-	vec3 g = vec3(geom * vec2(len, 1.0), 0.0);
+	vec3 g = geom * vec3(len, 1.0, 1.0);
 	vec3 r = rotate(g, dir.x, dir.y);
 	gl_Position = mvp * vec4(r + pos, 1.0);
 	idx = gl_InstanceIndex + 1;
 }
 @end
 
-@fs fsoff
+@fs fsoff3d
 precision mediump float;
 
 flat in uint idx;
@@ -85,3 +158,5 @@ void main(){
 
 @program idx vsoff fsoff
 @program s vs fs
+@program idx3d vsoff3d fsoff3d
+@program s3d vs3d fs3d