move shadows to a fullscreen buffer

2 files changed, 157 insertions, 50 deletions

diff --git a/intermediate/surface.glsl b/intermediate/surface.glsl
index 71a4307..82bf2f6 100644
--- a/intermediate/surface.glsl
+++ b/intermediate/surface.glsl
@@ -29,6 +29,9 @@ type: vec2
 name: uv
 type: vec2
 [interpolator]
+name: screen
+type: vec4
+[interpolator]
 name: position
 type: vec4
 [interpolator]
@@ -114,7 +117,7 @@ dimension: cube
 [texture]
 name: shadowmaps
 stage: fragment
-dimension: shadowArray
+dimension: array
 
 [target]
 name: colour
@@ -133,7 +136,9 @@ void main() {
 	interpolator.uv = uv;
 	interpolator.position = pos;
 	interpolator.tbn = mat3(t, b, n);
-	gl_Position = c_vp.view_projection * pos;
+	pos = c_vp.view_projection * pos;
+	interpolator.screen = pos;
+	gl_Position = pos;
 }
 
 #endif
@@ -170,54 +175,10 @@ float specular_brdf(vec2 uv, vec3 ref, vec3 l, vec3 v, vec3 n) {
 	return (D * F * G) / (4.0 * ndl * ndv + 0.001);
 }
 
-vec2 poissonDisk[16] = vec2[]( 
-	vec2(-0.94201624,  -0.39906216),
-	vec2(0.94558609,   -0.76890725),
-	vec2(-0.094184101, -0.92938870),
-	vec2(0.34495938,    0.29387760),
-	vec2(-0.91588581,   0.45771432),
-	vec2(-0.81544232,  -0.87912464),
-	vec2(-0.38277543,   0.27676845),
-	vec2(0.97484398,    0.75648379),
-	vec2(0.44323325,   -0.97511554),
-	vec2(0.53742981,   -0.47373420),
-	vec2(-0.26496911,  -0.41893023),
-	vec2(0.79197514,    0.19090188),
-	vec2(-0.24188840,   0.99706507),
-	vec2(-0.81409955,   0.91437590),
-	vec2(0.19984126,    0.78641367),
-	vec2(0.14383161,   -0.14100790)
-);
-
-float random(vec3 seed, int i){
-	vec4 seed4 = vec4(seed,i);
-	float dot_product = dot(seed4, vec4(12.9898,78.233,45.164,94.673));
-	return fract(sin(dot_product) * 43758.5453);
-}
-
-float get_shadow(Light l, vec3 wpos) {
-	const int taps = 4;
-	const float w = 1.0 / float(taps);
-	const float m = 1.0 / 1000.0;
-	int i;
-	float d = 0.0f;
-	Caster caster = casters[l.caster_id];
-	vec4 surf = caster.projection * vec4(wpos, 1.0);
-	surf /= surf.w;
-	surf.xy = surf.xy * 0.5 + 0.5;
-	surf.z -= 0.005;
-	for (i = 0; i < taps; i++) {
-		int index = int(16.0 * random(floor(wpos.xyz * 1000.0), i)) % 16;
-		vec2 coord = surf.xy + poissonDisk[index] * m;
-		vec4 vec = vec4(coord, float(l.caster_id), surf.z);
-		d += texture(shadowmaps, vec).r * w;
-	}
-	return d;
-}
-
 void main() {
 	int i;
 	vec2 uv = interpolator.uv;
+	vec2 suv = (interpolator.screen.xy / interpolator.screen.w) * 0.5 + 0.5;
 	vec3 p = interpolator.position.xyz;
 
 	vec3 nrmsample = texture(normal, uv).rgb;
@@ -251,9 +212,7 @@ void main() {
 			spec_col *
 			specular_brdf(uv, ref, light_dir, view_dir, nrm) *
 			cos_theta_i;
-		float shadow = 1.0f;
-		if (l.caster_id >= 0)
-			shadow = get_shadow(l, p);
+		float shadow = texture(shadowmaps, vec3(suv, float(l.caster_id))).r;
 		light += (diffuse + spec) * l.brightness * l.colour * shadow;
 	}
 
diff --git a/intermediate/ts.glsl b/intermediate/ts.glsl
new file mode 100644
index 0000000..23195f6
--- /dev/null
+++ b/intermediate/ts.glsl
@@ -0,0 +1,148 @@
+#ifdef DESC
+[program]
+type: graphics
+vertex: main
+fragment: main
+#endif
+
+#include "forward.h"
+
+#ifdef DESC
+
+[binding]
+name: verts
+rate: vertex
+[attribute]
+name: position
+type: vec2
+[attribute]
+name: uv
+type: vec2
+
+[interpolator]
+name: uv
+type: vec2
+
+[texture]
+name: shadowmaps
+stage: fragment
+dimension: shadowArray
+[texture]
+name: previous
+stage: fragment
+dimension: 2
+[texture]
+name: depthmap
+stage: fragment
+dimension: 2
+
+[struct]
+name: Config
+[variable]
+name: inv_view
+type: mat4
+[variable]
+name: inv_proj
+type: mat4
+[variable]
+name: prev_vp
+type: mat4
+
+[struct]
+name: Caster_Config
+[variable]
+name: index
+type: int
+
+[cbuffer]
+name: config
+type: Config
+stage: fragment
+
+[cbuffer]
+name: caster_config
+type: Caster_Config
+stage: fragment
+
+[sbuffer]
+name: casters
+type: Caster
+stage: fragment
+
+[target]
+name: shadow_amount
+type: float
+
+#endif
+
+#ifdef VERTEX_SHADER
+void main() {
+	interpolator.uv = uv;
+	gl_Position = vec4(position, 1.0, 1.0);
+}
+#endif
+
+#ifdef FRAGMENT_SHADER
+
+vec2 poissonDisk[16] = vec2[]( 
+	vec2(-0.94201624,  -0.39906216),
+	vec2(0.94558609,   -0.76890725),
+	vec2(-0.094184101, -0.92938870),
+	vec2(0.34495938,    0.29387760),
+	vec2(-0.91588581,   0.45771432),
+	vec2(-0.81544232,  -0.87912464),
+	vec2(-0.38277543,   0.27676845),
+	vec2(0.97484398,    0.75648379),
+	vec2(0.44323325,   -0.97511554),
+	vec2(0.53742981,   -0.47373420),
+	vec2(-0.26496911,  -0.41893023),
+	vec2(0.79197514,    0.19090188),
+	vec2(-0.24188840,   0.99706507),
+	vec2(-0.81409955,   0.91437590),
+	vec2(0.19984126,    0.78641367),
+	vec2(0.14383161,   -0.14100790)
+);
+
+float random(vec3 seed, int i){
+	vec4 seed4 = vec4(seed,i);
+	float dot_product = dot(seed4, vec4(12.9898,78.233,45.164,94.673));
+	return fract(sin(dot_product) * 43758.5453);
+}
+
+float get_shadow(int id, vec3 wpos) {
+	const int taps = 4;
+	const float w = 1.0 / float(taps);
+	const float m = 1.0 / 1000.0;
+	int i;
+	float d = 0.0f;
+	Caster caster = casters[id];
+	vec4 surf = caster.projection * vec4(wpos, 1.0);
+	surf /= surf.w;
+	surf.xy = surf.xy * 0.5 + 0.5;
+	surf.z -= 0.005;
+	for (i = 0; i < taps; i++) {
+		int index = int(16.0 * random(floor(wpos.xyz * 1000.0), i + globals.frame)) % 16;
+		vec2 coord = surf.xy + poissonDisk[index] * m;
+		vec4 vec = vec4(coord, float(id), surf.z);
+		d += texture(shadowmaps, vec).r * w;
+	}
+	return d;
+}
+
+vec3 get_world_pos(float depth, vec2 uv) {
+	float z = depth;
+	vec4 clip = vec4(uv * 2.0 - 1.0, z, 1.0);
+	vec4 view = config.inv_proj * clip;
+	view /= view.w;
+	return (config.inv_view * view).xyz;
+}
+
+void main() {
+	vec2 uv = interpolator.uv;
+	float d = texture(depthmap, uv).r;
+	vec3 wpos = get_world_pos(d, uv);
+	float prev = texture(previous, uv).r;
+	float current = get_shadow(caster_config.index, wpos);
+	shadow_amount = (prev + current) * 0.5;
+}
+#endif