Initial cut of shadow map creation with support for billboard shadows

5 files changed, 93 insertions, 1 deletions

diff --git a/gfx/gl/shaders/shadowDynamicPointStencil.fs b/gfx/gl/shaders/shadowDynamicPointStencil.fs
new file mode 100644
index 0000000..57b8aa3
--- /dev/null
+++ b/gfx/gl/shaders/shadowDynamicPointStencil.fs
@@ -0,0 +1,16 @@
+#version 330 core
+#extension GL_ARB_shading_language_420pack : enable
+
+layout(binding = 0) uniform sampler2D stencilDepth;
+flat in vec3 scale;
+in vec2 texCoord;
+
+void
+main()
+{
+	float stDepth = texture(stencilDepth, texCoord).r;
+	if (stDepth >= 1) {
+		discard;
+	}
+	gl_FragDepth = gl_FragCoord.z + (stDepth * scale.z);
+}
diff --git a/gfx/gl/shaders/shadowDynamicPointStencil.gs b/gfx/gl/shaders/shadowDynamicPointStencil.gs
new file mode 100644
index 0000000..6d707ae
--- /dev/null
+++ b/gfx/gl/shaders/shadowDynamicPointStencil.gs
@@ -0,0 +1,32 @@
+#version 330 core
+#extension GL_ARB_viewport_array : enable
+
+const vec2[] corners = vec2[4](vec2(-1, -1), vec2(-1, 1), vec2(1, -1), vec2(1, 1));
+
+uniform mat4 viewProjection[4];
+uniform int viewProjections;
+uniform vec3 sizes[4];
+uniform float size;
+
+in ivec3 vworldPos[];
+
+flat out vec3 scale;
+out vec2 texCoord;
+
+layout(points) in;
+layout(triangle_strip, max_vertices = 16) out;
+
+void
+main()
+{
+	for (gl_Layer = 0; gl_Layer < viewProjections; ++gl_Layer) {
+		scale = 2.0 * size / sizes[gl_Layer];
+		vec4 pos = viewProjection[gl_Layer] * vec4(vworldPos[0], 1);
+		for (int c = 0; c < corners.length(); ++c) {
+			gl_Position = pos + vec4(scale.xy * corners[c], 0, 0);
+			texCoord = (corners[c] * 0.5) + 0.5;
+			EmitVertex();
+		}
+		EndPrimitive();
+	}
+}
diff --git a/gfx/gl/shaders/shadowDynamicPointStencil.vs b/gfx/gl/shaders/shadowDynamicPointStencil.vs
new file mode 100644
index 0000000..dadf9c2
--- /dev/null
+++ b/gfx/gl/shaders/shadowDynamicPointStencil.vs
@@ -0,0 +1,17 @@
+#version 330 core
+#extension GL_ARB_shading_language_420pack : enable
+
+layout(location = 0) in mat3 model;
+layout(location = 3) in ivec3 worldPos;
+uniform ivec3 viewPoint;
+uniform vec3 centre;
+
+out mat3 vmodel;
+out ivec3 vworldPos;
+
+void
+main()
+{
+	vmodel = model;
+	vworldPos = worldPos - viewPoint + ivec3(centre);
+}
diff --git a/gfx/gl/shadowMapper.cpp b/gfx/gl/shadowMapper.cpp
index 177bd22..ac161e2 100644
--- a/gfx/gl/shadowMapper.cpp
+++ b/gfx/gl/shadowMapper.cpp
@@ -3,11 +3,14 @@
 #include "collections.h"
 #include "game/gamestate.h"
 #include "gfx/gl/shaders/fs-shadowDynamicPointInstWithTextures.h"
+#include "gfx/gl/shaders/fs-shadowDynamicPointStencil.h"
 #include "gfx/gl/shaders/gs-commonShadowPoint.h"
 #include "gfx/gl/shaders/gs-shadowDynamicPointInstWithTextures.h"
+#include "gfx/gl/shaders/gs-shadowDynamicPointStencil.h"
 #include "gfx/gl/shaders/vs-shadowDynamicPoint.h"
 #include "gfx/gl/shaders/vs-shadowDynamicPointInst.h"
 #include "gfx/gl/shaders/vs-shadowDynamicPointInstWithTextures.h"
+#include "gfx/gl/shaders/vs-shadowDynamicPointStencil.h"
 #include "gfx/gl/shaders/vs-shadowLandmass.h"
 #include "gfx/gl/shadowStenciller.h"
 #include "gfx/renderable.h"
@@ -115,7 +118,7 @@ ShadowMapper::update(const SceneProvider & scene, const Direction3D & dir, const
 				return lightProjection * lightViewDir;
 			});
 	for (const auto p : std::initializer_list<const ShadowProgram *> {
-				 &landmess, &dynamicPoint, &dynamicPointInst, &dynamicPointInstWithTextures}) {
+				 &landmess, &dynamicPoint, &dynamicPointInst, &dynamicPointInstWithTextures, &stencilShadowProgram}) {
 		p->setView(out, sizes, lightViewPoint);
 	}
 	scene.shadows(*this);
@@ -166,3 +169,16 @@ ShadowMapper::DynamicPoint::setModel(const Location & location) const
 	glUniform(modelLoc, location.getRotationTransform());
 	glUniform(modelPosLoc, location.pos);
 }
+
+ShadowMapper::StencilShadowProgram::StencilShadowProgram() :
+	ShadowProgram {shadowDynamicPointStencil_vs, shadowDynamicPointStencil_gs, shadowDynamicPointStencil_fs}
+{
+}
+
+void
+ShadowMapper::StencilShadowProgram::use(const RelativePosition3D & centre, const float size) const
+{
+	Program::use();
+	glUniform(centreLoc, centre);
+	glUniform(sizeLoc, size);
+}
diff --git a/gfx/gl/shadowMapper.h b/gfx/gl/shadowMapper.h
index 19c3d23..3aa224e 100644
--- a/gfx/gl/shadowMapper.h
+++ b/gfx/gl/shadowMapper.h
@@ -50,8 +50,19 @@ public:
 		RequiredUniformLocation modelPosLoc {*this, "modelPos"};
 	};
 
+	class StencilShadowProgram : public ShadowProgram {
+	public:
+		StencilShadowProgram();
+		void use(const RelativePosition3D & centre, const float size) const;
+
+	private:
+		RequiredUniformLocation centreLoc {*this, "centre"};
+		RequiredUniformLocation sizeLoc {*this, "size"};
+	};
+
 	ShadowProgram landmess, dynamicPointInst, dynamicPointInstWithTextures;
 	DynamicPoint dynamicPoint;
+	StencilShadowProgram stencilShadowProgram;
 
 	// NOLINTNEXTLINE(hicpp-explicit-conversions)
 	operator GLuint() const