Use a shadow2DSampler for softer shadows

data/shaders/fs_default.glsl

@@ -4,7 +4,14 @@ uniform vec4 uColor;
 uniform vec3 uLightDirection;
 uniform vec3 uViewPosition;
 uniform sampler2D uAlbedoTexture;
+
+#define USE_SAMPLER2D_SHADOW 1
+
+#ifdef USE_SAMPLER2D_SHADOW
+uniform sampler2DShadow uShadowMap;
+#else
 uniform sampler2D uShadowMap;
+#endif
 
 in vec3 ioFragPosition;
 in vec3 ioFragNormal;
@@ -14,15 +21,49 @@ in vec4 ioFragPosLightSpace;
 
 out vec4 outColor;
 
+float ShadowCalculationPCF(vec4 frag_pos_light_space) {
+	vec3 projected_coordinates = frag_pos_light_space.xyz / frag_pos_light_space.w;
+	projected_coordinates = projected_coordinates * 0.5 + 0.5;
+
+	float current_depth = projected_coordinates.z;
+
+	float bias = 0.00;
+	bias = max(0.005 * (1.0 - dot(ioFragNormal, uLightDirection)), 0.003);
+
+	float shadow = 0.0;
+	vec2 texel_size = 1.0 / textureSize(uShadowMap, 0);
+	for (int x = -1; x <= 1; ++x) {
+		for (int y = -1; y <= 1; ++y) {
+#ifdef USE_SAMPLER2D_SHADOW
+			vec2 coordinate = projected_coordinates.xy + vec2(x, y) * texel_size;
+			float pcf_depth = texture(uShadowMap, vec3(coordinate, current_depth - bias));
+#else
+			float pcf_depth = texture(uShadowMap, projected_coordinates.xy).r;
+#endif
+			shadow += current_depth - bias > pcf_depth ? 1.0 : 0.0;
+		}
+	}
+
+	shadow /= 9.0;
+
+	return shadow;
+}
+
 float ShadowCalculation(vec4 frag_pos_light_space) {
 	vec3 projected_coordinates = frag_pos_light_space.xyz / frag_pos_light_space.w;
 	projected_coordinates = projected_coordinates * 0.5 + 0.5;
 
-	float closest_depth = texture(uShadowMap, projected_coordinates.xy).r;
 	float current_depth = projected_coordinates.z;
 
-	float bias = max(0.05 * (1.0 - dot(ioFragNormal, uLightDirection)), 0.005);
-	bias = 0.0;
+	float bias = 0.01;
+
+#ifdef USE_SAMPLER2D_SHADOW
+	float closest_depth = texture(uShadowMap, vec3(projected_coordinates.xy, current_depth - bias));
+#else
+	float closest_depth = texture(uShadowMap, projected_coordinates.xy).r;
+	bias = max(0.005 * (1.0 - dot(ioFragNormal, uLightDirection)), 0.003);
+#endif
+
 	return current_depth - bias > closest_depth ? 1.0 : 0.0;
 }
 
@@ -47,7 +88,8 @@ void main() {
 	vec4 specular = spec * vec4(0.5);
 
 	// shadow
-	float shadow = ShadowCalculation(ioFragPosLightSpace);
+//	float shadow = ShadowCalculation(ioFragPosLightSpace);
+	float shadow = ShadowCalculationPCF(ioFragPosLightSpace);
 	outColor = ambient + (1.0 - shadow) * (diffuse + specular);
 //
 //

src/modules/RenderModule.cc

@@ -215,7 +215,7 @@ void Light::DrawGui() {
 // Renderer
 //
 void Renderer::Initialize(int width, int height) {
-	mDefaultTexture.MakeGrid(128, Vector3f (0.8, 0.8f, 0.8f), Vector3f (0.2f, 0.2f, 0.2f));
+	mDefaultTexture.MakeGrid(128, Vector3f (0.8, 0.8f, 0.8f), Vector3f (0.7f, 0.7f, 0.7f));
 
 	gVertexArray.Initialize(1000, GL_STATIC_DRAW);
 	gCoordinateFrameMesh.Initialize(gVertexArray, 6);
@@ -411,7 +411,7 @@ void Renderer::RenderGl() {
 		mLight.UpdateMatrices();
 		glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
 		glEnable(GL_DEPTH_TEST);
-		glCullFace(GL_FRONT);
+//		glCullFace(GL_FRONT);
 		glUseProgram(mLight.mShadowMapProgram.mProgramId);
 		if (mLight.mShadowMapProgram.SetMat44("uLightSpaceMatrix", mLight.mLightSpaceMatrix) == -1) {
 			gLog ("Warning: Uniform %s not found!", "uLightSpaceMatrix");
@@ -419,7 +419,7 @@ void Renderer::RenderGl() {
 		RenderScene(mLight.mShadowMapProgram, mLight.mCamera);
 		mLight.mShadowMapTarget.RenderToLinearizedDepth(mLight.mCamera.mNear, mLight.mCamera.mFar, mLight.mCamera.mIsOrthographic);
 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
-	glCullFace(GL_BACK);
+//	glCullFace(GL_BACK);
 
 	// Regular rendering
 	glEnable(GL_LINE_SMOOTH);
@@ -508,6 +508,7 @@ void Renderer::RenderScene(RenderProgram &program, const Camera& camera) {
 
 	glActiveTexture(GL_TEXTURE0);
 	glBindTexture(GL_TEXTURE_2D, mLight.mShadowMapTarget.mDepthTexture);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_REF_TO_TEXTURE);
 	program.SetInt("uShadowMap",  0);
 
 	glActiveTexture(GL_TEXTURE1);

src/modules/RenderModule.h

@@ -36,7 +36,7 @@ struct Light {
 		mPosition (Vector3f(0.f, 3, 0.0f)),
 		mDirection (Vector3f(1.f, 1.f, 1.f)),
 		mShadowMapBias (0.004f),
-		mShadowMapSize (1024),
+		mShadowMapSize (2048),
 		mNear (-10.0f),
 		mFar (15.f),
 		mBBoxSize (35.f),

src/modules/RenderUtils.cc

@@ -351,12 +351,15 @@ void RenderTarget::Resize(int width, int height) {
 
 		glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, mWidth, mHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0);
 
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+		// Set parameters so that we can set a shadow2DSampler
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_REF_TO_TEXTURE);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+		float border_color[] = { 1.0f, 1.0f, 1.0f, 1.0f };
+		glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, border_color);
+
 
 		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, mDepthTexture, 0);