Create a shadowmap texture and upload light list

src/gl/dynlights/gl_shadowmap.cpp

@@ -28,27 +28,32 @@
 #include "gl/system/gl_debug.h"
 #include "gl/renderer/gl_renderer.h"
 #include "gl/renderer/gl_postprocessstate.h"
+#include "gl/renderer/gl_renderbuffers.h"
 #include "gl/shaders/gl_shadowmapshader.h"
 #include "r_state.h"
 
 void FShadowMap::Clear()
 {
+	if (mLightList != 0)
+	{
+		glDeleteBuffers(1, (GLuint*)&mLightList);
+		mLightList = 0;
+	}
+
 	mLightBSP.Clear();
 }
 
 void FShadowMap::Update()
 {
-	TThinkerIterator<ADynamicLight> it(STAT_DLIGHT);
-	while (true)
-	{
-		ADynamicLight *light = it.Next();
-		if (!light) break;
-	}
+	UploadLights();
 
 	FGLDebug::PushGroup("ShadowMap");
 	FGLPostProcessState savedState;
 
+	GLRenderer->mBuffers->BindShadowMapFB();
+
 	GLRenderer->mShadowMapShader->Bind();
+	glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, mLightList);
 	glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 2, mLightBSP.GetNodesBuffer());
 	glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 3, mLightBSP.GetSegsBuffer());
 
@@ -58,8 +63,41 @@ void FShadowMap::Update()
 	const auto &viewport = GLRenderer->mScreenViewport;
 	glViewport(viewport.left, viewport.top, viewport.width, viewport.height);
 
+	glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, 0);
 	glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 2, 0);
 	glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 3, 0);
 
 	FGLDebug::PopGroup();
 }
+
+void FShadowMap::UploadLights()
+{
+	lights.Clear();
+
+	TThinkerIterator<ADynamicLight> it(STAT_DLIGHT);
+	while (true)
+	{
+		ADynamicLight *light = it.Next();
+		if (!light) break;
+
+		lights.Push(light->X());
+		lights.Push(light->Y());
+		lights.Push(light->Z());
+		lights.Push(light->GetRadius());
+
+		if (lights.Size() == 1024) // Only 1024 lights for now
+			break;
+	}
+
+	while (lights.Size() < 1024 * 4)
+		lights.Push(0.0f);
+
+	if (mLightList == 0)
+		glGenBuffers(1, (GLuint*)&mLightList);
+
+	int oldBinding = 0;
+	glGetIntegerv(GL_SHADER_STORAGE_BUFFER_BINDING, &oldBinding);
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, mLightList);
+	glBufferData(GL_SHADER_STORAGE_BUFFER, sizeof(float) * lights.Size(), &lights[0], GL_STATIC_DRAW);
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, oldBinding);
+}

src/gl/dynlights/gl_shadowmap.h

@@ -13,7 +13,11 @@ public:
 	void Update();
 
 private:
+	void UploadLights();
+
 	FLightBSP mLightBSP;
+	int mLightList = 0;
+	TArray<float> lights;
 
 	FShadowMap(const FShadowMap &) = delete;
 	FShadowMap &operator=(FShadowMap &) = delete;

src/gl/renderer/gl_renderbuffers.cpp

@@ -741,6 +741,44 @@ void FGLRenderBuffers::BindEyeFB(int eye, bool readBuffer)
 	glBindFramebuffer(readBuffer ? GL_READ_FRAMEBUFFER : GL_FRAMEBUFFER, mEyeFBs[eye]);
 }
 
+//==========================================================================
+//
+// Shadow map texture and frame buffers
+//
+//==========================================================================
+
+void FGLRenderBuffers::BindShadowMapFB()
+{
+	CreateShadowMap();
+	glBindFramebuffer(GL_FRAMEBUFFER, mShadowMapFB);
+}
+
+void FGLRenderBuffers::BindShadowMapTexture(int texunit)
+{
+	CreateShadowMap();
+	glActiveTexture(GL_TEXTURE0 + texunit);
+	glBindTexture(GL_TEXTURE_2D, mShadowMapTexture);
+}
+
+void FGLRenderBuffers::CreateShadowMap()
+{
+	if (mShadowMapTexture != 0)
+		return;
+
+	GLint activeTex, textureBinding, frameBufferBinding;
+	glGetIntegerv(GL_ACTIVE_TEXTURE, &activeTex);
+	glActiveTexture(GL_TEXTURE0);
+	glGetIntegerv(GL_TEXTURE_BINDING_2D, &textureBinding);
+	glGetIntegerv(GL_FRAMEBUFFER_BINDING, &frameBufferBinding);
+
+	mShadowMapTexture = Create2DTexture("ShadowMap", GL_R32F, 1024, 1024);
+	mShadowMapFB = CreateFrameBuffer("ShadowMapFB", mShadowMapTexture);
+
+	glBindTexture(GL_TEXTURE_2D, textureBinding);
+	glActiveTexture(activeTex);
+	glBindFramebuffer(GL_FRAMEBUFFER, frameBufferBinding);
+}
+
 //==========================================================================
 //
 // Makes the scene frame buffer active (multisample, depth, stecil, etc.)

src/gl/renderer/gl_renderbuffers.h

@@ -49,6 +49,9 @@ public:
 	void BindEyeTexture(int eye, int texunit);
 	void BindEyeFB(int eye, bool readBuffer = false);
 
+	void BindShadowMapFB();
+	void BindShadowMapTexture(int index);
+
 	enum { NumBloomLevels = 4 };
 	FGLBloomTextureLevel BloomLevels[NumBloomLevels];
 
@@ -89,6 +92,7 @@ private:
 	void CreateBloom(int width, int height);
 	void CreateExposureLevels(int width, int height);
 	void CreateEyeBuffers(int eye);
+	void CreateShadowMap();
 	void CreateAmbientOcclusion(int width, int height);
 	GLuint Create2DTexture(const FString &name, GLuint format, int width, int height, const void *data = nullptr);
 	GLuint Create2DMultisampleTexture(const FString &name, GLuint format, int width, int height, int samples, bool fixedSampleLocations);
@@ -133,6 +137,10 @@ private:
 	TArray<GLuint> mEyeTextures;
 	TArray<GLuint> mEyeFBs;
 
+	// Shadow map texture
+	GLuint mShadowMapTexture = 0;
+	GLuint mShadowMapFB = 0;
+
 	static bool FailedCreate;
 	static bool BuffersActive;
 };

wadsrc/static/shaders/glsl/shadowmap.fp

@@ -16,6 +16,11 @@ struct GPUSeg
 	vec4 bSolid;
 };
 
+layout(std430, binding = 1) buffer LightList
+{
+	vec4 lights[];
+};
+
 layout(std430, binding = 2) buffer LightNodes
 {
 	GPUNode bspNodes[];
@@ -112,5 +117,16 @@ float rayTest(vec2 from, vec2 to)
 
 void main()
 {
-	FragColor = vec4(rayTest(vec2(0.0, 0.0), vec2(1.0, 1.0)));
+	int lightIndex = int(gl_FragCoord.y);
+	int x = int(gl_FragCoord.x);
+
+	vec4 light = lights[lightIndex];
+	float radius = light.w;
+	vec2 lightpos = light.xy;
+	vec2 pixelpos = lightpos + vec2(10.0);
+
+	if (radius > 0.0)
+		FragColor = vec4(rayTest(lightpos, pixelpos), 0.0, 0.0, 1.0);
+	else
+		FragColor = vec4(1.0, 0.0, 0.0, 1.0);
 }