Merge branch 'master' of https://github.com/supertuxkart/stk-code

data/shaders/pointlight.vert

@@ -18,35 +18,105 @@ in vec3 Position;
 in float Energy;
 in vec3 Color;
 
-in vec2 Corner;
-
 flat out vec3 center;
 flat out float energy;
 flat out vec3 col;
 
 const float zNear = 1.;
 
+// Code borrowed from https://software.intel.com/en-us/articles/deferred-rendering-for-current-and-future-rendering-pipelines
+// Maths explanations are found here http://www.gamasutra.com/view/feature/131351/the_mechanics_of_robust_stencil_.php?page=6
+
+vec2 UpdateClipRegionRoot(float nc,          /* Tangent plane x/y normal coordinate (view space) */
+                          float lc,          /* Light x/y coordinate (view space) */
+                          float lz,          /* Light z coordinate (view space) */
+                          float lightRadius,
+                          float cameraScale  /* Project scale for coordinate (_11 or _22 for x/y respectively) */)
+{
+    float nz = (lightRadius - nc * lc) / lz;
+    float pz = (lc * lc + lz * lz - lightRadius * lightRadius) /
+               (lz - (nz / nc) * lc);
+
+    if (pz > 0.) {
+        float c = -nz * cameraScale / nc;
+        if (nc > 0.) // Left side boundary
+            return vec2(c, 1.);
+        else // Right side boundary
+            return vec2(-1., c);
+    }
+    return vec2(-1., 1.);
+}
+
+vec2 UpdateClipRegion(float lc,          /* Light x/y coordinate (view space) */
+                      float lz,          /* Light z coordinate (view space) */
+                      float lightRadius,
+                      float cameraScale  /* Project scale for coordinate (_11 or _22 for x/y respectively) */)
+{
+    float rSq = lightRadius * lightRadius;
+    float lcSqPluslzSq = lc * lc + lz * lz;
+    float d = rSq * lc * lc - lcSqPluslzSq * (rSq - lz * lz);
+
+    // The camera is inside lignt bounding sphere, quad fits whole screen
+    if (d <= 0.)
+        return vec2(-1., 1.);
+
+    float a = lightRadius * lc;
+    float b = sqrt(d);
+    float nx0 = (a + b) / lcSqPluslzSq;
+    float nx1 = (a - b) / lcSqPluslzSq;
+
+    vec2 clip0 = UpdateClipRegionRoot(nx0, lc, lz, lightRadius, cameraScale);
+    vec2 clip1 = UpdateClipRegionRoot(nx1, lc, lz, lightRadius, cameraScale);
+    return vec2(max(clip0.x, clip1.x), min(clip0.y, clip1.y));
+}
+
+// Returns bounding box [min.x, max.x, min.y, max.y] in clip [-1, 1] space.
+vec4 ComputeClipRegion(vec3 lightPosView, float lightRadius)
+{
+    if (lightPosView.z + lightRadius >= zNear) {
+        vec2 clipX = UpdateClipRegion(lightPosView.x, lightPosView.z, lightRadius, ProjectionMatrix[0][0]);
+        vec2 clipY = UpdateClipRegion(lightPosView.y, lightPosView.z, lightRadius, ProjectionMatrix[1][1]);
+
+        return vec4(clipX, clipY);
+    }
+
+    return vec4(0.);
+}
+
+
 void main(void)
 {
-    // Beyond that value, light is too attenuated
-    float r = 30 * Energy;
-    center = Position;
-    energy = Energy;
+    float radius = 20. * Energy;
     vec4 Center = ViewMatrix * vec4(Position, 1.);
-    vec4 ProjectedCornerPosition = ProjectionMatrix * (Center + r * vec4(Corner, 0., 0.));
-    float adjustedDepth = ProjectedCornerPosition.z;
-    if (Center.z > zNear) // Light is in front of the cam
-    {
-        adjustedDepth = max(Center.z - r, zNear);
-    }
-    else if (Center.z + r > zNear) // Light is behind the cam but in range
+    Center /= Center.w;
+
+    vec2 ProjectedCornerPosition;
+    vec4 clip = ComputeClipRegion(Center.xyz, radius);
+    switch (gl_VertexID)
     {
-        adjustedDepth = zNear;
+    case 0:
+        ProjectedCornerPosition = clip.xz;
+        break;
+    case 1:
+        ProjectedCornerPosition = clip.xw;
+        break;
+    case 2:
+        ProjectedCornerPosition = clip.yz;
+        break;
+    case 3:
+        ProjectedCornerPosition = clip.yw;
+        break;
     }
 
-    ProjectedCornerPosition /= ProjectedCornerPosition.w;
-    ProjectedCornerPosition.zw = (ProjectionMatrix * vec4(0., 0., adjustedDepth, 1.)).zw;
-    ProjectedCornerPosition.xy *= ProjectedCornerPosition.w;
+    // Work out nearest depth for quad Z
+    // Clamp to near plane in case this light intersects the near plane... don't want our quad to be clipped
+    float quadDepth = max(zNear, Center.z - radius);
+
+    // Project quad depth into clip space
+    vec4 quadClip = ProjectionMatrix * vec4(0., 0., quadDepth, 1.0f);
+    gl_Position = vec4(ProjectedCornerPosition, quadClip.z / quadClip.w, 1.);
+
     col = Color;
-    gl_Position = ProjectedCornerPosition;
+    center = Position;
+    energy = Energy;
 }

src/graphics/glwrap.cpp

@@ -304,6 +304,11 @@ GLuint getDepthTexture(irr::video::ITexture *tex)
 
 std::set<irr::video::ITexture *> AlreadyTransformedTexture;
 
+void resetTextureTable()
+{
+    AlreadyTransformedTexture.clear();
+}
+
 void compressTexture(irr::video::ITexture *tex, bool srgb)
 {
     if (AlreadyTransformedTexture.find(tex) != AlreadyTransformedTexture.end())

src/graphics/glwrap.hpp

@@ -159,6 +159,7 @@ GLint LoadProgram(Types ... args)
 
 GLuint getTextureGLuint(irr::video::ITexture *tex);
 GLuint getDepthTexture(irr::video::ITexture *tex);
+void resetTextureTable();
 void compressTexture(irr::video::ITexture *tex, bool srgb);
 void blitFBO(GLuint Src, GLuint Dst, size_t width, size_t height);
 

src/graphics/shaders.cpp

@@ -1754,7 +1754,6 @@ namespace LightShader
     GLuint PointLightShader::attrib_Position;
     GLuint PointLightShader::attrib_Color;
     GLuint PointLightShader::attrib_Energy;
-    GLuint PointLightShader::attrib_Corner;
     GLuint PointLightShader::uniform_ntex;
     GLuint PointLightShader::uniform_dtex;
     GLuint PointLightShader::uniform_spec;
@@ -1773,7 +1772,6 @@ namespace LightShader
         attrib_Position = glGetAttribLocation(Program, "Position");
         attrib_Color = glGetAttribLocation(Program, "Color");
         attrib_Energy = glGetAttribLocation(Program, "Energy");
-        attrib_Corner = glGetAttribLocation(Program, "Corner");
         uniform_ntex = glGetUniformLocation(Program, "ntex");
         uniform_dtex = glGetUniformLocation(Program, "dtex");
         uniform_spec = glGetUniformLocation(Program, "spec");
@@ -1782,10 +1780,6 @@ namespace LightShader
         glGenVertexArrays(1, &vao);
         glBindVertexArray(vao);
 
-        glBindBuffer(GL_ARRAY_BUFFER, SharedObject::billboardvbo);
-        glEnableVertexAttribArray(attrib_Corner);
-        glVertexAttribPointer(attrib_Corner, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), 0);
-
         glGenBuffers(1, &vbo);
         glBindBuffer(GL_ARRAY_BUFFER, vbo);
         glBufferData(GL_ARRAY_BUFFER, MAXLIGHT * sizeof(PointLightInfo), 0, GL_DYNAMIC_DRAW);

src/graphics/shaders.hpp

@@ -434,7 +434,6 @@ namespace LightShader
     public:
         static GLuint Program;
         static GLuint attrib_Position, attrib_Energy, attrib_Color;
-        static GLuint attrib_Corner;
         static GLuint uniform_ntex, uniform_dtex, uniform_spec, uniform_screen;
         static GLuint vbo;
         static GLuint vao;

src/tracks/track.cpp

@@ -28,6 +28,7 @@
 #include "config/user_config.hpp"
 #include "graphics/camera.hpp"
 #include "graphics/CBatchingMesh.hpp"
+#include "graphics/glwrap.hpp"
 #include "graphics/irr_driver.hpp"
 #include "graphics/lod_node.hpp"
 #include "graphics/material_manager.hpp"
@@ -206,6 +207,8 @@ void Track::cleanup()
     ItemManager::destroy();
 
     ParticleKindManager::get()->cleanUpTrackSpecificGfx();
+    // Clear remainder of transformed textures
+    resetTextureTable();
 
     for(unsigned int i=0; i<m_animated_textures.size(); i++)
     {