Optimize multipass texture binding and drop redundant sampler updates

Author: DanielsCreation

src/OpenCOVER/plugins/hlrs/LamurePointCloud/LamureRenderer.cpp

@@ -844,6 +844,23 @@ struct PointsDrawCallback : public virtual osg::Drawable::DrawCallback
             const float scale_radius_combined = s.scale_radius * s.scale_element;
             const float scale_proj_pass = opencover::cover->getScale() * static_cast<float>(vpHeight) * 0.5f * projection_matrix.data_array[5];
 
+            const auto bindTexture2DToUnit = [](GLuint unit, GLuint texture) {
+#if defined(GL_VERSION_4_5)
+                if (GLEW_VERSION_4_5) {
+                    glBindTextureUnit(unit, texture);
+                    return;
+                }
+#endif
+#if defined(GL_ARB_direct_state_access)
+                if (GLEW_ARB_direct_state_access) {
+                    glBindTextureUnit(unit, texture);
+                    return;
+                }
+#endif
+                glActiveTexture(GL_TEXTURE0 + unit);
+                glBindTexture(GL_TEXTURE_2D, texture);
+            };
+
             // --- PASS 1: Depth pre-pass (depth-only, kreisförmiges discard im FS)
             glBindFramebuffer(GL_FRAMEBUFFER, target.fbo);
             glViewport(0, 0, vpWidth, vpHeight);
@@ -918,10 +935,7 @@ struct PointsDrawCallback : public virtual osg::Drawable::DrawCallback
             glViewport(0, 0, vpWidth, vpHeight);
 
             // Tiefe aus Pass 1
-            glActiveTexture(GL_TEXTURE0);
-            glBindTexture(GL_TEXTURE_2D, target.depth_texture);
-            if (_renderer->getSurfelPass2Shader().depth_texture_loc >= 0)
-                glUniform1i(_renderer->getSurfelPass2Shader().depth_texture_loc, 0);
+            bindTexture2DToUnit(0, target.depth_texture);
 
             // Globale Uniforms für VS/GS/FS
             if (_renderer->getSurfelPass2Shader().viewport_loc            >= 0) glUniform2f(_renderer->getSurfelPass2Shader().viewport_loc, viewport.x, viewport.y);
@@ -994,25 +1008,10 @@ struct PointsDrawCallback : public virtual osg::Drawable::DrawCallback
             glUseProgram(_renderer->getSurfelPass3Shader().program);
 
             // G-Buffer
-            glActiveTexture(GL_TEXTURE0);
-            glBindTexture(GL_TEXTURE_2D, target.texture_color);
-            if (_renderer->getSurfelPass3Shader().in_color_texture_loc >= 0)
-                glUniform1i(_renderer->getSurfelPass3Shader().in_color_texture_loc, 0);
-
-            glActiveTexture(GL_TEXTURE1);
-            glBindTexture(GL_TEXTURE_2D, target.texture_normal);
-            if (_renderer->getSurfelPass3Shader().in_normal_texture_loc >= 0)
-                glUniform1i(_renderer->getSurfelPass3Shader().in_normal_texture_loc, 1);
-
-            glActiveTexture(GL_TEXTURE2);
-            glBindTexture(GL_TEXTURE_2D, target.texture_position);
-            if (_renderer->getSurfelPass3Shader().in_vs_position_texture_loc >= 0)
-                glUniform1i(_renderer->getSurfelPass3Shader().in_vs_position_texture_loc, 2);
-
-            glActiveTexture(GL_TEXTURE3);
-            glBindTexture(GL_TEXTURE_2D, target.depth_texture);
-            if (_renderer->getSurfelPass3Shader().in_depth_texture_loc >= 0)
-                glUniform1i(_renderer->getSurfelPass3Shader().in_depth_texture_loc, 3);
+            bindTexture2DToUnit(0, target.texture_color);
+            bindTexture2DToUnit(1, target.texture_normal);
+            bindTexture2DToUnit(2, target.texture_position);
+            bindTexture2DToUnit(3, target.depth_texture);
 
             // View-space lighting Setup
             scm::math::mat4 viewMat = view_matrix;

src/OpenCOVER/plugins/hlrs/LamurePointCloud/shaders/vis/vis_surfel_util.glsl

@@ -144,26 +144,20 @@ bool scale_anisotropic_pixels_depth(
 
     float ru = length(su - s0);
     float rv = length(sv - s0);
-    float d_pxC = clamp(2.0 * max(ru, rv), min_screen_size, max_screen_size);
-    if (d_pxC <= UTIL_EPS) return false;
-
-    float R = 0.5 * d_pxC;
-    float m = max(ru, rv);
-    float iso = (m > UTIL_EPS) ? (R / m) : 1.0;
-    float su_s = (ru > UTIL_EPS) ? (R / ru) : 1.0;
-    float sv_s = (rv > UTIL_EPS) ? (R / rv) : 1.0;
-
-    // Smoothly cap extreme anisotropy to avoid popping near degeneracies
-    const float Amax = 3.0; // desired max anisotropy ratio
-    float ratio = (ru > rv) ? (ru / max(rv, UTIL_EPS)) : (rv / max(ru, UTIL_EPS));
-    float t = clamp((ratio - Amax) / (Amax * 0.5), 0.0, 1.0); // blend towards isotropic when exceeding cap
-    su_s = mix(su_s, iso, t);
-    sv_s = mix(sv_s, iso, t);
+
+    float du = clamp(2.0 * ru, min_screen_size, max_screen_size);
+    float dv = clamp(2.0 * rv, min_screen_size, max_screen_size);
+    float r_u = 0.5f * du;
+    float r_v = 0.5f * dv;
+
+    float su_s = (ru > UTIL_EPS) ? (r_u / ru) : 0.0f;
+    float sv_s = (rv > UTIL_EPS) ? (r_v / rv) : 0.0f;
 
     step_u_ws *= su_s;
     step_v_ws *= sv_s;
-    out_pixel_diameter = d_pxC;
-    return true;
+
+    out_pixel_diameter = max(du, dv);
+    return (du > UTIL_EPS) || (dv > UTIL_EPS);
 }
 
 // Anisotropic pixel-scaling (no depth): same as above, but does not report NDC depth
@@ -187,25 +181,20 @@ bool scale_anisotropic_pixels(
 
     float ru = length(su - s0);
     float rv = length(sv - s0);
-    float d_pxC = clamp(2.0 * max(ru, rv), min_screen_size, max_screen_size);
-    if (d_pxC <= UTIL_EPS) return false;
 
-    float R = 0.5 * d_pxC;
-    float m  = max(ru, rv);
-    float iso = (m > UTIL_EPS) ? (R / m) : 1.0;
-    float su_s = (ru > UTIL_EPS) ? (R / ru) : 1.0;
-    float sv_s = (rv > UTIL_EPS) ? (R / rv) : 1.0;
+    float du = clamp(2.0 * ru, min_screen_size, max_screen_size);
+    float dv = clamp(2.0 * rv, min_screen_size, max_screen_size);
+    float r_u = 0.5f * du;
+    float r_v = 0.5f * dv;
 
-    const float Amax = 3.0;
-    float ratio = (ru > rv) ? (ru / max(rv, UTIL_EPS)) : (rv / max(ru, UTIL_EPS));
-    float t = clamp((ratio - Amax) / (Amax * 0.5), 0.0, 1.0);
-    su_s = mix(su_s, iso, t);
-    sv_s = mix(sv_s, iso, t);
+    float su_s = (ru > UTIL_EPS) ? (r_u / ru) : 0.0f;
+    float sv_s = (rv > UTIL_EPS) ? (r_v / rv) : 0.0f;
 
     step_u_ws *= su_s;
     step_v_ws *= sv_s;
-    out_pixel_diameter = d_pxC;
-    return true;
+
+    out_pixel_diameter = max(du, dv);
+    return (du > UTIL_EPS) || (dv > UTIL_EPS);
 }
 
 // Isotropic scaling with depth reporting (compat variant for other shaders)