Make shaders run as efficient as possible

data/shaders/instanced_object_pass2.frag

@@ -8,14 +8,14 @@ flat in sampler2D handle;
 flat in sampler2D secondhandle;
 #endif
 
-uniform vec2 color_change;
+uniform float color_change;
 
 in vec2 uv;
 in vec4 color;
 out vec4 FragColor;
 
 vec3 getLightFactor(vec3 diffuseMatColor, vec3 specularMatColor, float specMapValue, float emitMapValue);
-float rgbToValue(vec3 c);
+vec3 rgbToHsv(vec3 c);
 vec3 hsvToRgb(vec3 c);
 
 void main(void)
@@ -33,10 +33,12 @@ void main(void)
     float emitmap = texture(SpecMap, uv).b;
 #endif
 
-    if (color_change.x > 0.0)
+    if (color_change > 0.0)
     {
-        vec3 new_color = hsvToRgb(vec3(color_change.x, color_change.y, rgbToValue(col.rgb)));
+        vec3 old_hsv = rgbToHsv(col.rgb);
-        col = vec4(new_color.b, new_color.g, new_color.r, col.a);
+        old_hsv.y = max(old_hsv.y, 0.93);
+        vec3 new_color = hsvToRgb(vec3(color_change, old_hsv.y, old_hsv.z));
+        col = vec4(new_color.r, new_color.g, new_color.b, col.a);
     }
 
     col.xyz *= pow(color.xyz, vec3(2.2));

data/shaders/object_pass2.frag

@@ -6,14 +6,14 @@ uniform sampler2D Albedo;
 uniform sampler2D SpecMap;
 #endif
 
-uniform vec2 color_change;
+uniform float color_change;
 
 in vec2 uv;
 in vec4 color;
 out vec4 FragColor;
 
 vec3 getLightFactor(vec3 diffuseMatColor, vec3 specularMatColor, float specMapValue, float emitMapValue);
-float rgbToValue(vec3 c);
+vec3 rgbToHsv(vec3 c);
 vec3 hsvToRgb(vec3 c);
 
 void main(void)
@@ -27,10 +27,12 @@ void main(void)
     vec4 col = texture(Albedo, uv);
 #endif
 
-    if (color_change.x > 0.0)
+    if (color_change > 0.0)
     {
-        vec3 new_color = hsvToRgb(vec3(color_change.x, color_change.y, rgbToValue(col.rgb)));
+        vec3 old_hsv = rgbToHsv(col.rgb);
-        col = vec4(new_color.b, new_color.g, new_color.r, col.a);
+        old_hsv.y = max(old_hsv.y, 0.93);
+        vec3 new_color = hsvToRgb(vec3(color_change, old_hsv.y, old_hsv.z));
+        col = vec4(new_color.r, new_color.g, new_color.b, col.a);
     }
 
     col.xyz *= pow(color.xyz, vec3(2.2));

data/shaders/utils/rgb_conversion.frag

@@ -9,15 +9,6 @@ vec3 rgbToHsv(vec3 c)
     return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
 }
 
-float rgbToValue(vec3 c)
-{
-    vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
-    vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
-    vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
-
-    return q.x;
-}
-
 vec3 hsvToRgb(vec3 c)
 {
     vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);

src/graphics/render_geometry.cpp

@@ -153,10 +153,11 @@ public:
                            4, "SpecMap", ST_TRILINEAR_ANISOTROPIC_FILTERED);
     }   // InstancedObjectPass2Shader
 
-    void setHueSaturation(float hue, float saturation) const
+    virtual bool changeHue(float hue = 0.0f) const OVERRIDE
     {
-        glUniform2f(m_color_change_location, hue, saturation);
+        glUniform1f(m_color_change_location, hue);
-    }   // setHueSaturation
+        return true;
+    }   // changeHue
 };   // InstancedObjectPass2Shader
 
 // ============================================================================
@@ -997,23 +998,17 @@ void draw(const T *Shader, const GLMesh *mesh, uniforms... Args)
     GLenum itype = mesh->IndexType;
     size_t count = mesh->IndexCount;
 
-    const Shaders::ObjectPass2Shader* op2s = dynamic_cast<const Shaders::ObjectPass2Shader*>
+    const video::E_RENDER_TYPE rt = mesh->mb->getRenderType();
-        (Shader);
+    const bool need_change_hue = (rt != video::ERT_DEFAULT);
-    if (op2s)
+    if (need_change_hue)
     {
-        const video::E_RENDER_TYPE rt = mesh->mb->getRenderType();
         if (rt == video::ERT_RED)
         {
-            op2s->setHueSaturation(0.69f, 0.97f);
+            Shader->changeHue(1.0f);
         }
         else if (rt == video::ERT_BLUE)
         {
-            op2s->setHueSaturation(0.01f, 0.97f);
+            Shader->changeHue(0.66f);
-        }
-        else
-        {
-            // Reset if not using custom render type
-            op2s->setHueSaturation(0.0f, 0.0f);
         }
     }
 
@@ -1021,6 +1016,13 @@ void draw(const T *Shader, const GLMesh *mesh, uniforms... Args)
     glDrawElementsBaseVertex(ptype, (int)count, itype,
                              (GLvoid *)mesh->vaoOffset,
                              (int)mesh->vaoBaseVertex);
+
+    if (need_change_hue)
+    {
+        // Reset after changing
+        Shader->changeHue();
+    }
+
 }   // draw
 
 // ----------------------------------------------------------------------------
@@ -1302,47 +1304,31 @@ void renderInstancedMeshes2ndPass(const std::vector<GLuint> &Prefilled_tex, Args
         TexExpander<typename T::InstancedSecondPassShader>::template
             ExpandTex(*mesh, T::SecondPassTextures, Prefilled_tex[0],
                       Prefilled_tex[1], Prefilled_tex[2]);
-        T::InstancedSecondPassShader::getInstance()->setUniforms(args...);
-        glDrawElementsIndirect(GL_TRIANGLES, GL_UNSIGNED_SHORT,
-           (const void*)((SolidPassCmd::getInstance()->Offset[T::MaterialType] + i)
-           * sizeof(DrawElementsIndirectCommand)));
-    }
-}   // renderInstancedMeshes2ndPass
-
-// ----------------------------------------------------------------------------
-template<>
-void renderInstancedMeshes2ndPass<DefaultMaterial>(const std::vector<GLuint> &Prefilled_tex)
-{
-    std::vector<GLMesh *> &meshes = DefaultMaterial::InstancedList::getInstance()->SolidPass;
-    DefaultMaterial::InstancedSecondPassShader::getInstance()->use();
-    glBindVertexArray(VAOManager::getInstance()->getInstanceVAO(DefaultMaterial::VertexType,
-                                                                DefaultMaterial::Instance));
-    for (unsigned i = 0; i < meshes.size(); i++)
-    {
-        GLMesh *mesh = meshes[i];
-        TexExpander<DefaultMaterial::InstancedSecondPassShader>::template
-            ExpandTex(*mesh, DefaultMaterial::SecondPassTextures, Prefilled_tex[0],
-                      Prefilled_tex[1], Prefilled_tex[2]);
 
         const video::E_RENDER_TYPE rt = mesh->mb->getRenderType();
-        if (rt == video::ERT_RED)
+        const bool need_change_hue = (rt != video::ERT_DEFAULT);
+        if (need_change_hue)
         {
-            DefaultMaterial::InstancedSecondPassShader::getInstance()->setHueSaturation(0.69f, 0.97f);
+            if (rt == video::ERT_RED)
-        }
+            {
-        else if (rt == video::ERT_BLUE)
+                T::InstancedSecondPassShader::getInstance()->changeHue(1.0f);
-        {
+            }
-            DefaultMaterial::InstancedSecondPassShader::getInstance()->setHueSaturation(0.01f, 0.97f);
+            else if (rt == video::ERT_BLUE)
-        }
+            {
-        else
+                T::InstancedSecondPassShader::getInstance()->changeHue(0.66f);
-        {
+            }
-            // Reset if not using custom render type
-            DefaultMaterial::InstancedSecondPassShader::getInstance()->setHueSaturation(0.0f, 0.0f);
         }
 
-        DefaultMaterial::InstancedSecondPassShader::getInstance()->setUniforms();
+        T::InstancedSecondPassShader::getInstance()->setUniforms(args...);
         glDrawElementsIndirect(GL_TRIANGLES, GL_UNSIGNED_SHORT, 
-           (const void*)((SolidPassCmd::getInstance()->Offset[DefaultMaterial::MaterialType] + i)
+           (const void*)((SolidPassCmd::getInstance()->Offset[T::MaterialType] + i)
            * sizeof(DrawElementsIndirectCommand)));
+
+        if (need_change_hue)
+        {
+            // Reset after changing
+            T::InstancedSecondPassShader::getInstance()->changeHue();
+        }
     }
 }   // renderInstancedMeshes2ndPass
 

src/graphics/shaders.hpp

@@ -150,10 +150,11 @@ public:
         GLint m_color_change_location;
     public:
         ObjectPass2Shader();
-        void setHueSaturation(float hue, float saturation) const
+        virtual bool changeHue(float hue = 0.0f) const OVERRIDE
         {
-            glUniform2f(m_color_change_location, hue, saturation);
+            glUniform1f(m_color_change_location, hue);
-        }   // setHueSaturation
+            return true;
+        }   // changeHue
     };   // ObjectPass2Shader
 
     // ========================================================================

src/graphics/texture_shader.hpp

@@ -21,6 +21,7 @@
 #include "graphics/central_settings.hpp"
 #include "graphics/gl_headers.hpp"
 #include "graphics/shader.hpp"
+#include "utils/cpp2011.hpp"
 
 #include <assert.h>
 #include <functional>
@@ -241,6 +242,12 @@ public:
             glDeleteSamplers(1, &m_sampler_ids[i]);
     }   // ~TextureShader
 
+    /** Override this class and return true if a shader can set different hue.
+     */
+    virtual bool changeHue(float hue = 0.0f) const
+    {
+        return false;
+    }   // changeHue
 
 };   // class TextureShader