From a811ed57be4bd19e171a79ebd72dd18b5ff1afb1 Mon Sep 17 00:00:00 2001
From: Faerbit <faerbit@gmail.com>
Date: Wed, 4 Mar 2015 12:13:58 +0100
Subject: [PATCH] Now also blurring the edges of the flames.

---
 data/shader/flame.fsh |  9 ++++++++-
 data/shader/flame.gsh | 10 +++++-----
 graphics.cc           | 42 +++++++++++++++++++++++++++++++++---------
 3 files changed, 46 insertions(+), 15 deletions(-)

diff --git a/data/shader/flame.fsh b/data/shader/flame.fsh
index 9ae570f..7a4127d 100644
--- a/data/shader/flame.fsh
+++ b/data/shader/flame.fsh
@@ -4,7 +4,14 @@ in vec3 fColor;
 
 out vec4 oColor;
 
+uniform bool withColor;
+
 
 void main() {
-    oColor = vec4(fColor, 0.6);
+    if (withColor) {
+        oColor = vec4(fColor, 0.6);
+    }
+    else {
+        oColor = vec4(0.0, 0.0, 0.0, 0.0);
+    }
 }
diff --git a/data/shader/flame.gsh b/data/shader/flame.gsh
index 6fa8e4d..0fda82a 100644
--- a/data/shader/flame.gsh
+++ b/data/shader/flame.gsh
@@ -1,6 +1,6 @@
 #version 150
 
-uniform mat4 viewProjectionMatrix;
+uniform mat4 modelViewProjectionMatrix;
 uniform float time;
 uniform bool bottom;
 uniform bool left;
@@ -62,19 +62,19 @@ void main() {
             float rightAngle    = PI * 2.0 / resolution * (j+1);
 
             vec4 offset = vec4(cos(rightAngle) * downRadius, i, -sin(rightAngle) * downRadius, 0.0);
-            gl_Position = gl_in[0].gl_Position + viewProjectionMatrix * offset;
+            gl_Position = gl_in[0].gl_Position + modelViewProjectionMatrix * offset;
             EmitVertex();
 
             offset = vec4(cos(rightAngle) * upRadius, i + step, -sin(rightAngle) * upRadius, 0.0);
-            gl_Position = gl_in[0].gl_Position + viewProjectionMatrix * offset;
+            gl_Position = gl_in[0].gl_Position + modelViewProjectionMatrix * offset;
             EmitVertex();
 
             offset = vec4(cos(leftAngle) * downRadius, i, -sin(leftAngle) * downRadius, 0.0);
-            gl_Position = gl_in[0].gl_Position + viewProjectionMatrix * offset;
+            gl_Position = gl_in[0].gl_Position + modelViewProjectionMatrix * offset;
             EmitVertex();
 
             offset = vec4(cos(leftAngle) * upRadius, i + step, -sin(leftAngle) * upRadius, 0.0);
-            gl_Position = gl_in[0].gl_Position + viewProjectionMatrix * offset;
+            gl_Position = gl_in[0].gl_Position + modelViewProjectionMatrix * offset;
             EmitVertex();
 
             EndPrimitive();
diff --git a/graphics.cc b/graphics.cc
index 88db43e..f2dcc7e 100644
--- a/graphics.cc
+++ b/graphics.cc
@@ -278,18 +278,16 @@ void Graphics::render(double time)
     level->render(lightingShader, true, &lightingViewProjectionMatrix, &depthBiasVPs);
 
     // draw flames on top
+    flameShader->use();
     // cull faces to get consistent color while using alpha
     glEnable(GL_CULL_FACE);
     glCullFace(GL_BACK);
-    glEnable(GL_STENCIL_TEST);
-    glStencilFunc(GL_ALWAYS, 1, 0xFF); //Set any stencil to 1
-    glStencilFunc(GL_ALWAYS, 1, 0xFF);
-    glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
-    glStencilMask(0xFF);//write to stencil buffer
-    glClear(GL_STENCIL_BUFFER_BIT);//clear stencil buffer
 
-    flameShader->use();
+
+    // draw with colors
     flameShader->setUniform("viewProjectionMatrix", lightingViewProjectionMatrix);
+    flameShader->setUniform("modelViewProjectionMatrix", lightingViewProjectionMatrix);
+    flameShader->setUniform("withColor", true);
     flameShader->setUniform("time", (float) time);
     flameShader->setUniform("bottom", true);
     flameShader->setUniform("left", true);
@@ -302,10 +300,36 @@ void Graphics::render(double time)
     flameShader->setUniform("left", false);
     flame_positions->render();
 
-    glDisable(GL_CULL_FACE);
+    glDepthMask(GL_FALSE);
+
+    // draw slightly larger only for stencil buffer to blur edges
+    glEnable(GL_STENCIL_TEST);
+    glStencilFunc(GL_ALWAYS, 1, 0xFF); //Set any stencil to 1
+    glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
+    glStencilMask(0xFF);//write to stencil buffer
+    glClear(GL_STENCIL_BUFFER_BIT);//clear stencil buffer
+
+    glm::mat4 modelMatrix = glm::scale(glm::vec3(1.1f));
+    flameShader->setUniform("viewProjectionMatrix", lightingViewProjectionMatrix);
+    flameShader->setUniform("modelViewProjectionMatrix", lightingViewProjectionMatrix * modelMatrix);
+    flameShader->setUniform("withColor", false);
+    flameShader->setUniform("time", (float) time);
+    flameShader->setUniform("bottom", true);
+    flameShader->setUniform("left", true);
+    flame_positions->render();
+    flameShader->setUniform("left", false);
+    flame_positions->render();
+    flameShader->setUniform("bottom", false);
+    flameShader->setUniform("left", true);
+    flame_positions->render();
+    flameShader->setUniform("left", false);
+    flame_positions->render();
 
     glStencilFunc(GL_EQUAL, 1, 0xFF); //Pass test if stencil value is 1
-    glStencilMask(0x00); //don't write to stencil buffer
+    glStencilMask(0x00);// don't write to stencil buffer
+
+    glDepthMask(GL_TRUE);
+    glDisable(GL_CULL_FACE);
 
     flamePostShader->use();
     fullscreen_quad->render();