[Freeorion-programmers] SF.net SVN: freeorion:[2991] trunk/FreeOrion

[<geo...@us...>]

Revision: 2991
          http://freeorion.svn.sourceforge.net/freeorion/revision/?rev=2991&view=rev
Author:   geoffthemedio
Date:     2009-04-19 17:52:29 +0000 (Sun, 19 Apr 2009)

Log Message:
-----------
-Added a fragment shader that produces lines resembling horizontal scanlines, to be used for map fog of war
-Changed a define to a function to check for errors in ShaderProgram

Modified Paths:
--------------
    trunk/FreeOrion/UI/ShaderProgram.cpp

Added Paths:
-----------
    trunk/FreeOrion/default/shaders/
    trunk/FreeOrion/default/shaders/scanlines.frag

Modified: trunk/FreeOrion/UI/ShaderProgram.cpp
===================================================================
--- trunk/FreeOrion/UI/ShaderProgram.cpp	2009-04-19 12:42:41 UTC (rev 2990)
+++ trunk/FreeOrion/UI/ShaderProgram.cpp	2009-04-19 17:52:29 UTC (rev 2991)
@@ -9,21 +9,17 @@
 #include <fstream>
 
 
-#ifdef NDEBUG
-#  define CHECK_ERROR(fn, e)
-#else
-#  define CHECK_ERROR(fn, e)                                            \
-    if ((error = glGetError()) != GL_NO_ERROR) {                        \
-        std::cerr << fn " () :"                                         \
-                  << " GL error on " e ": "                             \
-                  << "'" << gluErrorString(error) << "'"                \
-                  << std::endl;                                         \
+namespace {
+    void CHECK_ERROR(const char* fn, const char* e) {
+        GLenum error = glGetError();
+        if (error != GL_NO_ERROR) {
+            std::cerr << fn << " () :"
+                      << " GL error on " << e << ": "
+                      << "'" << gluErrorString(error) << "'"
+                      << std::endl;
+        }
     }
-#endif
 
-namespace {
-    GLenum error;
-
     void GetShaderLog(GLuint shader, std::string& log) {
         log.clear();
         int logSize;
@@ -56,10 +52,8 @@
     std::string retval;
     std::ifstream ifs(filename.c_str());
     int c;
-    while ((c = ifs.get()) != std::ifstream::traits_type::eof()) {
+    while ((c = ifs.get()) != std::ifstream::traits_type::eof())
         retval += c;
-    }
-    std::cout << "ReadFile: " << std::endl << retval << std::endl;
     return retval;
 }
 

Added: trunk/FreeOrion/default/shaders/scanlines.frag
===================================================================
--- trunk/FreeOrion/default/shaders/scanlines.frag	                        (rev 0)
+++ trunk/FreeOrion/default/shaders/scanlines.frag	2009-04-19 17:52:29 UTC (rev 2991)
@@ -0,0 +1,13 @@
+
+// GLSL fragment shader that draws horizontal scanlines
+uniform float   scanline_spacing;                       // distance between repetitions of pattern
+
+const vec4      half_gray = vec4(0.0, 0.0, 0.0, 0.5);   // darkened pixels
+const vec4      transparent = vec4(1.0, 1.0, 1.0, 0.0); // undarkened pixels
+
+void main() {
+    if (mod(gl_FragCoord.y, scanline_spacing) >= (scanline_spacing / 2.0))
+        gl_FragColor = half_gray;
+    else
+        gl_FragColor = transparent;
+}
\ No newline at end of file