Output convenience uniforms per effect. Also, do not rely on the preprocessor support...
authorSteinar H. Gunderson <sgunderson@bigfoot.com>
Mon, 1 Oct 2012 16:20:35 +0000 (18:20 +0200)
committerSteinar H. Gunderson <sgunderson@bigfoot.com>
Mon, 1 Oct 2012 16:20:35 +0000 (18:20 +0200)
effect.cpp
effect.h
effect_chain.cpp

index f89b1a9..927acd5 100644 (file)
@@ -1,3 +1,4 @@
+#include <stdio.h>
 #include <string.h>
 #include <assert.h>
 #include "effect.h"
@@ -47,3 +48,24 @@ void Effect::register_vec3(const std::string &key, float *values)
        params_vec3[key] = values;
 }
 
+// Output convenience uniforms for each parameter.
+// These will be filled in per-frame.
+std::string Effect::output_convenience_uniforms()
+{
+       std::string output = "";
+       for (std::map<std::string, float*>::const_iterator it = params_float.begin();
+            it != params_float.end();
+            ++it) {
+               char buf[256];
+               sprintf(buf, "uniform float PREFIX(%s);\n", it->first.c_str());
+               output.append(buf);
+       }
+       for (std::map<std::string, float*>::const_iterator it = params_vec3.begin();
+            it != params_vec3.end();
+            ++it) {
+               char buf[256];
+               sprintf(buf, "uniform vec3 PREFIX(%s);\n", it->first.c_str());
+               output.append(buf);
+       }
+       return output;
+}
index 623915b..c53a155 100644 (file)
--- a/effect.h
+++ b/effect.h
@@ -18,6 +18,8 @@ public:
        virtual bool needs_srgb_primaries() { return true; }
        virtual bool needs_many_samples() { return false; }
        virtual bool needs_mipmaps() { return false; }
+
+       virtual std::string output_convenience_uniforms();
        virtual std::string output_glsl() = 0;
 
        // Neither of these take ownership.
index 32ee2ce..50fe599 100644 (file)
@@ -1,6 +1,7 @@
 #define GL_GLEXT_PROTOTYPES 1
 
 #include <stdio.h>
+#include <string.h>
 #include <assert.h>
 
 #include <GL/gl.h>
@@ -68,6 +69,47 @@ Effect *EffectChain::add_effect(EffectId effect_id)
        return effect;
 }
 
+// GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
+std::string replace_prefix(const std::string &text, const std::string &prefix)
+{
+       std::string output;
+       size_t start = 0;
+
+       while (start < text.size()) {
+               size_t pos = text.find("PREFIX(", start);
+               if (pos == std::string::npos) {
+                       output.append(text.substr(start, std::string::npos));
+                       break;
+               }
+
+               output.append(text.substr(start, pos - start));
+               output.append(prefix);
+               output.append("_");
+
+               pos += strlen("PREFIX(");
+       
+               // Output stuff until we find the matching ), which we then eat.
+               int depth = 1;
+               size_t end_arg_pos = pos;
+               while (end_arg_pos < text.size()) {
+                       if (text[end_arg_pos] == '(') {
+                               ++depth;
+                       } else if (text[end_arg_pos] == ')') {
+                               --depth;
+                               if (depth == 0) {
+                                       break;
+                               }
+                       }
+                       ++end_arg_pos;
+               }
+               output.append(text.substr(pos, end_arg_pos - pos));
+               ++end_arg_pos;
+               assert(depth == 0);
+               start = end_arg_pos;
+       }
+       return output;
+}
+
 void EffectChain::finalize()
 {
        std::string frag_shader = read_file("header.glsl");
@@ -77,9 +119,9 @@ void EffectChain::finalize()
                sprintf(effect_id, "eff%d", i);
        
                frag_shader += "\n";
-               frag_shader += std::string("#define PREFIX(x) ") + effect_id + "_ ## x\n";
                frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
-               frag_shader += effects[i]->output_glsl();
+               frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
+               frag_shader += replace_prefix(effects[i]->output_glsl(), effect_id);
                frag_shader += "#undef PREFIX\n";
                frag_shader += "#undef FUNCNAME\n";
                frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";