1 files changed, 85 insertions, 0 deletions
diff --git a/src/render/jsl.cpp b/src/render/jsl.cpp
new file mode 100644
index 0000000..5bb9347
--- /dev/null
+++ b/src/render/jsl.cpp
@@ -0,0 +1,85 @@
+#include "utils/macros.h"
+#include "jsl.h"
+namespace jin
+{
+namespace render
+{
+    //vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 screen_coords) 
+    static const char* base_f = " "
+        "#version 120              \n"
+        "#define number float      \n"
+        "#define Image sampler2D   \n"
+        "#define Texel texture2D   \n"
+        "#define extern uniform    \n"
+        "uniform sampler2D _tex0_; \n"
+        "%s                        \n"
+        "void main(){              \n"
+        "gl_FragColor = effect(gl_Color, _tex0_, gl_TexCoord[0].xy, gl_FragCoord.xy);\n"
+        "}\0";
+
+    void JSLProgram::init(const char* program)
+    {
+        glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &_max_texture_units);
+
+        char* fs = (char*)alloca(strlen(program) + strlen(base_f));
+        sprintf(fs, base_f, program);
+        GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
+        glShaderSource(fragmentShader, 1, (const GLchar**)&fs, NULL);
+        glCompileShader(fragmentShader);
+
+        pid = glCreateProgram();
+        glAttachShader(pid, fragmentShader);
+        glLinkProgram(pid);
+    }
+
+    shared std::map<std::string, GLint> JSLProgram::_texture_unit_pool;
+    shared GLint JSLProgram::_current_texture_unit = 0;
+    shared GLint JSLProgram::_max_texture_units = 0;
+
+    shared GLint JSLProgram::getTextureUnit(const std::string& name)
+    {
+        std::map<std::string, GLint>::const_iterator it = _texture_unit_pool.find(name);
+
+        if (it != _texture_unit_pool.end())
+            return it->second;
+
+        if (++_current_texture_unit >= _max_texture_units)
+            return 0;
+
+        _texture_unit_pool[name] = _current_texture_unit;
+        return _current_texture_unit;
+    }
+
+    void JSLProgram::use()
+    {
+        glUseProgram(pid); 
+    }
+
+    void JSLProgram::unuse()
+    {
+        glUseProgram(0);
+        
+    }
+
+    void JSLProgram::sendFloat(const char* variable, float number)
+    {
+        int loc = glGetUniformLocation(pid, variable); 
+        glUniform1f(loc, number);
+    }
+
+    void JSLProgram::sendImage(const char*  variable, const Image* image)
+    {
+        GLint texture_unit = getTextureUnit(variable);
+
+        GLint location = glGetUniformLocation(pid, variable);
+
+        glActiveTexture(GL_TEXTURE0 + texture_unit);
+        glBindTexture(GL_TEXTURE_2D, image->getTexture()); // guarantee it gets bound
+        glUniform1i(location, texture_unit);
+
+        // reset texture unit
+        glActiveTexture(GL_TEXTURE0);
+    }
+    
+}
+}