Add framebuffer:clear(r,g,b,a) (issue #134).

--HG--
branch : minor

src/modules/graphics/opengl/Framebuffer.cpp

@@ -1,4 +1,5 @@
 #include "Framebuffer.h"
+#include "Graphics.h"
 #include <common/Matrix.h>
 
 #include <cstring> // For memcpy
@@ -233,6 +234,22 @@ namespace opengl
 		current = NULL;
 	}
 
+
+	void Framebuffer::clear(const Color& c)
+	{
+		GLuint previous = 0;
+		if (current != NULL)
+			previous = current->fbo;
+
+		strategy->bindFBO(fbo);
+		glPushAttrib(GL_COLOR_BUFFER_BIT);
+		glClearColor((float)c.r/255.0f, (float)c.g/255.0f, (float)c.b/255.0f, (float)c.a/255.0f);
+		glClear(GL_COLOR_BUFFER_BIT);
+		glPopAttrib();
+
+		strategy->bindFBO(previous);
+	}
+
 	void Framebuffer::draw(float x, float y, float angle, float sx, float sy, float ox, float oy) const
 	{
 		static Matrix t;

src/modules/graphics/opengl/Framebuffer.h

@@ -15,6 +15,8 @@ namespace graphics
 {
 namespace opengl
 {
+	struct Color; // forward declaration for clear
+
 	class Framebuffer : public Drawable, public Volatile
 	{
 	public:
@@ -29,6 +31,8 @@ namespace opengl
 		void startGrab();
 		void stopGrab();
 
+		void clear(const Color& c);
+
 		virtual void draw(float x, float y, float angle, float sx, float sy, float ox, float oy) const;
 		love::image::ImageData * getImageData(love::image::Image * image);
 

src/modules/graphics/opengl/wrap_Framebuffer.cpp

@@ -1,3 +1,4 @@
+#include "Graphics.h"
 #include "wrap_Framebuffer.h"
 
 namespace love
@@ -105,6 +106,40 @@ namespace opengl
 		return 2;
 	}
 
+	int w_Framebuffer_clear(lua_State * L)
+	{
+		Framebuffer * fbo = luax_checkfbo(L, 1);
+		Color c;
+		if (lua_isnoneornil(L, 2)) {
+			c.r = 0;
+			c.g = 0;
+			c.b = 0;
+			c.a = 0;
+		} else if (lua_istable(L, 2)) {
+			lua_pushinteger(L, 1);
+			lua_gettable(L, 2);
+			c.r = (unsigned char)luaL_checkint(L, -1);
+			lua_pushinteger(L, 2);
+			lua_gettable(L, 2);
+			c.g = (unsigned char)luaL_checkint(L, -1);
+			lua_pushinteger(L, 3);
+			lua_gettable(L, 2);
+			c.b = (unsigned char)luaL_checkint(L, -1);
+			lua_pushinteger(L, 4);
+			lua_gettable(L, 2);
+			c.g = (unsigned char)luaL_optint(L, -1, 255);
+			lua_pop(L, 4);
+		} else {
+			c.r = (unsigned char)luaL_checkint(L, 2);
+			c.g = (unsigned char)luaL_checkint(L, 3);
+			c.b = (unsigned char)luaL_checkint(L, 4);
+			c.a = (unsigned char)luaL_optint(L, 5, 255);
+		}
+		fbo->clear(c);
+
+		return 0;
+	}
+
 	static const luaL_Reg functions[] = {
 		{ "renderTo", w_Framebuffer_renderTo },
 		{ "getImageData", w_Framebuffer_getImageData },
@@ -112,6 +147,7 @@ namespace opengl
 		{ "getFilter", w_Framebuffer_getFilter },
 		{ "setWrap", w_Framebuffer_setWrap },
 		{ "getWrap", w_Framebuffer_getWrap },
+		{ "clear", w_Framebuffer_clear },
 		{ 0, 0 }
 	};
 

src/modules/graphics/opengl/wrap_Framebuffer.h

@@ -19,6 +19,7 @@ namespace opengl
 	int w_Framebuffer_getFilter(lua_State * L);
 	int w_Framebuffer_setWrap(lua_State * L);
 	int w_Framebuffer_getWrap(lua_State * L);
+	int w_Framebuffer_clear(lua_State * L);
 	int luaopen_framebuffer(lua_State * L);
 
 } // opengl