X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fbackends%2Fopengl%2Fblend_backend.cpp;fp=source%2Fbackends%2Fopengl%2Fblend_backend.cpp;h=44267480bd180ba16fc32fbea6c34add1977fce9;hb=160e9eea29bd10034733d59507fa1bcca36be401;hp=0000000000000000000000000000000000000000;hpb=93448d16e72e38afbaecbccf6fdedd46d6a82a73;p=libs%2Fgl.git

diff --git a/source/backends/opengl/blend_backend.cpp b/source/backends/opengl/blend_backend.cpp
new file mode 100644
index 00000000..44267480
--- /dev/null
+++ b/source/backends/opengl/blend_backend.cpp
@@ -0,0 +1,49 @@
+#include <stdexcept>
+#include <msp/gl/extensions/ext_blend_minmax.h>
+#include <msp/gl/extensions/ext_blend_subtract.h>
+#include "blend.h"
+#include "blend_backend.h"
+#include "gl.h"
+
+using namespace std;
+
+namespace Msp {
+namespace GL {
+
+unsigned get_gl_blend_equation(BlendEquation eq)
+{
+	switch(eq)
+	{
+	case ADD: return GL_FUNC_ADD;
+	case SUBTRACT: return GL_FUNC_SUBTRACT;
+	case REVERSE_SUBTRACT: return GL_FUNC_REVERSE_SUBTRACT;
+	case MIN: return GL_MIN;
+	case MAX: return GL_MAX;
+	default: throw invalid_argument("get_gl_blend_equation");
+	}
+}
+
+unsigned get_gl_blend_factor(BlendFactor factor)
+{
+	switch(factor)
+	{
+	case ZERO: return GL_ZERO;
+	case ONE: return GL_ONE;
+	case SRC_COLOR: return GL_SRC_COLOR;
+	case ONE_MINUS_SRC_COLOR: return GL_ONE_MINUS_SRC_COLOR;
+	case SRC_ALPHA: return GL_SRC_ALPHA;
+	case ONE_MINUS_SRC_ALPHA: return GL_ONE_MINUS_SRC_ALPHA;
+	case DST_COLOR: return GL_DST_COLOR;
+	case ONE_MINUS_DST_COLOR: return GL_ONE_MINUS_DST_COLOR;
+	case DST_ALPHA: return GL_DST_ALPHA;
+	case ONE_MINUS_DST_ALPHA: return GL_ONE_MINUS_DST_ALPHA;
+	case CONSTANT_COLOR: return GL_CONSTANT_COLOR;
+	case ONE_MINUS_CONSTANT_COLOR: return GL_ONE_MINUS_CONSTANT_COLOR;
+	case CONSTANT_ALPHA: return GL_CONSTANT_ALPHA;
+	case ONE_MINUS_CONSTANT_ALPHA: return GL_ONE_MINUS_CONSTANT_ALPHA;
+	default: throw invalid_argument("get_gl_blend_factor");
+	}
+}
+
+} // namespace GL
+} // namespace Msp