Complete rewrite of extension handling

[libs/gl.git] / source / texturecube.cpp

diff --git a/source/texturecube.cpp b/source/texturecube.cpp
index 4a613a37fc948ffa61789a65d912e8b46685001a..bbe6a6b679fe259915e6710036ed75336634816e 100644 (file)
--- a/source/texturecube.cpp
+++ b/source/texturecube.cpp
@@ -1,35 +1,29 @@
+#include "arb_texture_cube_map.h"
 #include "bindable.h"
 #include "error.h"
-#include "extension.h"
 #include "texturecube.h"
 
 using namespace std;
 
-namespace {
+namespace Msp {
+namespace GL {
 
-// An array to facilitate looping through the cube faces
-Msp::GL::TextureCubeFace faces[6] =
+Vector3 TextureCube::directions[6] =
 {
-       Msp::GL::POSITIVE_X,
-       Msp::GL::NEGATIVE_X,
-       Msp::GL::POSITIVE_Y,
-       Msp::GL::NEGATIVE_Y,
-       Msp::GL::POSITIVE_Z,
-       Msp::GL::NEGATIVE_Z
+       Vector3(1, 0, 0),
+       Vector3(-1, 0, 0),
+       Vector3(0, 1, 0),
+       Vector3(0, -1, 0),
+       Vector3(0, 0, 1),
+       Vector3(0, 0, -1)
 };
 
-}
-
-
-namespace Msp {
-namespace GL {
-
 TextureCube::TextureCube():
        Texture(GL_TEXTURE_CUBE_MAP),
        size(0),
        allocated(0)
 {
-       static RequireVersion _ver(1, 3);
+       static Require _req(ARB_texture_cube_map);
 }
 
 void TextureCube::storage(PixelFormat fmt, unsigned sz)
@@ -49,7 +43,7 @@ void TextureCube::allocate(unsigned level)
                return;
 
        for(unsigned i=0; i<6; ++i)
-               image(faces[i], level, get_base_pixelformat(ifmt), UNSIGNED_BYTE, 0);
+               image(enumerate_faces(i), level, get_base_pixelformat(ifmt), UNSIGNED_BYTE, 0);
 }
 
 void TextureCube::image(TextureCubeFace face, unsigned level, PixelFormat fmt, DataType type, const void *data)
@@ -78,5 +72,71 @@ unsigned TextureCube::get_level_size(unsigned level)
        return size>>level;
 }
 
+TextureCubeFace TextureCube::enumerate_faces(unsigned i)
+{
+       switch(i)
+       {
+       case 0: return POSITIVE_X;
+       case 1: return NEGATIVE_X;
+       case 2: return POSITIVE_Y;
+       case 3: return NEGATIVE_Y;
+       case 4: return POSITIVE_Z;
+       case 5: return NEGATIVE_Z;
+       default: throw out_of_range("TextureCube::enumerate_faces");
+       }
+}
+
+const Vector3 &TextureCube::get_face_direction(TextureCubeFace face)
+{
+       switch(face)
+       {
+       case POSITIVE_X: return directions[0];
+       case NEGATIVE_X: return directions[1];
+       case POSITIVE_Y: return directions[2];
+       case NEGATIVE_Y: return directions[3];
+       case POSITIVE_Z: return directions[4];
+       case NEGATIVE_Z: return directions[5];
+       default: throw invalid_argument("TextureCube::get_face_direction");
+       }
+}
+
+const Vector3 &TextureCube::get_s_direction(TextureCubeFace face)
+{
+       switch(face)
+       {
+       case POSITIVE_X: return directions[5];
+       case NEGATIVE_X: return directions[4];
+       case POSITIVE_Y: return directions[0];
+       case NEGATIVE_Y: return directions[0];
+       case POSITIVE_Z: return directions[0];
+       case NEGATIVE_Z: return directions[1];
+       default: throw invalid_argument("TextureCube::get_s_direction");
+       }
+}
+
+const Vector3 &TextureCube::get_t_direction(TextureCubeFace face)
+{
+       switch(face)
+       {
+       case POSITIVE_X: return directions[3];
+       case NEGATIVE_X: return directions[3];
+       case POSITIVE_Y: return directions[4];
+       case NEGATIVE_Y: return directions[5];
+       case POSITIVE_Z: return directions[3];
+       case NEGATIVE_Z: return directions[3];
+       default: throw invalid_argument("TextureCube::get_t_direction");
+       }
+}
+
+Vector3 TextureCube::get_texel_direction(TextureCubeFace face, unsigned u, unsigned v)
+{
+       float s = (u+0.5f)*2.0f/size-1.0f;
+       float t = (v+0.5f)*2.0f/size-1.0f;
+       const Vector3 &fv = get_face_direction(face);
+       const Vector3 &sv = get_s_direction(face);
+       const Vector3 &tv = get_t_direction(face);
+       return Vector3(fv.x+s*sv.x, fv.y+t*tv.y, fv.z+s*sv.z+t*tv.z);
+}
+
 } // namespace GL
 } // namespace Msp