Make sure our uploaded RGBA textures can deal with being asked for linear gamma.

[nageru] / tweaked_inputs.h

diff --git a/tweaked_inputs.h b/tweaked_inputs.h
index 5478ddee21594d8e708e7b0a00a8b7a667f8ebfb..37c67827fe922f0cc247035729b50bec49e69deb 100644 (file)
--- a/tweaked_inputs.h
+++ b/tweaked_inputs.h
@@ -21,4 +21,57 @@ public:
         bool override_disable_bounce() const override { return true; }
 };
 
+// We use FlatInput with RGBA inputs a few places where we can't tell when
+// uploading the texture whether it needs to be converted from sRGB to linear
+// or not. (FlatInput deals with this if you give it pixels, but we give it
+// already uploaded textures.)
+//
+// If we have GL_EXT_texture_sRGB_decode (very common, as far as I can tell),
+// we can just always upload with the sRGB flag turned on, and then turn it off
+// if not requested; that's sRGBSwitchingFlatInput. If not, we just need to
+// turn off the functionality altogether, which is NonsRGBCapableFlatInput.
+//
+// If you're using NonsRGBCapableFlatInput, upload with GL_RGBA8.
+// If using sRGBSwitchingFlatInput, upload with GL_SRGB8_ALPHA8.
+
+class NonsRGBCapableFlatInput : public movit::FlatInput {
+public:
+       NonsRGBCapableFlatInput(movit::ImageFormat format, movit::MovitPixelFormat pixel_format, GLenum type, unsigned width, unsigned height)
+           : movit::FlatInput(format, pixel_format, type, width, height) {}
+
+       bool can_output_linear_gamma() const override { return false; }
+};
+
+class sRGBSwitchingFlatInput : public movit::FlatInput {
+public:
+       sRGBSwitchingFlatInput(movit::ImageFormat format, movit::MovitPixelFormat pixel_format, GLenum type, unsigned width, unsigned height)
+           : movit::FlatInput(format, pixel_format, type, width, height) {}
+
+       void set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num) override
+       {
+               movit::FlatInput::set_gl_state(glsl_program_num, prefix, sampler_num);
+
+               // This flag is ignored for non-sRGB-uploaded textures, so we can set it
+               // without checking can_output_linear_gamma().
+               glActiveTexture(GL_TEXTURE0 + *sampler_num - 1);
+               if (output_linear_gamma) {
+                       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_SRGB_DECODE_EXT, GL_DECODE_EXT);
+               } else {
+                       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_SRGB_DECODE_EXT, GL_SKIP_DECODE_EXT);
+               }
+       }
+
+       bool set_int(const std::string &key, int value) override
+       {
+               if (key == "output_linear_gamma") {
+                       output_linear_gamma = value;
+               }
+               return movit::FlatInput::set_int(key, value);
+       }
+
+private:
+       int output_linear_gamma = false;
+};
+
+
 #endif  // !defined(_TWEAKED_INPUTS_H)