renderer: optimise shader usage further, split shaders and add more caching (#12992)

* shader: split CM rgba/rgbx into discard ones

make it branchless if we have no discards.

* shader: ensure we dont stall on vbo uv buffer

if we render a new texture before the previous was done gpu wise its
going to stall until done, call glBufferData to orphan the data.
this allows the driver to return a new memory block immediately
if the GPU is still reading from the previous one

* protocols: ensure we reset GL_PACK_ALIGNMENT

reset GL_PACK_ALIGNMENT back to the default initial value of 4

* shader: use unsigned short in VAO

loose a tiny bit of precision but gain massive bandwidth reductions.
use GL_UNSIGNED_SHORT and set it as normalized. clamp and round the UV
for uint16_t in customUv.

* shader: interleave vertex buffers

use std::array for fullverts, use a single interleaved buffer for
position and uv, should in theory improve cache locality. and also remove
the need to have two buffers around.

* shader: revert precision drop

we need the float precision because we might have 1.01 or similiar
floats entering CM shader maths, and rounding/clamping those means the
maths turns out wrong. so revert back to float, sadly higher bandwidth
usage.

* update doColorManagement api

* convert primaries to XYZ on cpu

* remove unused primaries uniform

---------

Co-authored-by: UjinT34 <ujint34@mail.ru>

1 files changed, 14 insertions, 6 deletions

diff --git a/src/render/OpenGL.hpp b/src/render/OpenGL.hpp
index 857cb891..4189e32b 100644
--- a/src/render/OpenGL.hpp
+++ b/src/render/OpenGL.hpp
@@ -35,13 +35,19 @@
 struct gbm_device;
 class CHyprRenderer;
 
-inline const float fullVerts[] = {
-    1, 0, // top right
-    0, 0, // top left
-    1, 1, // bottom right
-    0, 1, // bottom left
+struct SVertex {
+    float x, y; // position
+    float u, v; // uv
 };
-inline const float fanVertsFull[] = {-1.0f, -1.0f, 1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f};
+
+constexpr std::array<SVertex, 4> fullVerts = {{
+    {0.0f, 0.0f, 0.0f, 0.0f}, // top-left
+    {0.0f, 1.0f, 0.0f, 1.0f}, // bottom-left
+    {1.0f, 0.0f, 1.0f, 0.0f}, // top-right
+    {1.0f, 1.0f, 1.0f, 1.0f}, // bottom-right
+}};
+
+inline const float               fanVertsFull[] = {-1.0f, -1.0f, 1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f};
 
 enum eDiscardMode : uint8_t {
     DISCARD_OPAQUE = 1,
@@ -98,7 +104,9 @@ enum ePreparedFragmentShader : uint8_t {
     SH_FRAG_BORDER1,
     SH_FRAG_GLITCH,
     SH_FRAG_CM_RGBA,
+    SH_FRAG_CM_RGBA_DISCARD,
     SH_FRAG_CM_RGBX,
+    SH_FRAG_CM_RGBX_DISCARD,
 
     SH_FRAG_LAST,
 };