From c51c3b2660ce32ec859cb83df03a50e088e70b32 Mon Sep 17 00:00:00 2001
From: Benjamin Otte <otte@redhat.com>
Date: Sat, 4 Nov 2023 04:13:57 +0100
Subject: [PATCH] gpu: Cache GL state

That way we don't need to setup the textures and program for every
command.
---
 gsk/gpu/gskgpumipmapop.c     |  4 ++--
 gsk/gpu/gskgpuopprivate.h    |  6 ++++++
 gsk/gpu/gskgpushaderop.c     | 30 +++++++++++++++++++++++-------
 gsk/gpu/gskgputypesprivate.h |  1 +
 4 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/gsk/gpu/gskgpumipmapop.c b/gsk/gpu/gskgpumipmapop.c
index 991b532d76..374e6ae199 100644
--- a/gsk/gpu/gskgpumipmapop.c
+++ b/gsk/gpu/gskgpumipmapop.c
@@ -155,10 +155,10 @@ gsk_gpu_mipmap_op_gl_command (GskGpuOp          *op,
 {
   GskGpuMipmapOp *self = (GskGpuMipmapOp *) op;
 
-  /* not sure the ActiveTexture call is needed, but better not
-   * use any random texturing instance */
   glActiveTexture (GL_TEXTURE0);
   gsk_gl_image_bind_texture (GSK_GL_IMAGE (self->image));
+  /* need to reset the images again */
+  state->desc = NULL;
 
   glGenerateMipmap (GL_TEXTURE_2D);
 
diff --git a/gsk/gpu/gskgpuopprivate.h b/gsk/gpu/gskgpuopprivate.h
index 064a592cd7..3bf98710ad 100644
--- a/gsk/gpu/gskgpuopprivate.h
+++ b/gsk/gpu/gskgpuopprivate.h
@@ -23,6 +23,12 @@ typedef struct _GskVulkanCommandState GskVulkanCommandState;
 struct _GskGLCommandState
 {
   gsize flip_y;
+  struct {
+    const GskGpuOpClass *op_class;
+    GskGpuShaderClip clip;
+    gsize n_external;
+  } current_program;
+  GskGLDescriptors *desc;
 };
 
 #ifdef GDK_RENDERING_VULKAN
diff --git a/gsk/gpu/gskgpushaderop.c b/gsk/gpu/gskgpushaderop.c
index 0ed5a0264c..18a69fb379 100644
--- a/gsk/gpu/gskgpushaderop.c
+++ b/gsk/gpu/gskgpushaderop.c
@@ -84,16 +84,32 @@ gsk_gpu_shader_op_gl_command_n (GskGpuOp          *op,
   GskGpuShaderOpClass *shader_op_class = (GskGpuShaderOpClass *) op->op_class;
   GskGLDescriptors *desc;
   GskGpuOp *next;
-  gsize i;
+  gsize i, n_external;
 
   desc = GSK_GL_DESCRIPTORS (self->desc);
-  gsk_gl_frame_use_program (GSK_GL_FRAME (frame),
-                            shader_op_class,
-                            self->clip,
-                            desc ? gsk_gl_descriptors_get_n_external (desc) : 0);
-
   if (desc)
-    gsk_gl_descriptors_use (GSK_GL_DESCRIPTORS (desc));
+    n_external = gsk_gl_descriptors_get_n_external (desc);
+  else
+    n_external = 0;
+
+  if (state->current_program.op_class != op->op_class ||
+      state->current_program.clip != self->clip ||
+      state->current_program.n_external != n_external)
+    {
+      state->current_program.op_class = op->op_class;
+      state->current_program.clip = self->clip;
+      state->current_program.n_external = n_external;
+      gsk_gl_frame_use_program (GSK_GL_FRAME (frame),
+                                shader_op_class,
+                                self->clip,
+                                n_external);
+    }
+
+  if (desc != state->desc && desc)
+    {
+      gsk_gl_descriptors_use (desc);
+      state->desc = desc;
+    }
 
   i = 1;
   for (next = op->next; next && i < 10 * 1000; next = next->next)
diff --git a/gsk/gpu/gskgputypesprivate.h b/gsk/gpu/gskgputypesprivate.h
index 67a1d1bb8e..286b4f2056 100644
--- a/gsk/gpu/gskgputypesprivate.h
+++ b/gsk/gpu/gskgputypesprivate.h
@@ -6,6 +6,7 @@
 
 #define GSK_GPU_PATTERN_STACK_SIZE 16
 
+typedef struct _GskGLDescriptors        GskGLDescriptors;
 typedef struct _GskGpuBuffer            GskGpuBuffer;
 typedef struct _GskGpuDescriptors       GskGpuDescriptors;
 typedef struct _GskGpuDevice            GskGpuDevice;