[client] egl: add new downscale filter

client/renderers/EGL/CMakeLists.txt

@@ -63,6 +63,7 @@ build_shaders(
 	shader/ffx_cas.frag
 	shader/ffx_fsr1_easu.frag
 	shader/ffx_fsr1_rcas.frag
+	shader/downscale.frag
 )
 
 make_defines(
@@ -91,6 +92,7 @@ add_library(renderer_EGL STATIC
 	ffx.c
 	filter_ffx_cas.c
 	filter_ffx_fsr1.c
+	filter_downscale.c
 	${EGL_SHADER_OBJS}
 	"${CMAKE_CURRENT_BINARY_DIR}/shader/desktop_rgb.def.h"
 	${PROJECT_TOP}/repos/cimgui/imgui/backends/imgui_impl_opengl3.cpp

client/renderers/EGL/desktop.c

@@ -171,8 +171,9 @@ bool egl_desktopInit(EGL * egl, EGL_Desktop ** desktop_, EGLDisplay * display,
     return false;
   }
 
-  egl_postProcessAdd(desktop->pp, &egl_filterFFXCASOps );
-  egl_postProcessAdd(desktop->pp, &egl_filterFFXFSR1Ops);
+  egl_postProcessAdd(desktop->pp, &egl_filterDownscaleOps);
+  egl_postProcessAdd(desktop->pp, &egl_filterFFXCASOps   );
+  egl_postProcessAdd(desktop->pp, &egl_filterFFXFSR1Ops  );
   return true;
 }
 

client/renderers/EGL/filter_downscale.c

@@ -0,0 +1,263 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2021 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "filter.h"
+#include "framebuffer.h"
+
+#include <math.h>
+
+#include "common/debug.h"
+#include "common/option.h"
+#include "cimgui.h"
+
+#include "basic.vert.h"
+#include "downscale.frag.h"
+
+typedef struct EGL_FilterDownscale
+{
+  EGL_Filter base;
+
+  EGL_Shader * shader;
+  bool         enable;
+  EGL_Uniform  uniform;
+
+  enum EGL_PixelFormat pixFmt;
+  unsigned int width, height;
+  float pixelSize;
+  float vOffset, hOffset;
+  bool prepared;
+
+  EGL_Framebuffer * fb;
+  GLuint            sampler;
+}
+EGL_FilterDownscale;
+
+static void egl_filterDownscaleEarlyInit(void)
+{
+  // doesn't really make sense to have any options for this filter
+  // as it's per title. We need presets to make this nicer to use.
+  static struct Option options[] =
+  {
+    { 0 }
+  };
+
+  option_register(options);
+}
+
+static bool egl_filterDownscaleInit(EGL_Filter ** filter)
+{
+  EGL_FilterDownscale * this = calloc(1, sizeof(*this));
+  if (!this)
+  {
+    DEBUG_ERROR("Failed to allocate ram");
+    return false;
+  }
+
+  if (!egl_shaderInit(&this->shader))
+  {
+    DEBUG_ERROR("Failed to initialize the shader");
+    goto error_this;
+  }
+
+  if (!egl_shaderCompile(this->shader,
+        b_shader_basic_vert    , b_shader_basic_vert_size,
+        b_shader_downscale_frag, b_shader_downscale_frag_size)
+     )
+  {
+    DEBUG_ERROR("Failed to compile the shader");
+    goto error_shader;
+  }
+
+  this->uniform.type = EGL_UNIFORM_TYPE_3F;
+  this->uniform.location =
+    egl_shaderGetUniform(this->shader, "uConfig");
+
+  if (!egl_framebufferInit(&this->fb))
+  {
+    DEBUG_ERROR("Failed to initialize the framebuffer");
+    goto error_shader;
+  }
+
+  glGenSamplers(1, &this->sampler);
+  glSamplerParameteri(this->sampler, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glSamplerParameteri(this->sampler, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glSamplerParameteri(this->sampler, GL_TEXTURE_WRAP_S    , GL_CLAMP_TO_EDGE);
+  glSamplerParameteri(this->sampler, GL_TEXTURE_WRAP_T    , GL_CLAMP_TO_EDGE);
+
+  this->enable    = false;
+  this->pixelSize = 2.0f;
+  this->vOffset   = 0.0f;
+  this->hOffset   = 0.0f;
+
+  *filter = &this->base;
+  return true;
+
+error_shader:
+  egl_shaderFree(&this->shader);
+
+error_this:
+  free(this);
+  return false;
+}
+
+static void egl_filterDownscaleFree(EGL_Filter * filter)
+{
+  EGL_FilterDownscale * this = UPCAST(EGL_FilterDownscale, filter);
+
+  egl_shaderFree(&this->shader);
+  egl_framebufferFree(&this->fb);
+  glDeleteSamplers(1, &this->sampler);
+  free(this);
+}
+
+static bool egl_filterDownscaleImguiConfig(EGL_Filter * filter)
+{
+  EGL_FilterDownscale * this = UPCAST(EGL_FilterDownscale, filter);
+
+  bool redraw = false;
+  bool enable = this->enable;
+
+  igCheckbox("Enable", &enable);
+  if (enable != this->enable)
+  {
+    this->enable = enable;
+    redraw = true;
+  }
+
+  int majorPixelSize = floor(this->pixelSize);
+  int minorPixelSize = (this->pixelSize - majorPixelSize) * 10.0f;
+
+  igSliderInt("Major Pixel Size", &majorPixelSize, 1, 10, NULL, 0);
+  igSliderInt("Minor Pixel Size", &minorPixelSize, 0,  9, NULL, 0);
+
+  float pixelSize = (float)majorPixelSize + (float)minorPixelSize / 10.0f;
+  igText("Pixel Size: %.2f", pixelSize);
+  igText("Resolution: %dx%d", this->width, this->height);
+  if (pixelSize != this->pixelSize)
+  {
+    this->pixelSize = pixelSize;
+    redraw = true;
+  }
+
+  float vOffset = this->vOffset;
+  igSliderFloat("V-Offset", &vOffset, -2, 2, NULL, 0);
+  if (vOffset != this->vOffset)
+  {
+    this->vOffset = vOffset;
+    redraw = true;
+  }
+
+  float hOffset = this->hOffset;
+  igSliderFloat("H-Offset", &hOffset, -2, 2, NULL, 0);
+  if (hOffset != this->hOffset)
+  {
+    this->hOffset = hOffset;
+    redraw = true;
+  }
+
+  if (redraw)
+    this->prepared = false;
+
+  return redraw;
+}
+
+static bool egl_filterDownscaleSetup(EGL_Filter * filter,
+    enum EGL_PixelFormat pixFmt, unsigned int width, unsigned int height)
+{
+  EGL_FilterDownscale * this = UPCAST(EGL_FilterDownscale, filter);
+
+  width  = (float)width  / this->pixelSize;
+  height = (float)height / this->pixelSize;
+
+  if (this->prepared               &&
+      pixFmt       == this->pixFmt &&
+      this->width  == width        &&
+      this->height == height)
+    return this->pixelSize > 1.0f;
+
+  if (!egl_framebufferSetup(this->fb, pixFmt, width, height))
+    return false;
+
+  this->pixFmt   = pixFmt;
+  this->width    = width;
+  this->height   = height;
+  this->prepared = false;
+
+  return this->pixelSize > 1.0f;
+}
+
+static void egl_filterDownscaleGetOutputRes(EGL_Filter * filter,
+    unsigned int *width, unsigned int *height)
+{
+  EGL_FilterDownscale * this = UPCAST(EGL_FilterDownscale, filter);
+  *width  = this->width;
+  *height = this->height;
+}
+
+static bool egl_filterDownscalePrepare(EGL_Filter * filter)
+{
+  EGL_FilterDownscale * this = UPCAST(EGL_FilterDownscale, filter);
+
+  if (!this->enable)
+    return false;
+
+  if (this->prepared)
+    return true;
+
+  this->uniform.f[0] = this->pixelSize;
+  this->uniform.f[1] = this->vOffset;
+  this->uniform.f[2] = this->hOffset;
+  egl_shaderSetUniforms(this->shader, &this->uniform, 1);
+  this->prepared = true;
+
+  return true;
+}
+
+static GLuint egl_filterDownscaleRun(EGL_Filter * filter, EGL_Model * model,
+    GLuint texture)
+{
+  EGL_FilterDownscale * this = UPCAST(EGL_FilterDownscale, filter);
+
+  egl_framebufferBind(this->fb);
+
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_2D, texture);
+  glGenerateMipmap(GL_TEXTURE_2D);
+  glBindSampler(0, this->sampler);
+
+  egl_shaderUse(this->shader);
+  egl_modelRender(model);
+
+  return egl_framebufferGetTexture(this->fb);
+}
+
+EGL_FilterOps egl_filterDownscaleOps =
+{
+  .name         = "Downscaler",
+  .type         = EGL_FILTER_TYPE_DOWNSCALE,
+  .earlyInit    = egl_filterDownscaleEarlyInit,
+  .init         = egl_filterDownscaleInit,
+  .free         = egl_filterDownscaleFree,
+  .imguiConfig  = egl_filterDownscaleImguiConfig,
+  .setup        = egl_filterDownscaleSetup,
+  .getOutputRes = egl_filterDownscaleGetOutputRes,
+  .prepare      = egl_filterDownscalePrepare,
+  .run          = egl_filterDownscaleRun
+};

client/renderers/EGL/filters.h

@@ -20,5 +20,6 @@
 
 #pragma once
 
+extern EGL_FilterOps egl_filterDownscaleOps;
 extern EGL_FilterOps egl_filterFFXCASOps;
 extern EGL_FilterOps egl_filterFFXFSR1Ops;

client/renderers/EGL/postprocess.c

@@ -32,6 +32,7 @@
 
 static const EGL_FilterOps * EGL_Filters[] =
 {
+  &egl_filterDownscaleOps,
   &egl_filterFFXFSR1Ops,
   &egl_filterFFXCASOps
 };

client/renderers/EGL/shader/downscale.frag

@@ -0,0 +1,26 @@
+#version 300 es
+precision mediump float;
+
+in  vec2  fragCoord;
+out vec4  fragColor;
+
+uniform sampler2D texture;
+uniform vec3      uConfig;
+
+void main()
+{
+  float pixelSize = uConfig.x;
+  float vOffset   = uConfig.y;
+  float hOffset   = uConfig.z;
+
+  vec2 inRes  = vec2(textureSize(texture, 0));
+  ivec2 point = ivec2(
+    (floor((fragCoord * inRes) / pixelSize) * pixelSize) +
+    pixelSize / 2.0f
+  );
+
+  point.x += int(pixelSize * hOffset);
+  point.y += int(pixelSize * vOffset);
+
+  fragColor = texelFetch(texture, point, 0);
+}