[Bf-blender-cvs] [054923c8607] master: GPUMaterial: Rework/simplify environment texture filtering

[Clément Foucault]

Commit: 054923c8607c804a717cb5bb8ef15c0d4b151df3
Author: Clément Foucault
Date:   Wed Jun 3 14:59:49 2020 +0200
Branches: master
https://developer.blender.org/rB054923c8607c804a717cb5bb8ef15c0d4b151df3

GPUMaterial: Rework/simplify environment texture filtering

This use the latest GPUTexture change to use the sampler state to avoid
the pole issues instead of using GLSL hacks.

===================================================================

M	source/blender/gpu/shaders/material/gpu_shader_material_tex_environment.glsl
M	source/blender/gpu/shaders/material/gpu_shader_material_tex_image.glsl
M	source/blender/nodes/shader/nodes/node_shader_tex_environment.c

===================================================================

diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_tex_environment.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_tex_environment.glsl
index 9bd36f8a757..20a65f23c05 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_tex_environment.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_tex_environment.glsl
@@ -15,16 +15,11 @@ void node_tex_environment_texco(vec3 viewvec, out vec3 worldvec)
 #endif
 }
 
-void node_tex_environment_equirectangular(vec3 co, float clamp_size, sampler2D ima, out vec3 uv)
+void node_tex_environment_equirectangular(vec3 co, out vec3 uv)
 {
   vec3 nco = normalize(co);
   uv.x = -atan(nco.y, nco.x) / (2.0 * M_PI) + 0.5;
   uv.y = atan(nco.z, hypot(nco.x, nco.y)) / M_PI + 0.5;
-
-  /* Fix pole bleeding */
-  float half_height = clamp_size / float(textureSize(ima, 0).y);
-  uv.y = clamp(uv.y, half_height, 1.0 - half_height);
-  uv.z = 0.0;
 }
 
 void node_tex_environment_mirror_ball(vec3 co, out vec3 uv)
diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_tex_image.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_tex_image.glsl
index c39bec8ac64..3a9fc49e8b8 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_tex_image.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_tex_image.glsl
@@ -54,19 +54,6 @@ void node_tex_image_linear(vec3 co, sampler2D ima, out vec4 color, out float alp
   alpha = color.a;
 }
 
-void node_tex_image_linear_no_mip(vec3 co, sampler2D ima, out vec4 color, out float alpha)
-{
-  color = safe_color(textureLod(ima, co.xy, 0.0));
-  alpha = color.a;
-}
-
-void node_tex_image_nearest(vec3 co, sampler2D ima, out vec4 color, out float alpha)
-{
-  ivec2 pix = ivec2(fract(co.xy) * textureSize(ima, 0).xy);
-  color = safe_color(texelFetch(ima, pix, 0));
-  alpha = color.a;
-}
-
 /** \param f: Signed distance to texel center. */
 void cubic_bspline_coefs(vec2 f, out vec2 w0, out vec2 w1, out vec2 w2, out vec2 w3)
 {
diff --git a/source/blender/nodes/shader/nodes/node_shader_tex_environment.c b/source/blender/nodes/shader/nodes/node_shader_tex_environment.c
index a62c2ee22b2..0cf4b51f307 100644
--- a/source/blender/nodes/shader/nodes/node_shader_tex_environment.c
+++ b/source/blender/nodes/shader/nodes/node_shader_tex_environment.c
@@ -19,6 +19,8 @@
 
 #include "../node_shader_util.h"
 
+#include "GPU_draw.h"
+
 /* **************** OUTPUT ******************** */
 
 static bNodeSocketTemplate sh_node_tex_environment_in[] = {
@@ -56,7 +58,10 @@ static int node_shader_gpu_tex_environment(GPUMaterial *mat,
   bNode *node_original = node->original ? node->original : node;
   NodeTexImage *tex_original = node_original->storage;
   ImageUser *iuser = &tex_original->iuser;
-  eGPUSamplerState sampler_state = GPU_SAMPLER_MAX;
+  eGPUSamplerState sampler = GPU_SAMPLER_REPEAT | GPU_SAMPLER_ANISO | GPU_SAMPLER_FILTER;
+  if (GPU_get_mipmap()) {
+    sampler |= GPU_SAMPLER_MIPMAP;
+  }
 
   GPUNodeLink *outalpha;
 
@@ -73,49 +78,41 @@ static int node_shader_gpu_tex_environment(GPUMaterial *mat,
 
   /* Compute texture coordinate. */
   if (tex->projection == SHD_PROJ_EQUIRECTANGULAR) {
-    /* To fix pole issue we clamp the v coordinate. The clamp value depends on the filter size. */
-    float clamp_size = (ELEM(tex->interpolation, SHD_INTERP_CUBIC, SHD_INTERP_SMART)) ? 1.5 : 0.5;
-    GPU_link(mat,
-             "node_tex_environment_equirectangular",
-             in[0].link,
-             GPU_constant(&clamp_size),
-             GPU_image(mat, ima, iuser, sampler_state),
-             &in[0].link);
+    GPU_link(mat, "node_tex_environment_equirectangular", in[0].link, &in[0].link);
+    /* To fix pole issue we clamp the v coordinate. */
+    sampler &= ~GPU_SAMPLER_REPEAT_T;
+    /* Force the highest mipmap and don't do anisotropic filtering.
+     * This is to fix the artifact caused by derivatives discontinuity. */
+    sampler &= ~(GPU_SAMPLER_MIPMAP | GPU_SAMPLER_ANISO);
   }
   else {
     GPU_link(mat, "node_tex_environment_mirror_ball", in[0].link, &in[0].link);
+    /* Fix pole issue. */
+    sampler &= ~GPU_SAMPLER_REPEAT;
   }
 
-  /* Sample texture with correct interpolation. */
+  const char *gpufunc;
+  static const char *names[] = {
+      "node_tex_image_linear",
+      "node_tex_image_cubic",
+  };
+
   switch (tex->interpolation) {
     case SHD_INTERP_LINEAR:
-      /* Force the highest mipmap and don't do anisotropic filtering.
-       * This is to fix the artifact caused by derivatives discontinuity. */
-      GPU_link(mat,
-               "node_tex_image_linear_no_mip",
-               in[0].link,
-               GPU_image(mat, ima, iuser, sampler_state),
-               &out[0].link,
-               &outalpha);
+      gpufunc = names[0];
       break;
     case SHD_INTERP_CLOSEST:
-      GPU_link(mat,
-               "node_tex_image_nearest",
-               in[0].link,
-               GPU_image(mat, ima, iuser, sampler_state),
-               &out[0].link,
-               &outalpha);
+      sampler &= ~(GPU_SAMPLER_FILTER | GPU_SAMPLER_MIPMAP);
+      gpufunc = names[0];
       break;
     default:
-      GPU_link(mat,
-               "node_tex_image_cubic",
-               in[0].link,
-               GPU_image(mat, ima, iuser, sampler_state),
-               &out[0].link,
-               &outalpha);
+      gpufunc = names[1];
       break;
   }
 
+  /* Sample texture with correct interpolation. */
+  GPU_link(mat, gpufunc, in[0].link, GPU_image(mat, ima, iuser, sampler), &out[0].link, &outalpha);
+
   if (out[0].hasoutput) {
     if (ELEM(ima->alpha_mode, IMA_ALPHA_IGNORE, IMA_ALPHA_CHANNEL_PACKED) ||
         IMB_colormanagement_space_name_is_data(ima->colorspace_settings.name)) {