GPUMaterial: Texture Node: support for nearest (closest) filtering method

Add placeholder for cubic and smart filtering for now.

2 files changed, 95 insertions, 11 deletions

diff --git a/source/blender/gpu/shaders/gpu_shader_material.glsl b/source/blender/gpu/shaders/gpu_shader_material.glsl
index 4b376160105..7f2475f0aab 100644
--- a/source/blender/gpu/shaders/gpu_shader_material.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_material.glsl
@@ -1798,13 +1798,31 @@ void node_tex_environment_empty(vec3 co, out vec4 color)
 	color = vec4(1.0, 0.0, 1.0, 1.0);
 }
 
-void node_tex_image(vec3 co, sampler2D ima, out vec4 color, out float alpha)
+void node_tex_image_linear(vec3 co, sampler2D ima, out vec4 color, out float alpha)
 {
 	color = texture(ima, co.xy);
 	alpha = color.a;
 }
 
-void tex_box_sample(vec3 texco,
+void node_tex_image_nearest(vec3 co, sampler2D ima, out vec4 color, out float alpha)
+{
+	ivec2 pix = ivec2(co.xy * textureSize(ima, 0).xy);
+	color = texelFetch(ima, pix, 0);
+	alpha = color.a;
+}
+
+void node_tex_image_cubic(vec3 co, sampler2D ima, out vec4 color, out float alpha)
+{
+	node_tex_image_linear(co, ima, color, alpha);
+}
+
+void node_tex_image_smart(vec3 co, sampler2D ima, out vec4 color, out float alpha)
+{
+	/* use cubic for now */
+	node_tex_image_cubic(co, ima, color, alpha);
+}
+
+void tex_box_sample_linear(vec3 texco,
                     vec3 N,
                     sampler2D ima,
                     out vec4 color1,
@@ -1831,6 +1849,56 @@ void tex_box_sample(vec3 texco,
 	color3 = texture(ima, uv);
 }
 
+void tex_box_sample_nearest(vec3 texco,
+                    vec3 N,
+                    sampler2D ima,
+                    out vec4 color1,
+                    out vec4 color2,
+                    out vec4 color3)
+{
+	/* X projection */
+	vec2 uv = texco.yz;
+	if (N.x < 0.0) {
+		uv.x = 1.0 - uv.x;
+	}
+	ivec2 pix = ivec2(uv.xy * textureSize(ima, 0).xy);
+	color1 = texelFetch(ima, pix, 0);
+	/* Y projection */
+	uv = texco.xz;
+	if (N.y > 0.0) {
+		uv.x = 1.0 - uv.x;
+	}
+	pix = ivec2(uv.xy * textureSize(ima, 0).xy);
+	color2 = texelFetch(ima, pix, 0);
+	/* Z projection */
+	uv = texco.yx;
+	if (N.z > 0.0) {
+		uv.x = 1.0 - uv.x;
+	}
+	pix = ivec2(uv.xy * textureSize(ima, 0).xy);
+	color3 = texelFetch(ima, pix, 0);
+}
+
+void tex_box_sample_cubic(vec3 texco,
+                    vec3 N,
+                    sampler2D ima,
+                    out vec4 color1,
+                    out vec4 color2,
+                    out vec4 color3)
+{
+	tex_box_sample_linear(texco, N, ima, color1, color2, color3);
+}
+
+void tex_box_sample_smart(vec3 texco,
+                    vec3 N,
+                    sampler2D ima,
+                    out vec4 color1,
+                    out vec4 color2,
+                    out vec4 color3)
+{
+	tex_box_sample_cubic(texco, N, ima, color1, color2, color3);
+}
+
 void node_tex_image_box(vec3 texco,
                         vec3 N,
                         vec4 color1,
diff --git a/source/blender/nodes/shader/nodes/node_shader_tex_image.c b/source/blender/nodes/shader/nodes/node_shader_tex_image.c
index 20753445aa6..9782df2638f 100644
--- a/source/blender/nodes/shader/nodes/node_shader_tex_image.c
+++ b/source/blender/nodes/shader/nodes/node_shader_tex_image.c
@@ -55,9 +55,25 @@ static void node_shader_init_tex_image(bNodeTree *UNUSED(ntree), bNode *node)
 
 static int node_shader_gpu_tex_image(GPUMaterial *mat, bNode *node, bNodeExecData *UNUSED(execdata), GPUNodeStack *in, GPUNodeStack *out)
 {
+	static const char *names[] = {
+	    "node_tex_image_linear",
+	    "node_tex_image_nearest",
+	    "node_tex_image_cubic",
+	    "node_tex_image_smart"
+	};
+	static const char *names_box[] = {
+	    "tex_box_sample_linear",
+	    "tex_box_sample_nearest",
+	    "tex_box_sample_cubic",
+	    "tex_box_sample_smart"
+	};
+
 	Image *ima = (Image *)node->id;
 	ImageUser *iuser = NULL;
 	NodeTexImage *tex = node->storage;
+	const char *gpu_node_name = (tex->projection == SHD_PROJ_BOX)
+	                             ? names_box[tex->interpolation]
+	                             : names[tex->interpolation];
 	bool do_color_correction = false;
 
 	GPUNodeLink *norm, *col1, *col2, *col3;
@@ -84,7 +100,7 @@ static int node_shader_gpu_tex_image(GPUMaterial *mat, bNode *node, bNodeExecDat
 
 	switch (tex->projection) {
 		case SHD_PROJ_FLAT:
-			GPU_stack_link(mat, node, "node_tex_image", in, out, GPU_image(ima, iuser, isdata));
+			GPU_stack_link(mat, node, gpu_node_name, in, out, GPU_image(ima, iuser, isdata));
 			break;
 		case SHD_PROJ_BOX:
 			GPU_link(mat, "direction_transform_m4v3", GPU_builtin(GPU_VIEW_NORMAL),
@@ -93,12 +109,12 @@ static int node_shader_gpu_tex_image(GPUMaterial *mat, bNode *node, bNodeExecDat
 			GPU_link(mat, "direction_transform_m4v3", norm,
 			                                          GPU_builtin(GPU_INVERSE_OBJECT_MATRIX),
 			                                          &norm);
-			GPU_link(mat, "tex_box_sample", in[0].link,
-			                                norm,
-			                                GPU_image(ima, iuser, isdata),
-			                                &col1,
-			                                &col2,
-			                                &col3);
+			GPU_link(mat, gpu_node_name, in[0].link,
+			                             norm,
+			                             GPU_image(ima, iuser, isdata),
+			                             &col1,
+			                             &col2,
+			                             &col3);
 			if (do_color_correction) {
 				GPU_link(mat, "srgb_to_linearrgb", col1, &col1);
 				GPU_link(mat, "srgb_to_linearrgb", col2, &col2);
@@ -115,12 +131,12 @@ static int node_shader_gpu_tex_image(GPUMaterial *mat, bNode *node, bNodeExecDat
 		case SHD_PROJ_SPHERE:
 			GPU_link(mat, "point_texco_remap_square", in[0].link, &in[0].link);
 			GPU_link(mat, "point_map_to_sphere", in[0].link, &in[0].link);
-			GPU_stack_link(mat, node, "node_tex_image", in, out, GPU_image(ima, iuser, isdata));
+			GPU_stack_link(mat, node, gpu_node_name, in, out, GPU_image(ima, iuser, isdata));
 			break;
 		case SHD_PROJ_TUBE:
 			GPU_link(mat, "point_texco_remap_square", in[0].link, &in[0].link);
 			GPU_link(mat, "point_map_to_tube", in[0].link, &in[0].link);
-			GPU_stack_link(mat, node, "node_tex_image", in, out, GPU_image(ima, iuser, isdata));
+			GPU_stack_link(mat, node, gpu_node_name, in, out, GPU_image(ima, iuser, isdata));
 			break;
 	}