X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=sor.vert;h=c68b1db922e636bbea64b024d2b6dc0dfa12dc38;hb=0c3bfa8f2fb956efce124dea05e006231603c333;hp=201578c94401dd256ba5cc5c8a95931880b3121d;hpb=670611b5a707fb8dcebf60fcfcd0930545d14875;p=nageru

diff --git a/sor.vert b/sor.vert
index 201578c..c68b1db 100644
--- a/sor.vert
+++ b/sor.vert
@@ -1,10 +1,14 @@
 #version 450 core
+#extension GL_ARB_shader_viewport_layer_array : require
 
-in vec2 position;
-out vec2 tc;
+layout(location=0) in vec2 position;
+out vec3 tc, tc_left, tc_down;
+out vec3 equation_tc_assuming_left, equation_tc_assuming_right;
+out float element_x_idx;
 out float element_sum_idx;
 
-uniform sampler2D diff_flow_tex;
+uniform sampler2DArray diff_flow_tex, diffusivity_tex;
+uniform usampler2DArray equation_red_tex;
 
 void main()
 {
@@ -15,8 +19,25 @@ void main()
 	//   0.000  0.000 -2.000 -1.000
 	//   0.000  0.000  0.000  1.000
 	gl_Position = vec4(2.0 * position.x - 1.0, 2.0 * position.y - 1.0, -1.0, 1.0);
-	tc = position;
+	gl_Layer = gl_InstanceID;
 
-	vec2 element_idx = position * textureSize(diff_flow_tex, 0) - 0.5;
+	tc = vec3(position, gl_InstanceID);
+	tc_left = vec3(tc.x - 0.5f / textureSize(diffusivity_tex, 0).x, tc.y, gl_InstanceID);
+	tc_down = vec3(tc.x, tc.y - 0.5f / textureSize(diffusivity_tex, 0).y, gl_InstanceID);
+
+	// The equation textures have half the horizontal width, so we need to adjust the texel centers.
+	// It becomes extra tricky since the SOR texture might be of odd size, and then
+	// the equation texture is not exactly half the size.
+	vec2 element_idx = position * textureSize(diff_flow_tex, 0).xy - 0.5f;
+	float equation_texel_number_assuming_left = element_idx.x / 2.0f;
+	float equation_texel_number_assuming_right = (element_idx.x - 1.0f) / 2.0f;
+	equation_tc_assuming_left.x = (equation_texel_number_assuming_left + 0.5f) / textureSize(equation_red_tex, 0).x;
+	equation_tc_assuming_right.x = (equation_texel_number_assuming_right + 0.5f) / textureSize(equation_red_tex, 0).x;
+	equation_tc_assuming_left.y = tc.y;
+	equation_tc_assuming_right.y = tc.y;
+	equation_tc_assuming_left.z = gl_InstanceID;
+	equation_tc_assuming_right.z = gl_InstanceID;
+
+	element_x_idx = element_idx.x;
 	element_sum_idx = element_idx.x + element_idx.y;
 }