From 1416456035a025079e845bc873bb19bc8b557e4a Mon Sep 17 00:00:00 2001
From: fleroviux <fleroviux@gmail.com>
Date: Sun, 18 Jun 2023 01:32:32 +0200
Subject: [PATCH] [GPU] DOT3_RGB(A) modes should remap the operands from [0, 1]
to [-1, +1] range
---
src/core/renderer_gl/renderer_gl.cpp | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/src/core/renderer_gl/renderer_gl.cpp b/src/core/renderer_gl/renderer_gl.cpp
index 42cb07d9..e3c8e12f 100644
--- a/src/core/renderer_gl/renderer_gl.cpp
+++ b/src/core/renderer_gl/renderer_gl.cpp
@@ -64,6 +64,9 @@ const char* fragmentShader = R"(
bool tev_unimplemented_source = false;
+ // OpenGL ES 1.1 reference pages for TEVs (this is what the PICA200 implements):
+ // https://registry.khronos.org/OpenGL-Refpages/es1.1/xhtml/glTexEnv.xml
+
vec4 tev_evaluate_source(int tev_id, int src_id) {
vec4 source = vec4(1.0);
@@ -131,6 +134,10 @@ const char* fragmentShader = R"(
vec4 result = vec4(1.0);
+ // TODO:
+ // - test Dot3 RGBA, particularly what happens when rgb_combine != alpha_combine
+ // - test if alpha_combine can use all the same combine modes as rgb_combine
+
switch (rgb_combine) {
case 0u: result.rgb = source0.rgb; break; // Replace
case 1u: result.rgb = source0.rgb * source1.rgb; break; // Modulate
@@ -138,8 +145,8 @@ const char* fragmentShader = R"(
case 3u: result.rgb = clamp(source0.rgb + source1.rgb - 0.5, vec3(0.0), vec3(1.0)); break; // Add signed
case 4u: result.rgb = mix(source1.rgb, source0.rgb, source2.rgb); break; // Interpolate
case 5u: result.rgb = max(vec3(0.0), source0.rgb - source1.rgb); break; // Subtract
- case 6u: result.rgb = vec3(dot(source0.rgb, source1.rgb)); break; // Dot3 RGB
- case 7u: result.rgb = vec3(dot(source0, source1)); break; // Dot3 RGBA, TODO: not sure if this is correct?
+ case 6u:
+ case 7u: result.rgb = vec3(4.0 * dot(source0.rgb - 0.5 , source1.rgb - 0.5)); break; // Dot3 RGB(A)
case 8u: result.rgb = min(vec3(1.0), source0.rgb * source1.rgb + source2.rgb); break; // Multiply then add
case 9u: result.rgb = min(vec3(1.0), (source0.rgb + source1.rgb) * source2.rgb); break; // Add then multiply
default: break; // TODO: figure out what the undocumented values do
@@ -152,8 +159,7 @@ const char* fragmentShader = R"(
case 3u: result.a = clamp(source0.a + source1.a - 0.5, 0.0, 1.0); break; // Add signed
case 4u: result.a = mix(source1.a, source0.a, source2.a); break; // Interpolate
case 5u: result.a = max(0.0, source0.a - source1.a); break; // Subtract
- case 6u: result.a = dot(source0.rgb, source1.rgb); break; // Dot3 RGB
- case 7u: result.a = dot(source0, source1); break; // Dot3 RGBA, TODO: not sure if this is correct?
+ case 7u: result.a = 4.0 * dot(source0.rgb - 0.5 , source1.rgb - 0.5); break; // Dot3 RGB(A)
case 8u: result.a = min(1.0, source0.a * source1.a + source2.a); break; // Multiply then add
case 9u: result.a = min(1.0, (source0.a + source1.a) * source2.a); break; // Add then multiply
default: break; // TODO: figure out what the undocumented values do