fixes for premultiplied transparency on image quantities

nmwsharp · Nov 20, 2023 · 783a333 · 783a333
1 parent 2cd38b7
commit 783a333
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Showing 7 changed files with 52 additions and 16 deletions.
diff --git a/include/polyscope/render/opengl/shaders/texture_draw_shaders.h b/include/polyscope/render/opengl/shaders/texture_draw_shaders.h
@@ -32,8 +32,10 @@ extern const ShaderReplacementRule
 extern const ShaderReplacementRule
     TEXTURE_ORIGIN_LOWERLEFT; // sample textures with (0,0) in the lower left, which is the usual openGL rule
 extern const ShaderReplacementRule TEXTURE_SET_TRANSPARENCY; // apply a transparency uniform to the texture
-extern const ShaderReplacementRule TEXTURE_PREMULTIPLY_OUT;  // premultiply color samples
-extern const ShaderReplacementRule TEXTURE_SHADE_COLOR;      // sample a color from a texture and use it for shading
+extern const ShaderReplacementRule
+    TEXTURE_SET_TRANSPARENCY_PREMULTIPLIED;                 // apply a transparency uniform to the texture
+extern const ShaderReplacementRule TEXTURE_PREMULTIPLY_OUT; // premultiply color samples
+extern const ShaderReplacementRule TEXTURE_SHADE_COLOR;     // sample a color from a texture and use it for shading
 extern const ShaderReplacementRule
     TEXTURE_SHADE_COLORALPHA;                               // sample a coloralpha from a texture and use it for shading
 extern const ShaderReplacementRule TEXTURE_PROPAGATE_VALUE; // sample a scalar from a texture and use it for shading

diff --git a/src/color_image_quantity.cpp b/src/color_image_quantity.cpp
@@ -41,9 +41,17 @@ std::string ColorImageQuantity::niceName() { return name + " (color image)"; }
 void ColorImageQuantity::prepareFullscreen() {
 
   // Create the sourceProgram
-  fullscreenProgram = render::engine->requestShader(
-      "TEXTURE_DRAW_PLAIN", {getImageOriginRule(imageOrigin), "TEXTURE_SET_TRANSPARENCY", "INVERSE_TONEMAP"},
-      render::ShaderReplacementDefaults::Process);
+  // clang-format off
+  fullscreenProgram =
+      render::engine->requestShader("TEXTURE_DRAW_PLAIN",
+                                    {
+                                      getImageOriginRule(imageOrigin), 
+                                      getIsPremultiplied() ? "TEXTURE_SET_TRANSPARENCY_PREMULTIPLIED" : "TEXTURE_SET_TRANSPARENCY",
+                                      "INVERSE_TONEMAP",
+                                      getIsPremultiplied() ? "" : "TEXTURE_PREMULTIPLY_OUT"
+                                    },
+                                    render::ShaderReplacementDefaults::Process);
+  // clang-format on
   fullscreenProgram->setAttribute("a_position", render::engine->screenTrianglesCoords());
   // TODO throughout polyscope we discard the shared pointer when adding textures/attributes to programs... should we
   // just track the shared pointer?
@@ -53,11 +61,18 @@ void ColorImageQuantity::prepareFullscreen() {
 void ColorImageQuantity::prepareBillboard() {
 
   // Create the sourceProgram
-  billboardProgram = render::engine->requestShader("TEXTURE_DRAW_PLAIN",
-                                                   {getImageOriginRule(imageOrigin), "TEXTURE_SET_TRANSPARENCY",
-                                                    "TEXTURE_BILLBOARD_FROM_UNIFORMS", "INVERSE_TONEMAP",
-                                                    getIsPremultiplied() ? "" : "TEXTURE_PREMULTIPLY_OUT"},
-                                                   render::ShaderReplacementDefaults::Process);
+  // clang-format off
+  billboardProgram = 
+    render::engine->requestShader("TEXTURE_DRAW_PLAIN",
+                                  {
+                                    getImageOriginRule(imageOrigin), 
+                                    getIsPremultiplied() ? "TEXTURE_SET_TRANSPARENCY_PREMULTIPLIED" : "TEXTURE_SET_TRANSPARENCY",
+                                    "TEXTURE_BILLBOARD_FROM_UNIFORMS", 
+                                    "INVERSE_TONEMAP",
+                                    getIsPremultiplied() ? "" : "TEXTURE_PREMULTIPLY_OUT"
+                                  },
+                                 render::ShaderReplacementDefaults::Process);
+  // clang-format on
   billboardProgram->setAttribute("a_position", render::engine->screenTrianglesCoords());
   billboardProgram->setTextureFromBuffer("t_image", colors.getRenderTextureBuffer().get());
 }

diff --git a/src/render/managed_buffer.cpp b/src/render/managed_buffer.cpp
@@ -591,7 +591,7 @@ template<> ManagedBufferMap<glm::uvec4>&               ManagedBufferMap<glm::uve
 
 std::string typeName(ManagedBufferType type) {
   switch (type) {
-    // clang-format off
+  // clang-format off
     case ManagedBufferType::Float     : return "Float";    
     case ManagedBufferType::Double    : return "Double";   
     case ManagedBufferType::Vec2      : return "Vec2";     

diff --git a/src/render/mock_opengl/mock_gl_engine.cpp b/src/render/mock_opengl/mock_gl_engine.cpp
@@ -1962,6 +1962,7 @@ void MockGLEngine::populateDefaultShadersAndRules() {
   registerShaderRule("TEXTURE_ORIGIN_UPPERLEFT", TEXTURE_ORIGIN_UPPERLEFT);
   registerShaderRule("TEXTURE_ORIGIN_LOWERLEFT", TEXTURE_ORIGIN_LOWERLEFT);
   registerShaderRule("TEXTURE_SET_TRANSPARENCY", TEXTURE_SET_TRANSPARENCY);
+  registerShaderRule("TEXTURE_SET_TRANSPARENCY_PREMULTIPLIED", TEXTURE_SET_TRANSPARENCY_PREMULTIPLIED);
   registerShaderRule("TEXTURE_PREMULTIPLY_OUT", TEXTURE_PREMULTIPLY_OUT);
   registerShaderRule("TEXTURE_SHADE_COLOR", TEXTURE_SHADE_COLOR);
   registerShaderRule("TEXTURE_SHADE_COLORALPHA", TEXTURE_SHADE_COLORALPHA);

diff --git a/src/render/opengl/gl_engine.cpp b/src/render/opengl/gl_engine.cpp
@@ -2730,6 +2730,7 @@ void GLEngine::populateDefaultShadersAndRules() {
   registerShaderRule("TEXTURE_ORIGIN_UPPERLEFT", TEXTURE_ORIGIN_UPPERLEFT);
   registerShaderRule("TEXTURE_ORIGIN_LOWERLEFT", TEXTURE_ORIGIN_LOWERLEFT);
   registerShaderRule("TEXTURE_SET_TRANSPARENCY", TEXTURE_SET_TRANSPARENCY);
+  registerShaderRule("TEXTURE_SET_TRANSPARENCY_PREMULTIPLIED", TEXTURE_SET_TRANSPARENCY_PREMULTIPLIED);
   registerShaderRule("TEXTURE_PREMULTIPLY_OUT", TEXTURE_PREMULTIPLY_OUT);
   registerShaderRule("TEXTURE_SHADE_COLOR", TEXTURE_SHADE_COLOR);
   registerShaderRule("TEXTURE_SHADE_COLORALPHA", TEXTURE_SHADE_COLORALPHA);

diff --git a/src/render/opengl/shaders/texture_draw_shaders.cpp b/src/render/opengl/shaders/texture_draw_shaders.cpp
@@ -621,6 +621,23 @@ const ShaderReplacementRule TEXTURE_SET_TRANSPARENCY(
     /* textures */ {}
 );
 
+const ShaderReplacementRule TEXTURE_SET_TRANSPARENCY_PREMULTIPLIED(
+    /* rule name */ "TEXTURE_SET_TRANSPARENCY_PREMULTIPLIED",
+    { /* replacement sources */
+      {"FRAG_DECLARATIONS", R"(
+          uniform float u_transparency;
+        )" },
+      {"TEXTURE_OUT_ADJUST", R"(
+        textureOut *= u_transparency;
+      )"}
+    },
+    /* uniforms */ {
+        {"u_transparency", RenderDataType::Float},
+    },
+    /* attributes */ {},
+    /* textures */ {}
+);
+
 // remember to use this rule _after_ TEXTURE_SET_TRANSPARENCY
 const ShaderReplacementRule TEXTURE_PREMULTIPLY_OUT(
     /* rule name */ "TEXTURE_PREMULTIPLY_OUT",

diff --git a/src/scalar_image_quantity.cpp b/src/scalar_image_quantity.cpp
@@ -59,11 +59,11 @@ void ScalarImageQuantity::prepareFullscreen() {
 void ScalarImageQuantity::prepareBillboard() {
 
   // Create the sourceProgram
-  billboardProgram =
-      render::engine->requestShader("SCALAR_TEXTURE_COLORMAP",
-                                    this->addScalarRules({getImageOriginRule(imageOrigin), "TEXTURE_SET_TRANSPARENCY",
-                                                          "TEXTURE_BILLBOARD_FROM_UNIFORMS"}),
-                                    render::ShaderReplacementDefaults::Process);
+  billboardProgram = render::engine->requestShader(
+      "SCALAR_TEXTURE_COLORMAP",
+      this->addScalarRules({getImageOriginRule(imageOrigin), "TEXTURE_SET_TRANSPARENCY", "TEXTURE_PREMULTIPLY_OUT",
+                            "TEXTURE_BILLBOARD_FROM_UNIFORMS"}),
+      render::ShaderReplacementDefaults::Process);
   billboardProgram->setAttribute("a_position", render::engine->screenTrianglesCoords());
   billboardProgram->setTextureFromBuffer("t_scalar", values.getRenderTextureBuffer().get());
   billboardProgram->setTextureFromColormap("t_colormap", this->cMap.get());