Move render target texture parameters to renderer gl

docs/modernization/build-inventory.md

@@ -130,13 +130,15 @@ Known local toolchain state:
   upload-type mapping used by legacy `Texture2D` and `RTT` creation. It also
   validates image channel-count to OpenGL texture format mapping, including
   invalid channel counts rejected by `Texture2D::create(Image)`, and
-  framebuffer status naming used by `RTT` diagnostics. It also validates
-  Shape index-type and fill/stroke primitive-mode mapping used by the legacy
-  mesh draw path, plus the PanoPainter cube-face to OpenGL texture-target
-  mapping used by `TextureCube`. The PanoPainter shader attribute binding
-  catalog used by legacy `Shader` creation also lives here. It also owns the
-  PanoPainter shader uniform catalog and legacy hash mapping used by `Shader`
-  active-uniform discovery and the uniform uniqueness check.
+  framebuffer status naming used by `RTT` diagnostics. It also owns and
+  validates the default linear clamp-to-edge render-target texture parameters
+  used by `RTT::create`. It also validates Shape index-type and fill/stroke
+  primitive-mode mapping used by the legacy mesh draw path, plus the
+  PanoPainter cube-face to OpenGL texture-target mapping used by `TextureCube`.
+  The PanoPainter shader attribute binding catalog used by legacy `Shader`
+  creation also lives here. It also owns the PanoPainter shader uniform catalog
+  and legacy hash mapping used by `Shader` active-uniform discovery and the
+  uniform uniqueness check.
 - `windows-msvc-vcpkg-headless` validates manifest install/configure/build/test
   for the current headless component matrix; see DEBT-0007 for remaining app
   and platform triplet migration.

docs/modernization/roadmap.md

@@ -390,11 +390,13 @@ OpenGL capability detection for framebuffer fetch, map-buffer alignment, and
 float texture support. It also owns the OpenGL texture upload-type mapping used
 by legacy `Texture2D` and `RTT` creation, plus image channel-count to texture
 format mapping for `Texture2D` image uploads and framebuffer status naming for
-`RTT` diagnostics. Mesh index-type and primitive-mode decisions used by legacy
-`Shape` drawing and the PanoPainter cube-face to OpenGL texture-target mapping
-used by `TextureCube` also live in `pp_renderer_gl`. The legacy app delegates
-extension, upload-format, framebuffer diagnostic, mesh draw-mode, and cube-face
-texture-target interpretation to that backend library. The PanoPainter shader attribute
+`RTT` diagnostics. The default render-target texture parameters used by
+`RTT::create` also live in `pp_renderer_gl`. Mesh index-type and primitive-mode
+decisions used by legacy `Shape` drawing and the PanoPainter cube-face to
+OpenGL texture-target mapping used by `TextureCube` also live in
+`pp_renderer_gl`. The legacy app delegates extension, upload-format,
+framebuffer diagnostic, render-target texture parameter, mesh draw-mode, and
+cube-face texture-target interpretation to that backend library. The PanoPainter shader attribute
 binding catalog also lives in `pp_renderer_gl` and is consumed by legacy
 `Shader` creation. Shader uniform hashing, catalog validation, active-uniform
 mapping, and the legacy uniform uniqueness check now delegate to
@@ -641,11 +643,12 @@ Results:
   WebGL exclusion behavior, upload types for RGBA8/RGBA16F/RGBA32F internal
   formats, image channel-count format mapping including invalid counts, and
   framebuffer status names, plus Shape index-type and fill/stroke primitive
-  mode mapping and PanoPainter cube-face texture-target order. Shader attribute
-  binding catalog validation covers the current `pos`, `uvs`, `uvs2`, `col`,
-  and `nor` bindings and rejects empty, unnamed, null-name, and duplicate-name
-  catalogs while preserving legacy shared locations. Shader uniform catalog
-  validation covers the 43 legacy uniform
+  mode mapping, PanoPainter cube-face texture-target order, and the linear
+  clamp-to-edge render-target texture parameter set used by `RTT::create`.
+  Shader attribute binding catalog validation covers the current `pos`, `uvs`,
+  `uvs2`, `col`, and `nor` bindings and rejects empty, unnamed, null-name, and
+  duplicate-name catalogs while preserving legacy shared locations. Shader
+  uniform catalog validation covers the 43 legacy uniform
   names used by `Shader`, preserves the legacy hash ids, and rejects empty,
   unnamed, null-name, mismatched-hash, and duplicate-name catalogs.
 - PowerShell analyze automation returns JSON summaries and includes the shader

src/renderer_gl/opengl_capabilities.cpp

@@ -38,6 +38,12 @@ constexpr std::uint32_t gl_texture_cube_map_positive_y = 0x8517U;
 constexpr std::uint32_t gl_texture_cube_map_negative_y = 0x8518U;
 constexpr std::uint32_t gl_texture_cube_map_positive_z = 0x8519U;
 constexpr std::uint32_t gl_texture_cube_map_negative_z = 0x851AU;
+constexpr std::uint32_t gl_linear = 0x2601U;
+constexpr std::uint32_t gl_texture_mag_filter = 0x2800U;
+constexpr std::uint32_t gl_texture_min_filter = 0x2801U;
+constexpr std::uint32_t gl_texture_wrap_s = 0x2802U;
+constexpr std::uint32_t gl_texture_wrap_t = 0x2803U;
+constexpr std::uint32_t gl_clamp_to_edge = 0x812FU;
 
 [[nodiscard]] bool contains(std::string_view text, std::string_view needle) noexcept
 {
@@ -195,4 +201,16 @@ std::uint32_t cube_face_texture_target(std::uint32_t face_index) noexcept
     return targets[face_index];
 }
 
+std::span<const OpenGlTextureParameter> default_render_target_texture_parameters() noexcept
+{
+    static constexpr std::array<OpenGlTextureParameter, 4> parameters {
+        OpenGlTextureParameter { .name = gl_texture_mag_filter, .value = gl_linear },
+        OpenGlTextureParameter { .name = gl_texture_min_filter, .value = gl_linear },
+        OpenGlTextureParameter { .name = gl_texture_wrap_s, .value = gl_clamp_to_edge },
+        OpenGlTextureParameter { .name = gl_texture_wrap_t, .value = gl_clamp_to_edge },
+    };
+
+    return parameters;
+}
+
 }

src/renderer_gl/opengl_capabilities.h

@@ -26,6 +26,11 @@ struct OpenGlPixelFormat {
     std::uint32_t channel_count = 0;
 };
 
+struct OpenGlTextureParameter {
+    std::uint32_t name = 0;
+    std::uint32_t value = 0;
+};
+
 [[nodiscard]] OpenGlCapabilities detect_opengl_capabilities(
     std::span<const std::string_view> extensions,
     OpenGlRuntime runtime) noexcept;
@@ -38,5 +43,6 @@ struct OpenGlPixelFormat {
 [[nodiscard]] std::uint32_t primitive_mode_for_stroke_count(std::uint32_t vertex_or_index_count) noexcept;
 [[nodiscard]] std::span<const std::uint32_t> panopainter_cube_face_texture_targets() noexcept;
 [[nodiscard]] std::uint32_t cube_face_texture_target(std::uint32_t face_index) noexcept;
+[[nodiscard]] std::span<const OpenGlTextureParameter> default_render_target_texture_parameters() noexcept;
 
 }

src/rtt.cpp

@@ -213,10 +213,13 @@ bool RTT::create(int width, int height, int tex/* = -1*/, GLint internal_format,
         glBindTexture(GL_TEXTURE_2D, texID);
         if (tex == -1)
             glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, GL_RGBA, ifmt, 0);
-        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+        for (const auto parameter : pp::renderer::gl::default_render_target_texture_parameters())
+        {
+            glTexParameterf(
+                GL_TEXTURE_2D,
+                static_cast<GLenum>(parameter.name),
+                static_cast<GLfloat>(parameter.value));
+        }
         glBindTexture(GL_TEXTURE_2D, 0);
 
         // Create a renderbuffer object to store depth info

tests/renderer_gl/capabilities_tests.cpp

@@ -174,6 +174,21 @@ void maps_panopainter_cube_faces_to_texture_targets(pp::tests::Harness& h)
     PP_EXPECT(h, pp::renderer::gl::cube_face_texture_target(6U) == 0U);
 }
 
+void exposes_default_render_target_texture_parameters(pp::tests::Harness& h)
+{
+    const auto parameters = pp::renderer::gl::default_render_target_texture_parameters();
+
+    PP_EXPECT(h, parameters.size() == 4U);
+    PP_EXPECT(h, parameters[0].name == 0x2800U);
+    PP_EXPECT(h, parameters[0].value == 0x2601U);
+    PP_EXPECT(h, parameters[1].name == 0x2801U);
+    PP_EXPECT(h, parameters[1].value == 0x2601U);
+    PP_EXPECT(h, parameters[2].name == 0x2802U);
+    PP_EXPECT(h, parameters[2].value == 0x812FU);
+    PP_EXPECT(h, parameters[3].name == 0x2803U);
+    PP_EXPECT(h, parameters[3].value == 0x812FU);
+}
+
 void exposes_shader_attribute_binding_catalog(pp::tests::Harness& h)
 {
     const auto bindings = pp::renderer::gl::panopainter_shader_attribute_bindings();
@@ -277,6 +292,7 @@ int main()
     harness.run("names_framebuffer_status_codes", names_framebuffer_status_codes);
     harness.run("maps_shape_index_and_primitive_modes", maps_shape_index_and_primitive_modes);
     harness.run("maps_panopainter_cube_faces_to_texture_targets", maps_panopainter_cube_faces_to_texture_targets);
+    harness.run("exposes_default_render_target_texture_parameters", exposes_default_render_target_texture_parameters);
     harness.run("exposes_shader_attribute_binding_catalog", exposes_shader_attribute_binding_catalog);
     harness.run("rejects_invalid_shader_attribute_binding_catalogs", rejects_invalid_shader_attribute_binding_catalogs);
     harness.run("exposes_shader_uniform_catalog", exposes_shader_uniform_catalog);