Map renderer sampler state to OpenGL

src/renderer_gl/opengl_capabilities.cpp

@@ -116,6 +116,9 @@ 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_nearest_mipmap_nearest = 0x2700U;
+constexpr std::uint32_t gl_linear_mipmap_nearest = 0x2701U;
+constexpr std::uint32_t gl_nearest_mipmap_linear = 0x2702U;
 constexpr std::uint32_t gl_linear_mipmap_linear = 0x2703U;
 constexpr std::uint32_t gl_nearest = 0x2600U;
 constexpr std::uint32_t gl_texture_mag_filter = 0x2800U;
@@ -940,6 +943,34 @@ OpenGlEnumMapping sampler_filter_for_renderer_filter(pp::renderer::SamplerFilter
     }
 }
 
+OpenGlEnumMapping sampler_min_filter_for_renderer_filters(
+    pp::renderer::SamplerFilter min_filter,
+    pp::renderer::SamplerFilter mip_filter) noexcept
+{
+    switch (min_filter) {
+    case pp::renderer::SamplerFilter::nearest:
+        switch (mip_filter) {
+        case pp::renderer::SamplerFilter::nearest:
+            return OpenGlEnumMapping { .value = gl_nearest_mipmap_nearest, .supported = true };
+        case pp::renderer::SamplerFilter::linear:
+            return OpenGlEnumMapping { .value = gl_nearest_mipmap_linear, .supported = true };
+        default:
+            return OpenGlEnumMapping {};
+        }
+    case pp::renderer::SamplerFilter::linear:
+        switch (mip_filter) {
+        case pp::renderer::SamplerFilter::nearest:
+            return OpenGlEnumMapping { .value = gl_linear_mipmap_nearest, .supported = true };
+        case pp::renderer::SamplerFilter::linear:
+            return OpenGlEnumMapping { .value = gl_linear_mipmap_linear, .supported = true };
+        default:
+            return OpenGlEnumMapping {};
+        }
+    default:
+        return OpenGlEnumMapping {};
+    }
+}
+
 OpenGlEnumMapping sampler_address_mode_for_renderer_mode(pp::renderer::SamplerAddressMode mode) noexcept
 {
     switch (mode) {
@@ -956,6 +987,28 @@ OpenGlEnumMapping sampler_address_mode_for_renderer_mode(pp::renderer::SamplerAd
     }
 }
 
+OpenGlSamplerState sampler_state_for_renderer_sampler_desc(pp::renderer::SamplerDesc desc) noexcept
+{
+    const auto min_filter = sampler_min_filter_for_renderer_filters(desc.min_filter, desc.mip_filter);
+    const auto mag_filter = sampler_filter_for_renderer_filter(desc.mag_filter);
+    const auto address_u = sampler_address_mode_for_renderer_mode(desc.address_u);
+    const auto address_v = sampler_address_mode_for_renderer_mode(desc.address_v);
+    const auto address_w = sampler_address_mode_for_renderer_mode(desc.address_w);
+
+    return OpenGlSamplerState {
+        .min_filter = min_filter.value,
+        .mag_filter = mag_filter.value,
+        .wrap_s = address_u.value,
+        .wrap_t = address_v.value,
+        .wrap_r = address_w.value,
+        .supported = min_filter.supported
+            && mag_filter.supported
+            && address_u.supported
+            && address_v.supported
+            && address_w.supported,
+    };
+}
+
 std::uint32_t active_texture_unit(std::uint32_t unit_index) noexcept
 {
     return gl_texture0 + unit_index;