drawing: use a templated class to read vertex data

Support reading vertex arrays whose values are encoded in types other than float. For the time being, we always use floats internally for the vertex coordinate, normals and texture coordinates passed to GX. Remove a couple of optimized drawing functions, since the optimization does not seem worth the complexity.
devkitPro · Jun 26, 2024 · 651bdfa · 651bdfa
1 parent f5d4eb5
commit 651bdfa
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Showing 5 changed files with 257 additions and 139 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -19,6 +19,8 @@ set(TARGET opengx)
 include(GNUInstallDirs)
 
 add_library(${TARGET} STATIC
+    src/arrays.cpp
+    src/arrays.h
     src/call_lists.c
     src/call_lists.h
     src/debug.c

diff --git a/src/arrays.cpp b/src/arrays.cpp
@@ -0,0 +1,120 @@
+/*****************************************************************************
+Copyright (c) 2011  David Guillen Fandos ([email protected])
+Copyright (c) 2024  Alberto Mardegan ([email protected])
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+3. Neither the name of copyright holders nor the names of its
+   contributors may be used to endorse or promote products derived
+   from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL COPYRIGHT HOLDERS OR CONTRIBUTORS
+BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+*****************************************************************************/
+
+#include "arrays.h"
+
+#include "debug.h"
+
+#include <variant>
+
+struct GenericDataReaderBase {
+    GenericDataReaderBase(int stride, int element_size):
+        given_stride(stride), element_size(element_size) {}
+
+    virtual void read_float(int index, float *elements) = 0;
+
+    void set_num_elements(int n) {
+        num_elements = n;
+    }
+
+    char element_size;
+    char num_elements = 1;
+    uint16_t given_stride = 0;
+};
+
+template <typename T>
+struct GenericDataReader: public GenericDataReaderBase {
+    GenericDataReader(const void *data, int stride):
+        GenericDataReaderBase(stride, sizeof(T)),
+        data(static_cast<const char *>(data))
+        {}
+
+    int compute_stride() const {
+        return given_stride != 0 ? given_stride : (sizeof(T) * num_elements);
+    }
+
+    template <typename R>
+    void read(int index, R *elements) {
+        int stride = compute_stride();
+        const T *ptr = reinterpret_cast<const T*>(data + stride * index);
+        for (int i = 0; i < num_elements; i++) {
+            elements[i] = *ptr;
+            ptr++;
+        }
+    }
+
+    void read_float(int index, float *elements) override {
+        read(index, elements);
+    }
+
+    const char *data;
+};
+
+using ReaderVariant = std::variant<OgxArrayReader,
+                                   GenericDataReaderBase,
+                                   GenericDataReader<float>,
+                                   GenericDataReader<double>,
+                                   GenericDataReader<int16_t>,
+                                   GenericDataReader<int32_t>>;
+
+void _ogx_array_reader_init(OgxArrayReader *reader,
+                                  const void *data,
+                                  GLenum type, int stride)
+{
+    switch (type) {
+    case GL_SHORT:
+        new (reader) GenericDataReader<int16_t>(data, stride);
+        break;
+    case GL_INT:
+        new (reader) GenericDataReader<int32_t>(data, stride);
+        break;
+    case GL_FLOAT:
+        new (reader) GenericDataReader<float>(data, stride);
+        break;
+    case GL_DOUBLE:
+        new (reader) GenericDataReader<double>(data, stride);
+        break;
+    default:
+        warning("Unknown array data type %x\n", type);
+    }
+}
+
+void _ogx_array_reader_set_num_elements(OgxArrayReader *reader, int n)
+{
+    GenericDataReaderBase *r = reinterpret_cast<GenericDataReaderBase *>(reader);
+    r->set_num_elements(n);
+}
+
+void _ogx_array_reader_read_float(OgxArrayReader *reader,
+                                  int index, float *elements)
+{
+    GenericDataReaderBase *r = reinterpret_cast<GenericDataReaderBase *>(reader);
+    r->read_float(index, elements);
+}
diff --git a/src/arrays.h b/src/arrays.h
@@ -0,0 +1,57 @@
+/*****************************************************************************
+Copyright (c) 2011  David Guillen Fandos ([email protected])
+Copyright (c) 2024  Alberto Mardegan ([email protected])
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+3. Neither the name of copyright holders nor the names of its
+   contributors may be used to endorse or promote products derived
+   from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL COPYRIGHT HOLDERS OR CONTRIBUTORS
+BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+*****************************************************************************/
+
+#ifndef OPENGX_ARRAYS_H
+#define OPENGX_ARRAYS_H
+
+#include <GL/gl.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    /* Opaque struct */
+    uint32_t reader[6];
+} OgxArrayReader;
+
+void _ogx_array_reader_init(OgxArrayReader *reader,
+                            const void *data,
+                            GLenum type, int stride);
+void _ogx_array_reader_set_num_elements(OgxArrayReader *reader, int n);
+void _ogx_array_reader_read_float(OgxArrayReader *reader,
+                                  int index, float *elements);
+
+#ifdef __cplusplus
+} // extern C
+#endif
+
+#endif /* OPENGX_ARRAYS_H */