Merge pull request #33 from Wunkolo/span-vertex

Use `std::span` to pass vertex data

.clang-format

@@ -1,6 +1,6 @@
 BasedOnStyle: Google
 IndentWidth: 4
-ColumnLimit: 120
+ColumnLimit: 150
 AccessModifierOffset: -2
 TabWidth: 4
 NamespaceIndentation: All

include/opengl.hpp

@@ -30,6 +30,19 @@
 
 #include "gl3w.h"
 
+// Check if we have C++20. If yes, we can add C++20 std::span support
+#ifdef _MSVC_LANG // MSVC does not properly define __cplusplus without a compiler flag...
+#if _MSVC_LANG >= 202002L
+#define OPENGL_HAVE_CPP20
+#endif
+#elif __cplusplus >= 202002L
+#define OPENGL_HAVE_CPP20
+#endif // MSVC_LANG
+
+#ifdef OPENGL_HAVE_CPP20
+#include <span>
+#endif
+
 // Uncomment the following define if you want GL objects to automatically free themselves when their lifetime ends
 // #define OPENGL_DESTRUCTORS
 
@@ -399,6 +412,19 @@ namespace OpenGL {
 		void bufferVertsSub(VertType* vertices, int vertCount, GLintptr offset = 0) {
 			glBufferSubData(GL_ARRAY_BUFFER, offset, sizeof(VertType) * vertCount, vertices);
 		}
+
+        // If C++20 is available, add overloads that take std::span instead of raw pointers
+#ifdef OPENGL_HAVE_CPP20
+		template <typename VertType>
+		void bufferVerts(std::span<const VertType> vertices, GLenum usage = GL_DYNAMIC_DRAW) {
+			glBufferData(GL_ARRAY_BUFFER, sizeof(VertType) * vertices.size(), vertices.data(), usage);
+		}
+
+		template <typename VertType>
+		void bufferVertsSub(std::span<const VertType> vertices, GLintptr offset = 0) {
+			glBufferSubData(GL_ARRAY_BUFFER, offset, sizeof(VertType) * vertices.size(), vertices.data());
+		}
+#endif
 	};
 
     enum DepthFunc {

include/renderer_gl/renderer_gl.hpp

@@ -1,5 +1,7 @@
 #pragma once
 #include <array>
+#include <span>
+
 #include "helpers.hpp"
 #include "logger.hpp"
 #include "opengl.hpp"
@@ -73,7 +75,7 @@ public:
 	void getGraphicsContext();                                                                      // Set up graphics context for rendering
 	void clearBuffer(u32 startAddress, u32 endAddress, u32 value, u32 control);                     // Clear a GPU buffer in VRAM
 	void displayTransfer(u32 inputAddr, u32 outputAddr, u32 inputSize, u32 outputSize, u32 flags);  // Perform display transfer
-	void drawVertices(OpenGL::Primitives primType, Vertex* vertices, u32 count); // Draw the given vertices
+	void drawVertices(OpenGL::Primitives primType, std::span<const Vertex> vertices);               // Draw the given vertices
 
 	void setFBSize(u32 width, u32 height) {
 		fbSize.x() = width;

src/core/PICA/gpu.cpp

@@ -1,7 +1,10 @@
 #include "PICA/gpu.hpp"
+
+#include <array>
+#include <cstdio>
+
 #include "PICA/float_types.hpp"
 #include "PICA/regs.hpp"
-#include <cstdio>
 
 using namespace Floats;
 
@@ -41,7 +44,7 @@ void GPU::drawArrays(bool indexed) {
 		drawArrays<false>();
 }
 
-Vertex* vertices = new Vertex[Renderer::vertexBufferSize];
+static std::array<Vertex, Renderer::vertexBufferSize> vertices;
 
 template <bool indexed>
 void GPU::drawArrays() {
@@ -205,7 +208,7 @@ void GPU::drawArrays() {
 		OpenGL::Triangle, OpenGL::TriangleStrip, OpenGL::TriangleFan, OpenGL::Triangle
 	};
 	const auto shape = primTypes[primType];
-	renderer.drawVertices(shape, vertices, vertexCount);
+	renderer.drawVertices(shape, std::span(vertices).first(vertexCount));
 }
 
 Vertex GPU::getImmediateModeVertex() {

src/core/PICA/regs.cpp

@@ -157,7 +157,7 @@ void GPU::writeInternalReg(u32 index, u32 value, u32 mask) {
 						// If we've reached 3 verts, issue a draw call
 						// Handle rendering depending on the primitive type
 						if (immediateModeVertIndex == 3) {
-							renderer.drawVertices(OpenGL::Triangle, &immediateModeVertices[0], 3);
+							renderer.drawVertices(OpenGL::Triangle, immediateModeVertices);
 
 							switch (primType) {
 								// Triangle or geometry primitive. Draw a triangle and discard all vertices

src/core/renderer_gl/renderer_gl.cpp

@@ -213,7 +213,6 @@ void Renderer::initGraphicsContext() {
 
 void Renderer::getGraphicsContext() {
 	OpenGL::disableScissor();
-	OpenGL::setViewport(400, 240);
 
 	vbo.bind();
 	vao.bind();
@@ -265,7 +264,7 @@ void Renderer::setupBlending() {
 	}
 }
 
-void Renderer::drawVertices(OpenGL::Primitives primType, Vertex* vertices, u32 count) {
+void Renderer::drawVertices(OpenGL::Primitives primType, std::span<const Vertex> vertices) {
 	// Adjust alpha test if necessary
 	const u32 alphaControl = regs[PICAInternalRegs::AlphaTestConfig];
 	if (alphaControl != oldAlphaControl) {
@@ -352,8 +351,8 @@ void Renderer::drawVertices(OpenGL::Primitives primType, Vertex* vertices, u32 c
 		}
 	}
 
-	vbo.bufferVertsSub(vertices, count);
+	vbo.bufferVertsSub(vertices);
-	OpenGL::draw(primType, count);
+	OpenGL::draw(primType, vertices.size());
 }
 
 constexpr u32 topScreenBuffer = 0x1f000000;