sgl_context and some fixes

.github/workflows/build.yml

@@ -26,4 +26,4 @@ jobs:
         run: |
             zig build debugtext_print --summary all
             zig build clear --summary all
-            # zig build cube --summary all
+            zig build sgl_context --summary all

build.zig

@@ -198,14 +198,14 @@ pub fn build(b: *Builder) !void {
         // "mrt",
         // "saudio",
         // "sgl",
-        // "sgl-context",
+        "sgl_context",
         // "sgl-points",
         // "debugtext",
         "debugtext_print",
         // "debugtext-userfont",
         // "shapes",
     };
-    b.getInstallStep().name = "sokol-d-examples";
+    b.getInstallStep().name = "sokol library";
     inline for (examples) |example| {
         const ldc = try buildLDC(b, sokol, .{
             .name = example,
@@ -214,7 +214,13 @@ pub fn build(b: *Builder) !void {
                 // handmade math
                 rootPath() ++ fmt.comptimePrint("/src/examples/math.d", .{}),
             },
+            .dflags = &.{
+                "--wi", // warnings only (no error)
+                // "-w", // warnings as error
+                "--wo", // warning of deprecated features
+            },
         });
+        ldc.setName("ldc2");
         ldc.step.dependOn(b.getInstallStep());
         const run = b.step(b.fmt("{s}", .{example}), b.fmt("Build example {s}", .{example}));
         run.dependOn(&ldc.step);
@@ -328,11 +334,6 @@ fn buildLDC(b: *Builder, lib: *Builder.CompileStep, comptime config: ldcConfig)
             try cmds.append("--boundscheck=off");
         },
     }
-    // warnings
-    try cmds.append("-w");
-
-    // warning obsolete features
-    try cmds.append("--wo");
 
     // Print character (column) numbers in diagnostics
     try cmds.append("--vcolumns");

src/examples/clear.d

@@ -46,14 +46,16 @@ void cleanup()
 void main()
 {
     sapp.IconDesc icon = {sokol_default: true};
-    sapp.Desc runner = {window_title: "clear.d"};
-    runner.init_cb = &init;
-    runner.frame_cb = &frame;
-    runner.cleanup_cb = &cleanup;
-    runner.width = 640;
-    runner.height = 480;
+    sapp.Desc runner = {
+        window_title: "clear.d",
+        init_cb: &init,
+        frame_cb: &frame,
+        cleanup_cb: &cleanup,
+        width: 640,
+        height: 480,
+        win32_console_attach: true
+    };
     runner.icon = icon;
-    runner.win32_console_attach = true;
-    runner.logger.func = &log.slog_func;
+    runner.logger.func = &log.func;
     sapp.run(runner);
 }

src/examples/sgl_context.d

@@ -0,0 +1,213 @@
+//------------------------------------------------------------------------------
+//  sgl-context.d
+//
+//  Demonstrates how to render into different render passes with sokol-gl.
+//  using contexts.
+//------------------------------------------------------------------------------
+module examples.sgl_context;
+
+import std.stdio;
+import sg = sokol.gfx;
+import sgapp = sokol.glue;
+import sapp = sokol.app;
+import log = sokol.log;
+import sgl = sokol.gl;
+import std.math : sin, cos;
+
+struct State
+{
+    struct Offscreen
+    {
+        sg.PassAction pass_action;
+        sg.Pass pass;
+        sg.Image img;
+        sgl.Context sgl_ctx;
+    }
+
+    struct Display
+    {
+        sg.PassAction pass_action;
+        sg.Sampler smp;
+        sgl.Pipeline sgl_pip;
+    }
+}
+
+enum offscreen_pixel_format = sg.PixelFormat.RGBA8;
+enum offscreen_sample_count = 1;
+enum offscreen_width = 32;
+enum offscreen_height = 32;
+
+State.Offscreen offscreen;
+State.Display display;
+
+void init()
+{
+    sg.Desc gfxd;
+    gfxd.context = sgapp.context();
+    gfxd.logger.func = &log.func;
+    sg.setup(gfxd);
+
+    // setup sokol-gl with the default context compatible with the default
+    // render pass (which means just keep pixelformats and sample count at defaults)
+    //
+    // reduce the vertex- and command-count though, otherwise we just waste memory
+    sgl.Desc gld;
+    gld.max_vertices = 64;
+    gld.max_commands = 16;
+    gld.logger.func = &log.func;
+    sgl.setup(gld);
+
+    // initialize a pass action struct for the default pass to clear to a light-blue color
+    display.pass_action.colors[0].load_action = sg.LoadAction.CLEAR;
+    display.pass_action.colors[0].clear_value.r = 0.5;
+    display.pass_action.colors[0].clear_value.g = 0.7;
+    display.pass_action.colors[0].clear_value.b = 1;
+    display.pass_action.colors[0].clear_value.a = 1;
+
+    // create a sokol-gl pipeline object for 3D rendering into the default pass
+    sg.PipelineDesc pld;
+    pld.cull_mode = sg.CullMode.BACK;
+    pld.depth.write_enabled = true;
+    pld.depth.compare = sg.CompareFunc.LESS_EQUAL;
+    display.sgl_pip = sgl.contextMakePipeline(sgl.defaultContext, pld);
+
+    // create a sokol-gl context compatible with the offscreen render pass
+    // (specific color pixel format, no depth-stencil-surface, no MSAA)
+    sgl.ContextDesc ctd;
+    ctd.max_vertices = 8;
+    ctd.max_commands = 4;
+    ctd.color_format = offscreen_pixel_format,
+    ctd.depth_format = sg.PixelFormat.NONE,
+    ctd.sample_count = offscreen_sample_count,
+
+    offscreen.sgl_ctx = sgl.makeContext(ctd);
+
+    // create an offscreen render target texture, pass and pass-action
+    sg.ImageDesc imgd;
+    imgd.render_target = true,
+    imgd.width = offscreen_width,
+    imgd.height = offscreen_height,
+    imgd.pixel_format = offscreen_pixel_format,
+    imgd.sample_count = offscreen_sample_count,
+
+    offscreen.img = sg.makeImage(imgd);
+
+    sg.PassDesc pass_desc;
+    pass_desc.color_attachments[0].image = offscreen.img;
+    offscreen.pass = sg.makePass(pass_desc);
+
+    offscreen.pass_action.colors[0].load_action = sg.LoadAction.CLEAR;
+    offscreen.pass_action.colors[0].clear_value.r = 0;
+    offscreen.pass_action.colors[0].clear_value.g = 0;
+    offscreen.pass_action.colors[0].clear_value.b = 0;
+    offscreen.pass_action.colors[0].clear_value.a = 1;
+
+    // sampler for sampling the offscreen render target
+    sg.SamplerDesc smd;
+    smd.wrap_u = sg.Wrap.CLAMP_TO_EDGE,
+    smd.wrap_v = sg.Wrap.CLAMP_TO_EDGE,
+    smd.min_filter = sg.Filter.NEAREST,
+    smd.mag_filter = sg.Filter.NEAREST,
+    display.smp = sg.makeSampler(smd);
+}
+
+void frame()
+{
+    const a = sgl.asRadians(sapp.frameCount());
+
+    // draw a rotating quad into the offscreen render target texture
+    sgl.setContext(offscreen.sgl_ctx);
+    sgl.defaults();
+    sgl.matrixModeModelview();
+    sgl.rotate(a, 0, 0, 1);
+    draw_quad();
+
+    // draw a rotating 3D cube, using the offscreen render target as texture
+    sgl.setContext(sgl.defaultContext());
+    sgl.defaults();
+    sgl.enableTexture();
+    sgl.texture(offscreen.img, display.smp);
+    sgl.loadPipeline(display.sgl_pip);
+    sgl.matrixModeProjection();
+    sgl.perspective(sgl.asRadians(45.0), sapp.widthf() / sapp.heightf(), 0.1, 100.0);
+    const(float)[3] eye = [
+        sin(a) * 6.0,
+        sin(a) * 3.0,
+        cos(a) * 6.0,
+    ];
+    sgl.matrixModeModelview();
+    sgl.lookat(eye[0], eye[1], eye[2], 0, 0, 0, 0, 1, 0);
+    draw_cube();
+
+    // do the actual offscreen and display rendering in sokol-gfx passes
+    sg.beginPass(offscreen.pass, offscreen.pass_action);
+    sgl.contextDraw(offscreen.sgl_ctx);
+    sg.endPass();
+    sg.beginDefaultPass(display.pass_action, sapp.width(), sapp.height());
+    sgl.contextDraw(sgl.defaultContext());
+    sg.endPass();
+    sg.commit();
+}
+
+void cleanup()
+{
+    sgl.shutdown();
+    sg.shutdown();
+}
+
+void main()
+{
+    sapp.IconDesc icon = {sokol_default: true};
+    sapp.Desc runner = {
+        window_title: "sgl_context.d",
+        init_cb: &init,
+        frame_cb: &frame,
+        cleanup_cb: &cleanup,
+        width: 800,
+        height: 600,
+        sample_count: 4,
+    };
+    runner.icon = icon;
+    runner.logger.func = &log.func;
+    sapp.run(runner);
+}
+
+void draw_quad()
+{
+    sgl.beginQuads();
+    sgl.v2fC3b(0.0, -1.0, 255, 0, 0);
+    sgl.v2fC3b(1.0, 0.0, 0, 0, 255);
+    sgl.v2fC3b(0.0, 1.0, 0, 255, 255);
+    sgl.v2fC3b(-1.0, 0.0, 0, 255, 0);
+    sgl.end();
+}
+
+void draw_cube()
+{
+    sgl.beginQuads();
+    sgl.v3fT2f(-1.0, 1.0, -1.0, 0.0, 1.0);
+    sgl.v3fT2f(1.0, 1.0, -1.0, 1.0, 1.0);
+    sgl.v3fT2f(1.0, -1.0, -1.0, 1.0, 0.0);
+    sgl.v3fT2f(-1.0, -1.0, -1.0, 0.0, 0.0);
+    sgl.v3fT2f(-1.0, -1.0, 1.0, 0.0, 1.0);
+    sgl.v3fT2f(1.0, -1.0, 1.0, 1.0, 1.0);
+    sgl.v3fT2f(1.0, 1.0, 1.0, 1.0, 0.0);
+    sgl.v3fT2f(-1.0, 1.0, 1.0, 0.0, 0.0);
+    sgl.v3fT2f(-1.0, -1.0, 1.0, 0.0, 1.0);
+    sgl.v3fT2f(-1.0, 1.0, 1.0, 1.0, 1.0);
+    sgl.v3fT2f(-1.0, 1.0, -1.0, 1.0, 0.0);
+    sgl.v3fT2f(-1.0, -1.0, -1.0, 0.0, 0.0);
+    sgl.v3fT2f(1.0, -1.0, 1.0, 0.0, 1.0);
+    sgl.v3fT2f(1.0, -1.0, -1.0, 1.0, 1.0);
+    sgl.v3fT2f(1.0, 1.0, -1.0, 1.0, 0.0);
+    sgl.v3fT2f(1.0, 1.0, 1.0, 0.0, 0.0);
+    sgl.v3fT2f(1.0, -1.0, -1.0, 0.0, 1.0);
+    sgl.v3fT2f(1.0, -1.0, 1.0, 1.0, 1.0);
+    sgl.v3fT2f(-1.0, -1.0, 1.0, 1.0, 0.0);
+    sgl.v3fT2f(-1.0, -1.0, -1.0, 0.0, 0.0);
+    sgl.v3fT2f(-1.0, 1.0, -1.0, 0.0, 1.0);
+    sgl.v3fT2f(-1.0, 1.0, 1.0, 1.0, 1.0);
+    sgl.v3fT2f(1.0, 1.0, 1.0, 1.0, 0.0);
+    sgl.v3fT2f(1.0, 1.0, -1.0, 0.0, 0.0);
+    sgl.end();
+}

src/sokol/gl.d

@@ -18,7 +18,7 @@ enum LogItem {
     CANNOT_DESTROY_DEFAULT_CONTEXT,
 }
 struct Logger {
-    void function(const (char*), uint, uint, const (char*), uint, const (char*), void*) func;
+    extern(C) void function(const (char*), uint, uint, const (char*), uint, const (char*), void*) func;
     void* user_data;
 }
 struct Pipeline {