Adding the ability to make imgui image ids from textures / materials

src/examples/imgui.zig

@@ -1,9 +1,17 @@
 const delve = @import("delve");
 const app = delve.app;
+const graphics = delve.platform.graphics;
 const std = @import("std");
 
 const imgui = delve.imgui;
 
+const test_image_asset = @embedFile("static/test.png");
+var test_texture: graphics.Texture = undefined;
+var test_material: graphics.Material = undefined;
+
+var imgui_texture_1: ?*anyopaque = undefined;
+var imgui_texture_2: ?*anyopaque = undefined;
+
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 
 // This example shows how to use Dear Imgui!
@@ -13,6 +21,7 @@ const imgui_module = delve.modules.Module{
     .init_fn = on_init,
     .tick_fn = on_tick,
     .draw_fn = on_draw,
+    .cleanup_fn = on_cleanup,
 };
 
 var bg_color: [4]f32 = [4]f32{ 0.25, 0.85, 0.55, 1.0 };
@@ -40,6 +49,35 @@ pub fn registerModule() !void {
 
 pub fn on_init() !void {
     delve.debug.log("Imgui Example Initializing.", .{});
+
+    // load an image
+    var test_image = try delve.images.loadBytes(test_image_asset);
+    defer test_image.deinit();
+
+    // make a texture from it
+    test_texture = graphics.Texture.init(test_image);
+
+    // make an imgui texture for it
+    imgui_texture_1 = test_texture.makeImguiTexture();
+
+    // make a material to use a different sampler mode
+    test_material = try graphics.Material.init(.{
+        .shader = graphics.getDefaultShader(),
+        .texture_0 = test_texture,
+        .samplers = &[_]graphics.FilterMode{.NEAREST},
+    });
+
+    // make an imgui image out of our material
+    // materials have more than one texture / sampler, have to pick which to use
+    const img_idx: usize = 0;
+    const sampler_idx: usize = 0;
+    imgui_texture_2 = test_material.makeImguiTexture(img_idx, sampler_idx);
+}
+
+fn on_cleanup() !void {
+    delve.debug.log("Imgui example cleaning up", .{});
+    test_texture.destroy();
+    test_material.deinit();
 }
 
 pub fn on_tick(delta: f32) void {
@@ -52,12 +90,39 @@ pub fn on_tick(delta: f32) void {
     delve.platform.app.startImguiFrame();
 
     imgui.igSetNextWindowPos(.{ .x = 40, .y = 60 }, imgui.ImGuiCond_Once, .{ .x = 0, .y = 0 });
-    imgui.igSetNextWindowSize(.{ .x = 400, .y = 100 }, imgui.ImGuiCond_Once);
+    imgui.igSetNextWindowSize(.{ .x = 400, .y = 300 }, imgui.ImGuiCond_Once);
+
+    // start a window
     _ = imgui.igBegin("Hello Dear ImGui!", 0, imgui.ImGuiWindowFlags_None);
+
     _ = imgui.igColorEdit3("Background", &bg_color[0], imgui.ImGuiColorEditFlags_None);
+
+    _ = imgui.igSpacing();
+
+    _ = imgui.igImage(
+        imgui_texture_1,
+        .{ .x = 80, .y = 80 }, // size
+        .{ .x = 0, .y = 0 }, // u
+        .{ .x = 1.0, .y = 1.0 }, // v
+        .{ .x = 1.0, .y = 1.0, .z = 1.0, .w = 1.0 }, // tint color
+        .{ .x = 1.0, .y = 1.0, .z = 1.0, .w = 1.0 }, // border color
+    );
+
+    _ = imgui.igSpacing();
+
+    _ = imgui.igImage(
+        imgui_texture_2,
+        .{ .x = 140, .y = 140 }, // size
+        .{ .x = 0, .y = 0 }, // u
+        .{ .x = 1.0, .y = 1.0 }, // v
+        .{ .x = 1.0, .y = 1.0, .z = 1.0, .w = 1.0 }, // tint color
+        .{ .x = 1.0, .y = 1.0, .z = 1.0, .w = 1.0 }, // border color
+    );
+
+    // end the window
     imgui.igEnd();
 
-    delve.platform.graphics.setClearColor(delve.colors.Color.fromArray(bg_color));
+    graphics.setClearColor(delve.colors.Color.fromArray(bg_color));
 }
 
 pub fn on_draw() void {

src/framework/platform/graphics.zig

@@ -10,6 +10,7 @@ const sokol_gfx_backend = @import("backends/sokol/graphics.zig");
 const shaders = @import("../graphics/shaders.zig");
 
 const sokol = @import("sokol");
+const simgui = sokol.imgui;
 const slog = sokol.log;
 const sg = sokol.gfx;
 const sapp = sokol.app;
@@ -517,6 +518,12 @@ pub const Texture = struct {
         sg.destroyImage(self.sokol_image.?);
         self.sokol_image = null;
     }
+
+    /// Returns an Imgui Texture ID that can be used with Imgui
+    pub fn makeImguiTexture(self: *const Texture) ?*anyopaque {
+        const img = simgui.makeImage(.{ .image = self.sokol_image.?, .sampler = state.debug_material.state.sokol_samplers[0].? });
+        return simgui.imtextureid(img);
+    }
 };
 
 pub const RenderPassConfig = struct {
@@ -1040,6 +1047,15 @@ pub const Material = struct {
             self.state.shader.applyUniformBlockByName(.FS, "fs_params", asAnything(data.bytes.items));
         }
     }
+
+    /// Returns an Imgui Texture ID from Texture 0 and Sampler 0 that can be used with Imgui
+    pub fn makeImguiTexture(self: *const Material, texture_idx: usize, sampler_idx: usize) ?*anyopaque {
+        const img = simgui.makeImage(.{
+            .image = self.state.textures[texture_idx].?.sokol_image.?,
+            .sampler = self.state.sokol_samplers[sampler_idx].?,
+        });
+        return simgui.imtextureid(img);
+    }
 };
 
 pub const state = struct {