renderer: Frustum culling demo.

Author: heinezen

assets/test/shaders/demo_6_2d.frag.glsl

@@ -0,0 +1,37 @@
+#version 330
+
+in vec2 vert_uv;
+
+layout(location=0) out vec4 col;
+
+uniform sampler2D tex;
+
+// position (top left corner) and size: (x, y, width, height)
+uniform vec4 tile_params;
+
+vec2 uv = vec2(
+	vert_uv.x * tile_params.z + tile_params.x,
+	vert_uv.y * tile_params.w + tile_params.y
+);
+
+void main() {
+	vec4 tex_val = texture(tex, uv);
+	int alpha = int(round(tex_val.a * 255));
+	switch (alpha) {
+		case 0:
+			col = tex_val;
+			discard;
+		case 254:
+			col = vec4(1.0f, 0.0f, 0.0f, 1.0f);
+			break;
+		case 252:
+			col = vec4(0.0f, 1.0f, 0.0f, 1.0f);
+			break;
+		case 250:
+			col = vec4(0.0f, 0.0f, 1.0f, 1.0f);
+			break;
+		default:
+			col = tex_val;
+			break;
+	}
+}

assets/test/shaders/demo_6_2d.vert.glsl

@@ -0,0 +1,83 @@
+#version 330
+
+layout(location=0) in vec2 v_position;
+layout(location=1) in vec2 uv;
+
+out vec2 vert_uv;
+
+// camera parameters for transforming the object position
+// and scaling the subtex to the correct size
+layout (std140) uniform camera {
+    // view matrix (world to view space)
+    mat4  view;
+    // projection matrix (view to clip space)
+    mat4  proj;
+    // inverse zoom factor (1.0 / zoom)
+    // high zoom = upscale subtex
+    // low zoom = downscale subtex
+    float inv_zoom;
+    // inverse viewport size (1.0 / viewport size)
+    vec2  inv_viewport_size;
+};
+
+// position of the object in world space
+uniform vec3 obj_world_position;
+
+// parameters for scaling and moving the subtex
+// to the correct position in clip space
+
+// animation scalefactor
+// scales the vertex positions so that they
+// match the subtex dimensions
+//
+// high animation scale = downscale subtex
+// low animation scale = upscale subtex
+uniform float scale;
+
+// size of the subtex (in pixels)
+uniform vec2 subtex_size;
+
+// offset of the subtex anchor point
+// from the subtex center (in pixels)
+// used to move the subtex so that the anchor point
+// is at the object position
+uniform vec2 anchor_offset;
+
+void main() {
+    // translate the position of the object from world space to clip space
+    // this is the position where we want to draw the subtex in 2D
+	vec4 obj_clip_pos = proj * view * vec4(obj_world_position, 1.0);
+
+    // subtex has to be scaled to account for the zoom factor
+    // and the animation scale factor. essentially this is (animation scale / zoom).
+    float zoom_scale = scale * inv_zoom;
+
+    // Scale the subtex vertices
+    // we have to account for the viewport size to get the correct dimensions
+    // and then scale the subtex to the zoom factor to get the correct size
+    vec2 vert_scale = zoom_scale * subtex_size * inv_viewport_size;
+
+    // Scale the anchor offset with the same method as above
+    // to get the correct anchor position in the viewport
+    vec2 anchor_scale = zoom_scale * anchor_offset * inv_viewport_size;
+
+    // offset the clip position by the offset of the subtex anchor
+    // imagine this as pinning the subtex to the object position at the subtex anchor point
+    obj_clip_pos += vec4(anchor_scale.x, anchor_scale.y, 0.0, 0.0);
+
+    // create a move matrix for positioning the vertices
+    // uses the vert scale and the transformed object position in clip space
+    mat4 move = mat4(vert_scale.x,   0.0,            0.0,            0.0,
+                     0.0,            vert_scale.y,   0.0,            0.0,
+                     0.0,            0.0,            1.0,            0.0,
+                     obj_clip_pos.x, obj_clip_pos.y, obj_clip_pos.z, 1.0);
+
+    // calculate the final vertex position
+    gl_Position = move * vec4(v_position, 0.0, 1.0);
+
+    // flip y axis because OpenGL uses bottom-left as its origin
+    float uv_x = uv.x;
+    float uv_y = 1.0 - uv.y;
+
+    vert_uv = vec2(uv_x, uv_y);
+}

assets/test/shaders/demo_6_2d_frame.frag.glsl

@@ -0,0 +1,7 @@
+#version 330
+
+out vec4 col;
+
+void main() {
+    col = vec4(1.0, 0.0, 0.0, 0.8);
+}

assets/test/shaders/demo_6_2d_frame.vert.glsl

@@ -0,0 +1,58 @@
+#version 330
+
+layout(location=0) in vec2 v_position;
+
+// camera parameters for transforming the object position
+// and scaling the subtex to the correct size
+layout (std140) uniform camera {
+    // view matrix (world to view space)
+    mat4  view;
+    // projection matrix (view to clip space)
+    mat4  proj;
+    // inverse zoom factor (1.0 / zoom)
+    float inv_zoom;
+    // inverse viewport size (1.0 / viewport size)
+    vec2  inv_viewport_size;
+};
+
+// position of the object in world space
+uniform vec3 obj_world_position;
+
+// parameters for scaling and moving the subtex
+// to the correct position in clip space
+
+// animation scalefactor
+// scales the vertex positions so that they
+// match the subtex dimensions
+//
+// high animation scale = downscale subtex
+// low animation scale = upscale subtex
+uniform float scale;
+
+// size of the frame (in pixels)
+uniform vec2 frame_size;
+
+void main() {
+    // translate the position of the object from world space to clip space
+    // this is the position where we want to draw the subtex in 2D
+	vec4 obj_clip_pos = proj * view * vec4(obj_world_position, 1.0);
+
+    // subtex has to be scaled to account for the zoom factor
+    // and the animation scale factor. essentially this is (animation scale / zoom).
+    float zoom_scale = scale * inv_zoom;
+
+    // Scale the subtex vertices
+    // we have to account for the viewport size to get the correct dimensions
+    // and then scale the frame to the zoom factor to get the correct size
+    vec2 vert_scale = zoom_scale * frame_size * inv_viewport_size;
+
+    // create a move matrix for positioning the vertices
+    // uses the vert scale and the transformed object position in clip space
+    mat4 move = mat4(vert_scale.x,   0.0,            0.0,            0.0,
+                     0.0,            vert_scale.y,   0.0,            0.0,
+                     0.0,            0.0,            1.0,            0.0,
+                     obj_clip_pos.x, obj_clip_pos.y, obj_clip_pos.z, 1.0);
+
+    // calculate the final vertex position
+    gl_Position = move * vec4(v_position, 0.0, 1.0);
+}

assets/test/shaders/demo_6_3d.frag.glsl

@@ -0,0 +1,13 @@
+#version 330
+
+in vec2 tex_pos;
+
+layout(location=0) out vec4 out_col;
+
+uniform sampler2D tex;
+
+void main()
+{
+    vec4 tex_val = texture(tex, tex_pos);
+	out_col = tex_val;
+}

assets/test/shaders/demo_6_3d.vert.glsl

@@ -0,0 +1,24 @@
+#version 330
+
+layout (location = 0) in vec3 position;
+layout (location = 1) in vec2 uv;
+
+out vec2 tex_pos;
+
+// camera parameters for transforming the object position
+// and scaling the subtex to the correct size
+layout (std140) uniform camera {
+    // view matrix (world to view space)
+    mat4  view;
+    // projection matrix (view to clip space)
+    mat4  proj;
+    // inverse zoom factor (1.0 / zoom)
+    float inv_zoom;
+    // inverse viewport size (1.0 / viewport size)
+    vec2  inv_viewport_size;
+};
+
+void main() {
+	gl_Position = proj * view * vec4(position, 1.0);
+    tex_pos = vec2(uv.x, 1.0 - uv.y);
+}

assets/test/shaders/demo_6_display.frag.glsl

@@ -0,0 +1,10 @@
+#version 330
+
+uniform sampler2D color_texture;
+
+in vec2 v_uv;
+out vec4 col;
+
+void main() {
+	col = texture(color_texture, v_uv);
+}

assets/test/shaders/demo_6_display.vert.glsl

@@ -0,0 +1,10 @@
+#version 330
+
+layout(location=0) in vec2 position;
+layout(location=1) in vec2 uv;
+out vec2 v_uv;
+
+void main() {
+	gl_Position = vec4(position, 0.0, 1.0);
+	v_uv = uv;
+}

libopenage/renderer/demo/CMakeLists.txt

@@ -5,6 +5,7 @@ add_sources(libopenage
     demo_3.cpp
     demo_4.cpp
     demo_5.cpp
+    demo_6.cpp
     stresstest_0.cpp
     stresstest_1.cpp
 	tests.cpp

libopenage/renderer/demo/demo_0.cpp

@@ -1,4 +1,4 @@
-// Copyright 2015-2024 the openage authors. See copying.md for legal info.
+// Copyright 2023-2024 the openage authors. See copying.md for legal info.
 
 #include "demo_0.h"