Add GLES2 2D renderer + Linux display manager

First implementation with Linux display manager.

- Add single-threaded mode for EditorResourcePreview (needed for OpenGL).

Co-authored-by: clayjohn <claynjohn@gmail.com>
Co-authored-by: Fabio Alessandrelli <fabio.alessandrelli@gmail.com>

1 files changed, 308 insertions, 0 deletions

diff --git a/drivers/gles2/shaders/effect_blur.glsl b/drivers/gles2/shaders/effect_blur.glsl
new file mode 100644
index 0000000000..7b607dd76a
--- /dev/null
+++ b/drivers/gles2/shaders/effect_blur.glsl
@@ -0,0 +1,308 @@
+/* clang-format off */
+[vertex]
+
+#ifdef USE_GLES_OVER_GL
+#define lowp
+#define mediump
+#define highp
+#else
+precision highp float;
+precision highp int;
+#endif
+
+attribute vec2 vertex_attrib; // attrib:0
+/* clang-format on */
+attribute vec2 uv_in; // attrib:4
+
+varying vec2 uv_interp;
+
+#ifdef USE_BLUR_SECTION
+
+uniform vec4 blur_section;
+
+#endif
+
+void main() {
+	uv_interp = uv_in;
+	gl_Position = vec4(vertex_attrib, 0.0, 1.0);
+#ifdef USE_BLUR_SECTION
+
+	uv_interp = blur_section.xy + uv_interp * blur_section.zw;
+	gl_Position.xy = (blur_section.xy + (gl_Position.xy * 0.5 + 0.5) * blur_section.zw) * 2.0 - 1.0;
+#endif
+}
+
+/* clang-format off */
+[fragment]
+
+// texture2DLodEXT and textureCubeLodEXT are fragment shader specific.
+// Do not copy these defines in the vertex section.
+#ifndef USE_GLES_OVER_GL
+#ifdef GL_EXT_shader_texture_lod
+#extension GL_EXT_shader_texture_lod : enable
+#define texture2DLod(img, coord, lod) texture2DLodEXT(img, coord, lod)
+#define textureCubeLod(img, coord, lod) textureCubeLodEXT(img, coord, lod)
+#endif
+#endif // !USE_GLES_OVER_GL
+
+#ifdef GL_ARB_shader_texture_lod
+#extension GL_ARB_shader_texture_lod : enable
+#endif
+
+#if !defined(GL_EXT_shader_texture_lod) && !defined(GL_ARB_shader_texture_lod)
+#define texture2DLod(img, coord, lod) texture2D(img, coord, lod)
+#define textureCubeLod(img, coord, lod) textureCube(img, coord, lod)
+#endif
+
+#ifdef USE_GLES_OVER_GL
+#define lowp
+#define mediump
+#define highp
+#else
+#if defined(USE_HIGHP_PRECISION)
+precision highp float;
+precision highp int;
+#else
+precision mediump float;
+precision mediump int;
+#endif
+#endif
+
+varying vec2 uv_interp;
+/* clang-format on */
+uniform sampler2D source_color; //texunit:0
+
+uniform float lod;
+uniform vec2 pixel_size;
+
+#if defined(GLOW_GAUSSIAN_HORIZONTAL) || defined(GLOW_GAUSSIAN_VERTICAL)
+
+uniform float glow_strength;
+
+#endif
+
+#if defined(DOF_FAR_BLUR) || defined(DOF_NEAR_BLUR)
+
+#ifdef USE_GLES_OVER_GL
+#ifdef DOF_QUALITY_LOW
+const int dof_kernel_size = 5;
+const int dof_kernel_from = 2;
+const float dof_kernel[5] = float[](0.153388, 0.221461, 0.250301, 0.221461, 0.153388);
+#endif
+
+#ifdef DOF_QUALITY_MEDIUM
+const int dof_kernel_size = 11;
+const int dof_kernel_from = 5;
+const float dof_kernel[11] = float[](0.055037, 0.072806, 0.090506, 0.105726, 0.116061, 0.119726, 0.116061, 0.105726, 0.090506, 0.072806, 0.055037);
+
+#endif
+
+#ifdef DOF_QUALITY_HIGH
+const int dof_kernel_size = 21;
+const int dof_kernel_from = 10;
+const float dof_kernel[21] = float[](0.028174, 0.032676, 0.037311, 0.041944, 0.046421, 0.050582, 0.054261, 0.057307, 0.059587, 0.060998, 0.061476, 0.060998, 0.059587, 0.057307, 0.054261, 0.050582, 0.046421, 0.041944, 0.037311, 0.032676, 0.028174);
+#endif
+#endif
+
+uniform sampler2D dof_source_depth; //texunit:1
+uniform float dof_begin;
+uniform float dof_end;
+uniform vec2 dof_dir;
+uniform float dof_radius;
+
+#endif
+
+#ifdef GLOW_FIRST_PASS
+
+uniform highp float luminance_cap;
+
+uniform float glow_bloom;
+uniform float glow_hdr_threshold;
+uniform float glow_hdr_scale;
+
+#endif
+
+uniform float camera_z_far;
+uniform float camera_z_near;
+
+void main() {
+#ifdef GLOW_GAUSSIAN_HORIZONTAL
+	vec2 pix_size = pixel_size;
+	pix_size *= 0.5; //reading from larger buffer, so use more samples
+	vec4 color = texture2DLod(source_color, uv_interp + vec2(0.0, 0.0) * pix_size, lod) * 0.174938;
+	color += texture2DLod(source_color, uv_interp + vec2(1.0, 0.0) * pix_size, lod) * 0.165569;
+	color += texture2DLod(source_color, uv_interp + vec2(2.0, 0.0) * pix_size, lod) * 0.140367;
+	color += texture2DLod(source_color, uv_interp + vec2(3.0, 0.0) * pix_size, lod) * 0.106595;
+	color += texture2DLod(source_color, uv_interp + vec2(-1.0, 0.0) * pix_size, lod) * 0.165569;
+	color += texture2DLod(source_color, uv_interp + vec2(-2.0, 0.0) * pix_size, lod) * 0.140367;
+	color += texture2DLod(source_color, uv_interp + vec2(-3.0, 0.0) * pix_size, lod) * 0.106595;
+	color *= glow_strength;
+	gl_FragColor = color;
+#endif
+
+#ifdef GLOW_GAUSSIAN_VERTICAL
+	vec4 color = texture2DLod(source_color, uv_interp + vec2(0.0, 0.0) * pixel_size, lod) * 0.288713;
+	color += texture2DLod(source_color, uv_interp + vec2(0.0, 1.0) * pixel_size, lod) * 0.233062;
+	color += texture2DLod(source_color, uv_interp + vec2(0.0, 2.0) * pixel_size, lod) * 0.122581;
+	color += texture2DLod(source_color, uv_interp + vec2(0.0, -1.0) * pixel_size, lod) * 0.233062;
+	color += texture2DLod(source_color, uv_interp + vec2(0.0, -2.0) * pixel_size, lod) * 0.122581;
+	color *= glow_strength;
+	gl_FragColor = color;
+#endif
+
+#ifndef USE_GLES_OVER_GL
+#if defined(DOF_FAR_BLUR) || defined(DOF_NEAR_BLUR)
+
+#ifdef DOF_QUALITY_LOW
+	const int dof_kernel_size = 5;
+	const int dof_kernel_from = 2;
+	float dof_kernel[5];
+	dof_kernel[0] = 0.153388;
+	dof_kernel[1] = 0.221461;
+	dof_kernel[2] = 0.250301;
+	dof_kernel[3] = 0.221461;
+	dof_kernel[4] = 0.153388;
+#endif
+
+#ifdef DOF_QUALITY_MEDIUM
+	const int dof_kernel_size = 11;
+	const int dof_kernel_from = 5;
+	float dof_kernel[11];
+	dof_kernel[0] = 0.055037;
+	dof_kernel[1] = 0.072806;
+	dof_kernel[2] = 0.090506;
+	dof_kernel[3] = 0.105726;
+	dof_kernel[4] = 0.116061;
+	dof_kernel[5] = 0.119726;
+	dof_kernel[6] = 0.116061;
+	dof_kernel[7] = 0.105726;
+	dof_kernel[8] = 0.090506;
+	dof_kernel[9] = 0.072806;
+	dof_kernel[10] = 0.055037;
+#endif
+
+#ifdef DOF_QUALITY_HIGH
+	const int dof_kernel_size = 21;
+	const int dof_kernel_from = 10;
+	float dof_kernel[21];
+	dof_kernel[0] = 0.028174;
+	dof_kernel[1] = 0.032676;
+	dof_kernel[2] = 0.037311;
+	dof_kernel[3] = 0.041944;
+	dof_kernel[4] = 0.046421;
+	dof_kernel[5] = 0.050582;
+	dof_kernel[6] = 0.054261;
+	dof_kernel[7] = 0.057307;
+	dof_kernel[8] = 0.059587;
+	dof_kernel[9] = 0.060998;
+	dof_kernel[10] = 0.061476;
+	dof_kernel[11] = 0.060998;
+	dof_kernel[12] = 0.059587;
+	dof_kernel[13] = 0.057307;
+	dof_kernel[14] = 0.054261;
+	dof_kernel[15] = 0.050582;
+	dof_kernel[16] = 0.046421;
+	dof_kernel[17] = 0.041944;
+	dof_kernel[18] = 0.037311;
+	dof_kernel[19] = 0.032676;
+	dof_kernel[20] = 0.028174;
+#endif
+#endif
+#endif //!USE_GLES_OVER_GL
+
+#ifdef DOF_FAR_BLUR
+
+	vec4 color_accum = vec4(0.0);
+
+	float depth = texture2DLod(dof_source_depth, uv_interp, 0.0).r;
+	depth = depth * 2.0 - 1.0;
+#ifdef USE_ORTHOGONAL_PROJECTION
+	depth = ((depth + (camera_z_far + camera_z_near) / (camera_z_far - camera_z_near)) * (camera_z_far - camera_z_near)) / 2.0;
+#else
+	depth = 2.0 * camera_z_near * camera_z_far / (camera_z_far + camera_z_near - depth * (camera_z_far - camera_z_near));
+#endif
+
+	float amount = smoothstep(dof_begin, dof_end, depth);
+	float k_accum = 0.0;
+
+	for (int i = 0; i < dof_kernel_size; i++) {
+		int int_ofs = i - dof_kernel_from;
+		vec2 tap_uv = uv_interp + dof_dir * float(int_ofs) * amount * dof_radius;
+
+		float tap_k = dof_kernel[i];
+
+		float tap_depth = texture2D(dof_source_depth, tap_uv, 0.0).r;
+		tap_depth = tap_depth * 2.0 - 1.0;
+#ifdef USE_ORTHOGONAL_PROJECTION
+		tap_depth = ((tap_depth + (camera_z_far + camera_z_near) / (camera_z_far - camera_z_near)) * (camera_z_far - camera_z_near)) / 2.0;
+#else
+		tap_depth = 2.0 * camera_z_near * camera_z_far / (camera_z_far + camera_z_near - tap_depth * (camera_z_far - camera_z_near));
+#endif
+		float tap_amount = int_ofs == 0 ? 1.0 : smoothstep(dof_begin, dof_end, tap_depth);
+		tap_amount *= tap_amount * tap_amount; //prevent undesired glow effect
+
+		vec4 tap_color = texture2DLod(source_color, tap_uv, 0.0) * tap_k;
+
+		k_accum += tap_k * tap_amount;
+		color_accum += tap_color * tap_amount;
+	}
+
+	if (k_accum > 0.0) {
+		color_accum /= k_accum;
+	}
+
+	gl_FragColor = color_accum; ///k_accum;
+
+#endif
+
+#ifdef DOF_NEAR_BLUR
+
+	vec4 color_accum = vec4(0.0);
+
+	float max_accum = 0.0;
+
+	for (int i = 0; i < dof_kernel_size; i++) {
+		int int_ofs = i - dof_kernel_from;
+		vec2 tap_uv = uv_interp + dof_dir * float(int_ofs) * dof_radius;
+		float ofs_influence = max(0.0, 1.0 - abs(float(int_ofs)) / float(dof_kernel_from));
+
+		float tap_k = dof_kernel[i];
+
+		vec4 tap_color = texture2DLod(source_color, tap_uv, 0.0);
+
+		float tap_depth = texture2D(dof_source_depth, tap_uv, 0.0).r;
+		tap_depth = tap_depth * 2.0 - 1.0;
+#ifdef USE_ORTHOGONAL_PROJECTION
+		tap_depth = ((tap_depth + (camera_z_far + camera_z_near) / (camera_z_far - camera_z_near)) * (camera_z_far - camera_z_near)) / 2.0;
+#else
+		tap_depth = 2.0 * camera_z_near * camera_z_far / (camera_z_far + camera_z_near - tap_depth * (camera_z_far - camera_z_near));
+#endif
+		float tap_amount = 1.0 - smoothstep(dof_end, dof_begin, tap_depth);
+		tap_amount *= tap_amount * tap_amount; //prevent undesired glow effect
+
+#ifdef DOF_NEAR_FIRST_TAP
+
+		tap_color.a = 1.0 - smoothstep(dof_end, dof_begin, tap_depth);
+
+#endif
+
+		max_accum = max(max_accum, tap_amount * ofs_influence);
+
+		color_accum += tap_color * tap_k;
+	}
+
+	color_accum.a = max(color_accum.a, sqrt(max_accum));
+
+	gl_FragColor = color_accum;
+
+#endif
+
+#ifdef GLOW_FIRST_PASS
+
+	float luminance = max(gl_FragColor.r, max(gl_FragColor.g, gl_FragColor.b));
+	float feedback = max(smoothstep(glow_hdr_threshold, glow_hdr_threshold + glow_hdr_scale, luminance), glow_bloom);
+
+	gl_FragColor = min(gl_FragColor * feedback, vec4(luminance_cap));
+
+#endif
+}