Rename GLES2 driver to OpenGL to prepare for the upgrade to GLES3

- Use lowercase driver names for the `--rendering-driver`
  command line argument.

1 files changed, 343 insertions, 0 deletions

diff --git a/drivers/opengl/shaders/tonemap.glsl b/drivers/opengl/shaders/tonemap.glsl
new file mode 100644
index 0000000000..0117bdb3d3
--- /dev/null
+++ b/drivers/opengl/shaders/tonemap.glsl
@@ -0,0 +1,343 @@
+/* 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;
+
+void main() {
+	gl_Position = vec4(vertex_attrib, 0.0, 1.0);
+
+	uv_interp = uv_in;
+}
+
+/* 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
+
+// Allows the use of bitshift operators for bicubic upscale
+#ifdef GL_EXT_gpu_shader4
+#extension GL_EXT_gpu_shader4 : enable
+#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
+
+#include "stdlib.glsl"
+
+varying vec2 uv_interp;
+/* clang-format on */
+
+uniform highp sampler2D source; //texunit:0
+
+#if defined(USE_GLOW_LEVEL1) || defined(USE_GLOW_LEVEL2) || defined(USE_GLOW_LEVEL3) || defined(USE_GLOW_LEVEL4) || defined(USE_GLOW_LEVEL5) || defined(USE_GLOW_LEVEL6) || defined(USE_GLOW_LEVEL7)
+#define USING_GLOW // only use glow when at least one glow level is selected
+
+#ifdef USE_MULTI_TEXTURE_GLOW
+uniform highp sampler2D source_glow1; //texunit:2
+uniform highp sampler2D source_glow2; //texunit:3
+uniform highp sampler2D source_glow3; //texunit:4
+uniform highp sampler2D source_glow4; //texunit:5
+uniform highp sampler2D source_glow5; //texunit:6
+uniform highp sampler2D source_glow6; //texunit:7
+#ifdef USE_GLOW_LEVEL7
+uniform highp sampler2D source_glow7; //texunit:8
+#endif
+#else
+uniform highp sampler2D source_glow; //texunit:2
+#endif
+uniform highp float glow_intensity;
+#endif
+
+#ifdef USE_BCS
+uniform vec3 bcs;
+#endif
+
+#ifdef USE_FXAA
+uniform vec2 pixel_size;
+#endif
+
+#ifdef USE_COLOR_CORRECTION
+uniform sampler2D color_correction; //texunit:1
+#endif
+
+#ifdef GL_EXT_gpu_shader4
+#ifdef USE_GLOW_FILTER_BICUBIC
+// w0, w1, w2, and w3 are the four cubic B-spline basis functions
+float w0(float a) {
+	return (1.0 / 6.0) * (a * (a * (-a + 3.0) - 3.0) + 1.0);
+}
+
+float w1(float a) {
+	return (1.0 / 6.0) * (a * a * (3.0 * a - 6.0) + 4.0);
+}
+
+float w2(float a) {
+	return (1.0 / 6.0) * (a * (a * (-3.0 * a + 3.0) + 3.0) + 1.0);
+}
+
+float w3(float a) {
+	return (1.0 / 6.0) * (a * a * a);
+}
+
+// g0 and g1 are the two amplitude functions
+float g0(float a) {
+	return w0(a) + w1(a);
+}
+
+float g1(float a) {
+	return w2(a) + w3(a);
+}
+
+// h0 and h1 are the two offset functions
+float h0(float a) {
+	return -1.0 + w1(a) / (w0(a) + w1(a));
+}
+
+float h1(float a) {
+	return 1.0 + w3(a) / (w2(a) + w3(a));
+}
+
+uniform ivec2 glow_texture_size;
+
+vec4 texture2D_bicubic(sampler2D tex, vec2 uv, int p_lod) {
+	float lod = float(p_lod);
+	vec2 tex_size = vec2(glow_texture_size >> p_lod);
+	vec2 texel_size = vec2(1.0) / tex_size;
+
+	uv = uv * tex_size + vec2(0.5);
+
+	vec2 iuv = floor(uv);
+	vec2 fuv = fract(uv);
+
+	float g0x = g0(fuv.x);
+	float g1x = g1(fuv.x);
+	float h0x = h0(fuv.x);
+	float h1x = h1(fuv.x);
+	float h0y = h0(fuv.y);
+	float h1y = h1(fuv.y);
+
+	vec2 p0 = (vec2(iuv.x + h0x, iuv.y + h0y) - vec2(0.5)) * texel_size;
+	vec2 p1 = (vec2(iuv.x + h1x, iuv.y + h0y) - vec2(0.5)) * texel_size;
+	vec2 p2 = (vec2(iuv.x + h0x, iuv.y + h1y) - vec2(0.5)) * texel_size;
+	vec2 p3 = (vec2(iuv.x + h1x, iuv.y + h1y) - vec2(0.5)) * texel_size;
+
+	return (g0(fuv.y) * (g0x * texture2DLod(tex, p0, lod) + g1x * texture2DLod(tex, p1, lod))) +
+		   (g1(fuv.y) * (g0x * texture2DLod(tex, p2, lod) + g1x * texture2DLod(tex, p3, lod)));
+}
+
+#define GLOW_TEXTURE_SAMPLE(m_tex, m_uv, m_lod) texture2D_bicubic(m_tex, m_uv, m_lod)
+#else //!USE_GLOW_FILTER_BICUBIC
+#define GLOW_TEXTURE_SAMPLE(m_tex, m_uv, m_lod) texture2DLod(m_tex, m_uv, float(m_lod))
+#endif //USE_GLOW_FILTER_BICUBIC
+
+#else //!GL_EXT_gpu_shader4
+#define GLOW_TEXTURE_SAMPLE(m_tex, m_uv, m_lod) texture2DLod(m_tex, m_uv, float(m_lod))
+#endif //GL_EXT_gpu_shader4
+
+vec3 apply_glow(vec3 color, vec3 glow) { // apply glow using the selected blending mode
+#ifdef USE_GLOW_REPLACE
+	color = glow;
+#endif
+
+#ifdef USE_GLOW_SCREEN
+	color = max((color + glow) - (color * glow), vec3(0.0));
+#endif
+
+#ifdef USE_GLOW_SOFTLIGHT
+	glow = glow * vec3(0.5) + vec3(0.5);
+
+	color.r = (glow.r <= 0.5) ? (color.r - (1.0 - 2.0 * glow.r) * color.r * (1.0 - color.r)) : (((glow.r > 0.5) && (color.r <= 0.25)) ? (color.r + (2.0 * glow.r - 1.0) * (4.0 * color.r * (4.0 * color.r + 1.0) * (color.r - 1.0) + 7.0 * color.r)) : (color.r + (2.0 * glow.r - 1.0) * (sqrt(color.r) - color.r)));
+	color.g = (glow.g <= 0.5) ? (color.g - (1.0 - 2.0 * glow.g) * color.g * (1.0 - color.g)) : (((glow.g > 0.5) && (color.g <= 0.25)) ? (color.g + (2.0 * glow.g - 1.0) * (4.0 * color.g * (4.0 * color.g + 1.0) * (color.g - 1.0) + 7.0 * color.g)) : (color.g + (2.0 * glow.g - 1.0) * (sqrt(color.g) - color.g)));
+	color.b = (glow.b <= 0.5) ? (color.b - (1.0 - 2.0 * glow.b) * color.b * (1.0 - color.b)) : (((glow.b > 0.5) && (color.b <= 0.25)) ? (color.b + (2.0 * glow.b - 1.0) * (4.0 * color.b * (4.0 * color.b + 1.0) * (color.b - 1.0) + 7.0 * color.b)) : (color.b + (2.0 * glow.b - 1.0) * (sqrt(color.b) - color.b)));
+#endif
+
+#if !defined(USE_GLOW_SCREEN) && !defined(USE_GLOW_SOFTLIGHT) && !defined(USE_GLOW_REPLACE) // no other selected -> additive
+	color += glow;
+#endif
+
+	return color;
+}
+
+vec3 apply_bcs(vec3 color, vec3 bcs) {
+	color = mix(vec3(0.0), color, bcs.x);
+	color = mix(vec3(0.5), color, bcs.y);
+	color = mix(vec3(dot(vec3(1.0), color) * 0.33333), color, bcs.z);
+
+	return color;
+}
+
+vec3 apply_color_correction(vec3 color, sampler2D correction_tex) {
+	color.r = texture2D(correction_tex, vec2(color.r, 0.0)).r;
+	color.g = texture2D(correction_tex, vec2(color.g, 0.0)).g;
+	color.b = texture2D(correction_tex, vec2(color.b, 0.0)).b;
+
+	return color;
+}
+
+vec3 apply_fxaa(vec3 color, vec2 uv_interp, vec2 pixel_size) {
+	const float FXAA_REDUCE_MIN = (1.0 / 128.0);
+	const float FXAA_REDUCE_MUL = (1.0 / 8.0);
+	const float FXAA_SPAN_MAX = 8.0;
+
+	vec3 rgbNW = texture2DLod(source, uv_interp + vec2(-1.0, -1.0) * pixel_size, 0.0).xyz;
+	vec3 rgbNE = texture2DLod(source, uv_interp + vec2(1.0, -1.0) * pixel_size, 0.0).xyz;
+	vec3 rgbSW = texture2DLod(source, uv_interp + vec2(-1.0, 1.0) * pixel_size, 0.0).xyz;
+	vec3 rgbSE = texture2DLod(source, uv_interp + vec2(1.0, 1.0) * pixel_size, 0.0).xyz;
+	vec3 rgbM = color;
+	vec3 luma = vec3(0.299, 0.587, 0.114);
+	float lumaNW = dot(rgbNW, luma);
+	float lumaNE = dot(rgbNE, luma);
+	float lumaSW = dot(rgbSW, luma);
+	float lumaSE = dot(rgbSE, luma);
+	float lumaM = dot(rgbM, luma);
+	float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
+	float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));
+
+	vec2 dir;
+	dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
+	dir.y = ((lumaNW + lumaSW) - (lumaNE + lumaSE));
+
+	float dirReduce = max((lumaNW + lumaNE + lumaSW + lumaSE) *
+								  (0.25 * FXAA_REDUCE_MUL),
+			FXAA_REDUCE_MIN);
+
+	float rcpDirMin = 1.0 / (min(abs(dir.x), abs(dir.y)) + dirReduce);
+	dir = min(vec2(FXAA_SPAN_MAX, FXAA_SPAN_MAX),
+				  max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX),
+						  dir * rcpDirMin)) *
+		  pixel_size;
+
+	vec3 rgbA = 0.5 * (texture2DLod(source, uv_interp + dir * (1.0 / 3.0 - 0.5), 0.0).xyz + texture2DLod(source, uv_interp + dir * (2.0 / 3.0 - 0.5), 0.0).xyz);
+	vec3 rgbB = rgbA * 0.5 + 0.25 * (texture2DLod(source, uv_interp + dir * -0.5, 0.0).xyz +
+											texture2DLod(source, uv_interp + dir * 0.5, 0.0).xyz);
+
+	float lumaB = dot(rgbB, luma);
+	if ((lumaB < lumaMin) || (lumaB > lumaMax)) {
+		return rgbA;
+	} else {
+		return rgbB;
+	}
+}
+
+void main() {
+	vec3 color = texture2DLod(source, uv_interp, 0.0).rgb;
+
+#ifdef USE_FXAA
+	color = apply_fxaa(color, uv_interp, pixel_size);
+#endif
+
+	// Glow
+
+#ifdef USING_GLOW
+	vec3 glow = vec3(0.0);
+#ifdef USE_MULTI_TEXTURE_GLOW
+#ifdef USE_GLOW_LEVEL1
+	glow += GLOW_TEXTURE_SAMPLE(source_glow1, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL2
+	glow += GLOW_TEXTURE_SAMPLE(source_glow2, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL3
+	glow += GLOW_TEXTURE_SAMPLE(source_glow3, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL4
+	glow += GLOW_TEXTURE_SAMPLE(source_glow4, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL5
+	glow += GLOW_TEXTURE_SAMPLE(source_glow5, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL6
+	glow += GLOW_TEXTURE_SAMPLE(source_glow6, uv_interp, 0).rgb;
+#ifdef USE_GLOW_LEVEL7
+	glow += GLOW_TEXTURE_SAMPLE(source_glow7, uv_interp, 0).rgb;
+#endif
+#endif
+#endif
+#endif
+#endif
+#endif
+#endif
+
+#else
+
+#ifdef USE_GLOW_LEVEL1
+	glow += GLOW_TEXTURE_SAMPLE(source_glow, uv_interp, 1).rgb;
+#endif
+
+#ifdef USE_GLOW_LEVEL2
+	glow += GLOW_TEXTURE_SAMPLE(source_glow, uv_interp, 2).rgb;
+#endif
+
+#ifdef USE_GLOW_LEVEL3
+	glow += GLOW_TEXTURE_SAMPLE(source_glow, uv_interp, 3).rgb;
+#endif
+
+#ifdef USE_GLOW_LEVEL4
+	glow += GLOW_TEXTURE_SAMPLE(source_glow, uv_interp, 4).rgb;
+#endif
+
+#ifdef USE_GLOW_LEVEL5
+	glow += GLOW_TEXTURE_SAMPLE(source_glow, uv_interp, 5).rgb;
+#endif
+
+#ifdef USE_GLOW_LEVEL6
+	glow += GLOW_TEXTURE_SAMPLE(source_glow, uv_interp, 6).rgb;
+#endif
+
+#ifdef USE_GLOW_LEVEL7
+	glow += GLOW_TEXTURE_SAMPLE(source_glow, uv_interp, 7).rgb;
+#endif
+#endif //USE_MULTI_TEXTURE_GLOW
+
+	glow *= glow_intensity;
+	color = apply_glow(color, glow);
+#endif
+
+	// Additional effects
+
+#ifdef USE_BCS
+	color = apply_bcs(color, bcs);
+#endif
+
+#ifdef USE_COLOR_CORRECTION
+	color = apply_color_correction(color, color_correction);
+#endif
+
+	gl_FragColor = vec4(color, 1.0);
+}