gl-renderer: move lut_3x1d curves to union

In the next commit we'll add support for more color curves. So move
lut_3x1d to an union.

Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>

3 files changed, 102 insertions, 56 deletions

diff --git a/libweston/renderer-gl/gl-renderer-internal.h b/libweston/renderer-gl/gl-renderer-internal.h
index 71d5f4db..9d409c7a 100644
--- a/libweston/renderer-gl/gl-renderer-internal.h
+++ b/libweston/renderer-gl/gl-renderer-internal.h
@@ -113,17 +113,28 @@ struct gl_shader_config {
 	GLfloat unicolor[4];
 	GLint input_tex_filter; /* GL_NEAREST or GL_LINEAR */
 	GLuint input_tex[GL_SHADER_INPUT_TEX_MAX];
-	GLuint color_pre_curve_lut_tex;
-	GLfloat color_pre_curve_lut_scale_offset[2];
+
+	union {
+		struct {
+			GLuint tex;
+			GLfloat scale_offset[2];
+		} lut_3x1d;
+	} color_pre_curve;
+
 	union {
 		struct {
-			GLuint  tex;
+			GLuint tex;
 			GLfloat scale_offset[2];
 		} lut3d;
 		GLfloat matrix[9];
 	} color_mapping;
-	GLuint color_post_curve_lut_tex;
-	GLfloat color_post_curve_lut_scale_offset[2];
+
+	union {
+		struct {
+			GLuint tex;
+			GLfloat scale_offset[2];
+		} lut_3x1d;
+	} color_post_curve;
 };
 
 struct gl_renderer {
diff --git a/libweston/renderer-gl/gl-shader-config-color-transformation.c b/libweston/renderer-gl/gl-shader-config-color-transformation.c
index d1714492..49224d3d 100644
--- a/libweston/renderer-gl/gl-shader-config-color-transformation.c
+++ b/libweston/renderer-gl/gl-shader-config-color-transformation.c
@@ -41,9 +41,13 @@
 
 struct gl_renderer_color_curve {
 	enum gl_shader_color_curve type;
-	GLuint tex;
-	float scale;
-	float offset;
+	union {
+		struct {
+			GLuint tex;
+			float scale;
+			float offset;
+		} lut_3x1d;
+	} u;
 };
 
 struct gl_renderer_color_mapping {
@@ -69,8 +73,13 @@ struct gl_renderer_color_transform {
 static void
 gl_renderer_color_curve_fini(struct gl_renderer_color_curve *gl_curve)
 {
-	if (gl_curve->tex)
-		glDeleteTextures(1, &gl_curve->tex);
+	switch (gl_curve->type) {
+	case SHADER_COLOR_CURVE_IDENTITY:
+		break;
+	case SHADER_COLOR_CURVE_LUT_3x1D:
+		glDeleteTextures(1, &gl_curve->u.lut_3x1d.tex);
+		break;
+	};
 }
 
 static void
@@ -173,9 +182,9 @@ gl_color_curve_lut_3x1d(struct gl_renderer *gr,
 	free(lut);
 
 	gl_curve->type = SHADER_COLOR_CURVE_LUT_3x1D;
-	gl_curve->tex = tex;
-	gl_curve->scale = (float)(lut_len - 1) / lut_len;
-	gl_curve->offset = 0.5f / lut_len;
+	gl_curve->u.lut_3x1d.tex = tex;
+	gl_curve->u.lut_3x1d.scale = (float)(lut_len - 1) / lut_len;
+	gl_curve->u.lut_3x1d.offset = 0.5f / lut_len;
 
 	return true;
 }
@@ -228,14 +237,8 @@ gl_renderer_color_transform_from(struct gl_renderer *gr,
 {
 	static const struct gl_renderer_color_transform no_op_gl_xform = {
 		.pre_curve.type = SHADER_COLOR_CURVE_IDENTITY,
-		.pre_curve.tex = 0,
-		.pre_curve.scale = 0.0f,
-		.pre_curve.offset = 0.0f,
 		.mapping.type = SHADER_COLOR_MAPPING_IDENTITY,
 		.post_curve.type = SHADER_COLOR_CURVE_IDENTITY,
-		.post_curve.tex = 0,
-		.post_curve.scale = 0.0f,
-		.post_curve.offset = 0.0f,
 	};
 	struct gl_renderer_color_transform *gl_xform;
 	bool ok = false;
@@ -265,11 +268,11 @@ gl_renderer_color_transform_from(struct gl_renderer *gr,
 					     &xform->pre_curve, xform);
 		break;
 	}
-
 	if (!ok) {
 		gl_renderer_color_transform_destroy(gl_xform);
 		return NULL;
 	}
+
 	switch (xform->mapping.type) {
 	case WESTON_COLOR_MAPPING_TYPE_IDENTITY:
 		gl_xform->mapping = no_op_gl_xform.mapping;
@@ -288,6 +291,7 @@ gl_renderer_color_transform_from(struct gl_renderer *gr,
 		gl_renderer_color_transform_destroy(gl_xform);
 		return NULL;
 	}
+
 	switch (xform->post_curve.type) {
 	case WESTON_COLOR_CURVE_TYPE_IDENTITY:
 		gl_xform->post_curve = no_op_gl_xform.post_curve;
@@ -319,14 +323,26 @@ gl_shader_config_set_color_transform(struct gl_renderer *gr,
 		return false;
 
 	sconf->req.color_pre_curve = gl_xform->pre_curve.type;
-	sconf->color_pre_curve_lut_tex = gl_xform->pre_curve.tex;
-	sconf->color_pre_curve_lut_scale_offset[0] = gl_xform->pre_curve.scale;
-	sconf->color_pre_curve_lut_scale_offset[1] = gl_xform->pre_curve.offset;
+	switch (gl_xform->pre_curve.type) {
+	case SHADER_COLOR_CURVE_IDENTITY:
+		break;
+	case SHADER_COLOR_CURVE_LUT_3x1D:
+		sconf->color_pre_curve.lut_3x1d.tex = gl_xform->pre_curve.u.lut_3x1d.tex;
+		sconf->color_pre_curve.lut_3x1d.scale_offset[0] = gl_xform->pre_curve.u.lut_3x1d.scale;
+		sconf->color_pre_curve.lut_3x1d.scale_offset[1] = gl_xform->pre_curve.u.lut_3x1d.offset;
+		break;
+	}
 
 	sconf->req.color_post_curve = gl_xform->post_curve.type;
-	sconf->color_post_curve_lut_tex = gl_xform->post_curve.tex;
-	sconf->color_post_curve_lut_scale_offset[0] = gl_xform->post_curve.scale;
-	sconf->color_post_curve_lut_scale_offset[1] = gl_xform->post_curve.offset;
+	switch (gl_xform->post_curve.type) {
+	case SHADER_COLOR_CURVE_IDENTITY:
+		break;
+	case SHADER_COLOR_CURVE_LUT_3x1D:
+		sconf->color_post_curve.lut_3x1d.tex = gl_xform->post_curve.u.lut_3x1d.tex;
+		sconf->color_post_curve.lut_3x1d.scale_offset[0] = gl_xform->post_curve.u.lut_3x1d.scale;
+		sconf->color_post_curve.lut_3x1d.scale_offset[1] = gl_xform->post_curve.u.lut_3x1d.offset;
+		break;
+	}
 
 	sconf->req.color_mapping = gl_xform->mapping.type;
 	switch (gl_xform->mapping.type) {
diff --git a/libweston/renderer-gl/gl-shaders.c b/libweston/renderer-gl/gl-shaders.c
index a9f38c63..999814d2 100644
--- a/libweston/renderer-gl/gl-shaders.c
+++ b/libweston/renderer-gl/gl-shaders.c
@@ -52,6 +52,8 @@
 #include "fragment-shader.h"
 
 struct gl_shader {
+	struct wl_list link; /* gl_renderer::shader_list */
+	struct timespec last_used;
 	struct gl_shader_requirements key;
 	GLuint program;
 	GLuint vertex_shader, fragment_shader;
@@ -60,8 +62,12 @@ struct gl_shader {
 	GLint tex_uniforms[3];
 	GLint view_alpha_uniform;
 	GLint color_uniform;
-	GLint color_pre_curve_lut_2d_uniform;
-	GLint color_pre_curve_lut_scale_offset_uniform;
+	union {
+		struct {
+			GLint tex_2d_uniform;
+			GLint scale_offset_uniform;
+		} lut_3x1d;
+	} color_pre_curve;
 	union {
 		struct {
 			GLint tex_uniform;
@@ -69,10 +75,12 @@ struct gl_shader {
 		} lut3d;
 		GLint matrix_uniform;
 	} color_mapping;
-	GLint color_post_curve_lut_2d_uniform;
-	GLint color_post_curve_lut_scale_offset_uniform;
-	struct wl_list link; /* gl_renderer::shader_list */
-	struct timespec last_used;
+	union {
+		struct {
+			GLint tex_2d_uniform;
+			GLint scale_offset_uniform;
+		} lut_3x1d;
+	} color_post_curve;
 };
 
 static const char *
@@ -336,15 +344,28 @@ gl_shader_create(struct gl_renderer *gr,
 	} else {
 		shader->color_uniform = -1;
 	}
-	shader->color_pre_curve_lut_2d_uniform =
-		glGetUniformLocation(shader->program, "color_pre_curve_lut_2d");
-	shader->color_pre_curve_lut_scale_offset_uniform =
-		glGetUniformLocation(shader->program, "color_pre_curve_lut_scale_offset");
 
-	shader->color_post_curve_lut_2d_uniform =
-		glGetUniformLocation(shader->program, "color_post_curve_lut_2d");
-	shader->color_post_curve_lut_scale_offset_uniform =
-		glGetUniformLocation(shader->program, "color_post_curve_lut_scale_offset");
+	switch(requirements->color_pre_curve) {
+	case SHADER_COLOR_CURVE_IDENTITY:
+		break;
+	case SHADER_COLOR_CURVE_LUT_3x1D:
+		shader->color_pre_curve.lut_3x1d.tex_2d_uniform =
+			glGetUniformLocation(shader->program, "color_pre_curve_lut_2d");
+		shader->color_pre_curve.lut_3x1d.scale_offset_uniform =
+			glGetUniformLocation(shader->program, "color_pre_curve_lut_scale_offset");
+		break;
+	}
+
+	switch(requirements->color_post_curve) {
+	case SHADER_COLOR_CURVE_IDENTITY:
+		break;
+	case SHADER_COLOR_CURVE_LUT_3x1D:
+		shader->color_post_curve.lut_3x1d.tex_2d_uniform =
+			glGetUniformLocation(shader->program, "color_post_curve_lut_2d");
+		shader->color_post_curve.lut_3x1d.scale_offset_uniform =
+			glGetUniformLocation(shader->program, "color_post_curve_lut_scale_offset");
+		break;
+	}
 
 	switch(requirements->color_mapping) {
 	case SHADER_COLOR_MAPPING_3DLUT:
@@ -606,18 +627,17 @@ gl_shader_load_config(struct gl_shader *shader,
 	i = GL_SHADER_INPUT_TEX_MAX;
 	switch (sconf->req.color_pre_curve) {
 	case SHADER_COLOR_CURVE_IDENTITY:
-		assert(sconf->color_pre_curve_lut_tex == 0);
 		break;
 	case SHADER_COLOR_CURVE_LUT_3x1D:
-		assert(sconf->color_pre_curve_lut_tex != 0);
-		assert(shader->color_pre_curve_lut_2d_uniform != -1);
-		assert(shader->color_pre_curve_lut_scale_offset_uniform != -1);
+		assert(sconf->color_pre_curve.lut_3x1d.tex != 0);
+		assert(shader->color_pre_curve.lut_3x1d.tex_2d_uniform != -1);
+		assert(shader->color_pre_curve.lut_3x1d.scale_offset_uniform != -1);
 		glActiveTexture(GL_TEXTURE0 + i);
-		glBindTexture(GL_TEXTURE_2D, sconf->color_pre_curve_lut_tex);
-		glUniform1i(shader->color_pre_curve_lut_2d_uniform, i);
+		glBindTexture(GL_TEXTURE_2D, sconf->color_pre_curve.lut_3x1d.tex);
+		glUniform1i(shader->color_pre_curve.lut_3x1d.tex_2d_uniform, i);
 		i++;
-		glUniform2fv(shader->color_pre_curve_lut_scale_offset_uniform,
-			     1, sconf->color_pre_curve_lut_scale_offset);
+		glUniform2fv(shader->color_pre_curve.lut_3x1d.scale_offset_uniform,
+			     1, sconf->color_pre_curve.lut_3x1d.scale_offset);
 		break;
 	}
 
@@ -645,18 +665,17 @@ gl_shader_load_config(struct gl_shader *shader,
 
 	switch (sconf->req.color_post_curve) {
 	case SHADER_COLOR_CURVE_IDENTITY:
-		assert(sconf->color_post_curve_lut_tex == 0);
 		break;
 	case SHADER_COLOR_CURVE_LUT_3x1D:
-		assert(sconf->color_post_curve_lut_tex != 0);
-		assert(shader->color_post_curve_lut_2d_uniform != -1);
-		assert(shader->color_post_curve_lut_scale_offset_uniform != -1);
+		assert(sconf->color_post_curve.lut_3x1d.tex != 0);
+		assert(shader->color_post_curve.lut_3x1d.tex_2d_uniform != -1);
+		assert(shader->color_post_curve.lut_3x1d.scale_offset_uniform != -1);
 		glActiveTexture(GL_TEXTURE0 + i);
-		glBindTexture(GL_TEXTURE_2D, sconf->color_post_curve_lut_tex);
-		glUniform1i(shader->color_post_curve_lut_2d_uniform, i);
+		glBindTexture(GL_TEXTURE_2D, sconf->color_post_curve.lut_3x1d.tex);
+		glUniform1i(shader->color_post_curve.lut_3x1d.tex_2d_uniform, i);
 		i++;
-		glUniform2fv(shader->color_post_curve_lut_scale_offset_uniform,
-			     1, sconf->color_post_curve_lut_scale_offset);
+		glUniform2fv(shader->color_post_curve.lut_3x1d.scale_offset_uniform,
+			     1, sconf->color_post_curve.lut_3x1d.scale_offset);
 		break;
 	}
 }