OpenGl immediate mode: remove imm_draw_line

Replaced all calls to `imm_draw_line` by plain `immVertex2f` calls, and
removed `imm_draw_line`, as that function was not supposed to exist in
the first place, and causes unnecessary calls to `immBegin`/`immEnd`.

Part of T49043

7 files changed, 172 insertions, 51 deletions

diff --git a/source/blender/editors/include/BIF_glutil.h b/source/blender/editors/include/BIF_glutil.h
index 30c810154b0..2dd922be372 100644
--- a/source/blender/editors/include/BIF_glutil.h
+++ b/source/blender/editors/include/BIF_glutil.h
@@ -131,7 +131,6 @@ void imm_draw_line_box_3D(unsigned pos, float x1, float y1, float x2, float y2);
 /* Draw a standard checkerboard to indicate transparent backgrounds */
 void imm_draw_checker_box(float x1, float y1, float x2, float y2);
 
-void imm_draw_line(unsigned pos, float x1, float y1, float x2, float y2);
 /**
 * Pack color into 3 bytes
 *
diff --git a/source/blender/editors/interface/interface_draw.c b/source/blender/editors/interface/interface_draw.c
index efd920aef67..c96e5c73166 100644
--- a/source/blender/editors/interface/interface_draw.c
+++ b/source/blender/editors/interface/interface_draw.c
@@ -667,8 +667,15 @@ void ui_draw_but_HISTOGRAM(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wcol)
 			immUniformColor4f(1.0f, 1.0f, 1.0f, 0.5f);
 		}
 
-		imm_draw_line(pos, rect.xmin, rect.ymin + fac * h, rect.xmax, rect.ymin + fac * h);
-		imm_draw_line(pos, rect.xmin + fac * w, rect.ymin, rect.xmin + fac * w, rect.ymax);
+		immBegin(GL_LINES, 4);
+
+		immVertex2f(pos, rect.xmin, rect.ymin + fac * h);
+		immVertex2f(pos, rect.xmax, rect.ymin + fac * h);
+
+		immVertex2f(pos, rect.xmin + fac * w, rect.ymin);
+		immVertex2f(pos, rect.xmin + fac * w, rect.ymax);
+
+		immEnd();
 	}
 
 	if (hist->mode == HISTO_MODE_LUMA) {
@@ -783,30 +790,61 @@ void ui_draw_but_WAVEFORM(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wcol),
 	immBindBuiltinProgram(GPU_SHADER_2D_UNIFORM_COLOR);
 
 	immUniformColor4f(1.0f, 1.0f, 1.0f, 0.08f);
+
 	/* draw grid lines here */
+	immBegin(GL_LINES, 12);
+
 	for (int i = 0; i < 6; i++) {
-		imm_draw_line(pos, rect.xmin + 22, yofs + (i * 0.2f) * h, rect.xmax + 1, yofs + (i * 0.2f) * h);
+		immVertex2f(pos, rect.xmin + 22, yofs + (i * 0.2f) * h);
+		immVertex2f(pos, rect.xmax + 1, yofs + (i * 0.2f) * h);
 	}
+
+	immEnd();
+
 	/* 3 vertical separation */
 	if (scopes->wavefrm_mode != SCOPES_WAVEFRM_LUMA) {
+		immBegin(GL_LINES, 4);
+
 		for (int i = 1; i < 3; i++) {
-			imm_draw_line(pos, rect.xmin + i * w3, rect.ymin, rect.xmin + i * w3, rect.ymax);
+			immVertex2f(pos, rect.xmin + i * w3, rect.ymin);
+			immVertex2f(pos, rect.xmin + i * w3, rect.ymax);
 		}
+
+		immEnd();
 	}
 	
 	/* separate min max zone on the right */
-	imm_draw_line(pos, rect.xmin + w, rect.ymin, rect.xmin + w, rect.ymax);
+	immBegin(GL_LINES, 2);
+	immVertex2f(pos, rect.xmin + w, rect.ymin);
+	immVertex2f(pos, rect.xmin + w, rect.ymax);
+	immEnd();
+
 	/* 16-235-240 level in case of ITU-R BT601/709 */
 	immUniformColor4f(1.0f, 0.4f, 0.0f, 0.2f);
 	if (ELEM(scopes->wavefrm_mode, SCOPES_WAVEFRM_YCC_601, SCOPES_WAVEFRM_YCC_709)) {
-		imm_draw_line(pos, rect.xmin + 22, yofs + h * 16.0f / 255.0f, rect.xmax + 1, yofs + h * 16.0f / 255.0f);
-		imm_draw_line(pos, rect.xmin + 22, yofs + h * 235.0f / 255.0f, rect.xmin + w3, yofs + h * 235.0f / 255.0f);
-		imm_draw_line(pos, rect.xmin + 3 * w3, yofs + h * 235.0f / 255.0f, rect.xmax + 1, yofs + h * 235.0f / 255.0f);
-		imm_draw_line(pos, rect.xmin + w3, yofs + h * 240.0f / 255.0f, rect.xmax + 1, yofs + h * 240.0f / 255.0f);
+		immBegin(GL_LINES, 8);
+
+		immVertex2f(pos, rect.xmin + 22, yofs + h * 16.0f / 255.0f);
+		immVertex2f(pos, rect.xmax + 1, yofs + h * 16.0f / 255.0f);
+
+		immVertex2f(pos, rect.xmin + 22, yofs + h * 235.0f / 255.0f);
+		immVertex2f(pos, rect.xmin + w3, yofs + h * 235.0f / 255.0f);
+
+		immVertex2f(pos, rect.xmin + 3 * w3, yofs + h * 235.0f / 255.0f);
+		immVertex2f(pos, rect.xmax + 1, yofs + h * 235.0f / 255.0f);
+
+		immVertex2f(pos, rect.xmin + w3, yofs + h * 240.0f / 255.0f);
+		immVertex2f(pos, rect.xmax + 1, yofs + h * 240.0f / 255.0f);
+
+		immEnd();
 	}
 	/* 7.5 IRE black point level for NTSC */
-	if (scopes->wavefrm_mode == SCOPES_WAVEFRM_LUMA)
-		imm_draw_line(pos, rect.xmin, yofs + h * 0.075f, rect.xmax + 1, yofs + h * 0.075f);
+	if (scopes->wavefrm_mode == SCOPES_WAVEFRM_LUMA) {
+		immBegin(GL_LINES, 2);
+		immVertex2f(pos, rect.xmin, yofs + h * 0.075f);
+		immVertex2f(pos, rect.xmax + 1, yofs + h * 0.075f);
+		immEnd();
+	}
 
 	if (scopes->ok && scopes->waveform_1 != NULL) {
 		gpuMatrixBegin3D_legacy();
@@ -831,7 +869,11 @@ void ui_draw_but_WAVEFORM(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wcol),
 			max = yofs + scopes->minmax[0][1] * h;
 			CLAMP(min, rect.ymin, rect.ymax);
 			CLAMP(max, rect.ymin, rect.ymax);
-			imm_draw_line(pos, rect.xmax - 3, min, rect.xmax - 3, max);
+
+			immBegin(GL_LINES, 2);
+			immVertex2f(pos, rect.xmax - 3, min);
+			immVertex2f(pos, rect.xmax - 3, max);
+			immEnd();
 		}
 		/* RGB (3 channel) */
 		else if (scopes->wavefrm_mode == SCOPES_WAVEFRM_RGB) {
@@ -881,7 +923,11 @@ void ui_draw_but_WAVEFORM(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wcol),
 				max = yofs + scopes->minmax[c][1] * h;
 				CLAMP(min, rect.ymin, rect.ymax);
 				CLAMP(max, rect.ymin, rect.ymax);
-				imm_draw_line(pos, rect.xmin + w + 2 + c * 2, min, rect.xmin + w + 2 + c * 2, max);
+
+				immBegin(GL_LINES, 2);
+				immVertex2f(pos, rect.xmin + w + 2 + c * 2, min);
+				immVertex2f(pos, rect.xmin + w + 2 + c * 2, max);
+				immEnd();
 			}
 		}
 		gpuMatrixEnd();
@@ -1005,8 +1051,16 @@ void ui_draw_but_VECTORSCOPE(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wco
 	immUniformColor4f(1.0f, 1.0f, 1.0f, 0.08f);
 	/* draw grid elements */
 	/* cross */
-	imm_draw_line(pos, centerx - (diam * 0.5f) - 5, centery, centerx + (diam * 0.5f) + 5, centery);
-	imm_draw_line(pos, centerx, centery - (diam * 0.5f) - 5, centerx, centery + (diam * 0.5f) + 5);
+	immBegin(GL_LINES, 4);
+
+	immVertex2f(pos, centerx - (diam * 0.5f) - 5, centery);
+	immVertex2f(pos, centerx + (diam * 0.5f) + 5, centery);
+
+	immVertex2f(pos, centerx, centery - (diam * 0.5f) - 5);
+	immVertex2f(pos, centerx, centery + (diam * 0.5f) + 5);
+
+	immEnd();
+
 	/* circles */
 	for (int j = 0; j < 5; j++) {
 		const int increment = 15;
@@ -1020,8 +1074,12 @@ void ui_draw_but_VECTORSCOPE(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wco
 	}
 	/* skin tone line */
 	immUniformColor4f(1.0f, 0.4f, 0.0f, 0.2f);
-	imm_draw_line(pos, polar_to_x(centerx, diam, 0.5f, skin_rad), polar_to_y(centery, diam, 0.5f, skin_rad),
-	                   polar_to_x(centerx, diam, 0.1f, skin_rad), polar_to_y(centery, diam, 0.1f, skin_rad));
+
+	immBegin(GL_LINES, 2);
+	immVertex2f(pos, polar_to_x(centerx, diam, 0.5f, skin_rad), polar_to_y(centery, diam, 0.5f, skin_rad));
+	immVertex2f(pos, polar_to_x(centerx, diam, 0.1f, skin_rad), polar_to_y(centery, diam, 0.1f, skin_rad));
+	immEnd();
+
 	/* saturation points */
 	for (int i = 0; i < 6; i++)
 		vectorscope_draw_target(pos, centerx, centery, diam, colors[i]);
@@ -1262,9 +1320,19 @@ void ui_draw_but_COLORBAND(uiBut *but, uiWidgetColors *UNUSED(wcol), const rcti
 	/* layer: box outline */
 	glEnable(GL_BLEND);
 	immUniformColor4f(0.0f, 0.0f, 0.0f, 0.5f);
-	imm_draw_line(position, x1, y1, x1 + sizex, y1);
+
+	immBegin(GL_LINES, 2);
+	immVertex2f(position, x1, y1);
+	immVertex2f(position, x1 + sizex, y1);
+	immEnd();
+
 	immUniformColor4f(1.0f, 1.0f, 1.0f, 0.25f);
-	imm_draw_line(position, x1, y1 - 1, x1 + sizex, y1 - 1);
+
+	immBegin(GL_LINES, 2);
+	immVertex2f(position, x1, y1 - 1);
+	immVertex2f(position, x1 + sizex, y1 - 1);
+	immEnd();
+
 	glDisable(GL_BLEND);
 	
 	/* layer: draw handles */
diff --git a/source/blender/editors/interface/interface_panel.c b/source/blender/editors/interface/interface_panel.c
index 22129cd9599..bd8fa682c49 100644
--- a/source/blender/editors/interface/interface_panel.c
+++ b/source/blender/editors/interface/interface_panel.c
@@ -453,9 +453,16 @@ static void ui_draw_anti_x(unsigned int pos, float x1, float y1, float x2, float
 	glEnable(GL_BLEND);
 
 	glLineWidth(2.0);
-	
-	imm_draw_line(pos, x1, y1, x2, y2);
-	imm_draw_line(pos, x1, y2, x2, y1);
+
+	immBegin(GL_LINES, 4);
+
+	immVertex2f(pos, x1, y1);
+	immVertex2f(pos, x2, y2);
+
+	immVertex2f(pos, x1, y2);
+	immVertex2f(pos, x2, y1);
+
+	immEnd();
 	
 	glDisable(GL_LINE_SMOOTH);
 	glDisable(GL_BLEND);
@@ -487,12 +494,29 @@ static void ui_draw_panel_scalewidget(unsigned int pos, const rcti *rect)
 	
 	glEnable(GL_BLEND);
 	immUniformColor4ub(255, 255, 255, 50);
-	imm_draw_line(pos, xmin, ymin, xmax, ymax);
-	imm_draw_line(pos, xmin + dx, ymin, xmax, ymax - dy);
+
+	immBegin(GL_LINES, 4);
+
+	immVertex2f(pos, xmin, ymin);
+	immVertex2f(pos, xmax, ymax);
+
+	immVertex2f(pos, xmin + dx, ymin);
+	immVertex2f(pos, xmax, ymax - dy);
+
+	immEnd();
 	
 	immUniformColor4ub(0, 0, 0, 50);
-	imm_draw_line(pos, xmin, ymin + 1, xmax, ymax + 1);
-	imm_draw_line(pos, xmin + dx, ymin + 1, xmax, ymax - dy + 1);
+
+	immBegin(GL_LINES, 4);
+
+	immVertex2f(pos, xmin, ymin + 1);
+	immVertex2f(pos, xmax, ymax + 1);
+
+	immVertex2f(pos, xmin + dx, ymin + 1);
+	immVertex2f(pos, xmax, ymax - dy + 1);
+
+	immEnd();
+
 	glDisable(GL_BLEND);
 }
 static void ui_draw_panel_dragwidget(unsigned int pos, const rctf *rect)
@@ -600,8 +624,15 @@ void ui_draw_aligned_panel(uiStyle *style, uiBlock *block, const rcti *rect, con
 			immUniformThemeColor(TH_PANEL_HEADER);
 			immRectf(pos, minx, headrect.ymin + 1, maxx, y);
 
-			imm_draw_line(pos, minx, y, maxx, y);
-			imm_draw_line(pos, minx, y, maxx, y);
+			immBegin(GL_LINES, 4);
+
+			immVertex2f(pos, minx, y);
+			immVertex2f(pos, maxx, y);
+
+			immVertex2f(pos, minx, y);
+			immVertex2f(pos, maxx, y);
+
+			immEnd();
 		}
 		else if (!(panel->runtime_flag & PNL_FIRST)) {
 			/* draw embossed separator */
@@ -612,9 +643,18 @@ void ui_draw_aligned_panel(uiStyle *style, uiBlock *block, const rcti *rect, con
 			}
 
 			immUniformColor4f(0.0f, 0.0f, 0.0f, 0.5f);
-			imm_draw_line(pos, minx, y, maxx, y);
+
+			immBegin(GL_LINES, 2);
+			immVertex2f(pos, minx, y);
+			immVertex2f(pos, maxx, y);
+			immEnd();
+
 			immUniformColor4f(1.0f, 1.0f, 1.0f, 0.25f);
-			imm_draw_line(pos, minx, y - 1, maxx, y - 1);
+
+			immBegin(GL_LINES, 2);
+			immVertex2f(pos, minx, y - 1);
+			immVertex2f(pos, maxx, y - 1);
+			immEnd();
 		}
 
 		glDisable(GL_BLEND);
diff --git a/source/blender/editors/interface/interface_widgets.c b/source/blender/editors/interface/interface_widgets.c
index ab6d14dd0e6..0521e7d8c7d 100644
--- a/source/blender/editors/interface/interface_widgets.c
+++ b/source/blender/editors/interface/interface_widgets.c
@@ -2702,7 +2702,12 @@ static void ui_draw_separator(const rcti *rect,  uiWidgetColors *wcol)
 	glEnable(GL_BLEND);
 	immUniformColor4ubv(col);
 	glLineWidth(1.0f);
-	imm_draw_line(pos, rect->xmin, y, rect->xmax, y);
+
+	immBegin(GL_LINES, 2);
+	immVertex2f(pos, rect->xmin, y);
+	immVertex2f(pos, rect->xmax, y);
+	immEnd();
+
 	glDisable(GL_BLEND);
 
 	immUnbindProgram();
diff --git a/source/blender/editors/screen/glutil.c b/source/blender/editors/screen/glutil.c
index 7f8454ac498..de24b8ec507 100644
--- a/source/blender/editors/screen/glutil.c
+++ b/source/blender/editors/screen/glutil.c
@@ -214,14 +214,6 @@ void imm_draw_line_box(unsigned pos, float x1, float y1, float x2, float y2)
 	immEnd();
 }
 
-void imm_draw_line(unsigned pos, float x1, float y1, float x2, float y2)
-{
-	immBegin(PRIM_LINES, 2);
-	immVertex2f(pos, x1, y1);
-	immVertex2f(pos, x2, y2);
-	immEnd();
-}
-
 void imm_draw_line_box_3D(unsigned pos, float x1, float y1, float x2, float y2)
 {
 	/* use this version when VertexFormat has a vec3 position */
diff --git a/source/blender/editors/sculpt_paint/paint_stroke.c b/source/blender/editors/sculpt_paint/paint_stroke.c
index 38827b16e31..e6113f2c2c3 100644
--- a/source/blender/editors/sculpt_paint/paint_stroke.c
+++ b/source/blender/editors/sculpt_paint/paint_stroke.c
@@ -151,9 +151,10 @@ static void paint_draw_smooth_cursor(bContext *C, int x, int y, void *customdata
 		immUniformColor4ubv(paint->paint_cursor_col);
 
 		immBegin(GL_LINES, 2);
-		imm_draw_line(pos, x, y, stroke->last_mouse_position[0],
-		              stroke->last_mouse_position[1]);
+		immVertex2f(pos, x, y);
+		immVertex2f(pos, stroke->last_mouse_position[0], stroke->last_mouse_position[1]);
 		immEnd();
+
 		immUnbindProgram();
 
 		glDisable(GL_BLEND);
@@ -176,25 +177,36 @@ static void paint_draw_line_cursor(bContext *C, int x, int y, void *customdata)
 	immBindBuiltinProgram(GPU_SHADER_2D_UNIFORM_COLOR);
 	
 	immUniformColor4ub(0, 0, 0, paint->paint_cursor_col[3]);
+
+	immBegin(GL_LINES, 2);
+
 	if (stroke->constrain_line) {
-		imm_draw_line(pos, stroke->last_mouse_position[0], stroke->last_mouse_position[1],
-		        stroke->constrained_pos[0], stroke->constrained_pos[1]);
+		immVertex2f(pos, stroke->last_mouse_position[0], stroke->last_mouse_position[1]);
+		immVertex2f(pos, stroke->constrained_pos[0], stroke->constrained_pos[1]);
 	}
 	else {
-		imm_draw_line(pos, stroke->last_mouse_position[0], stroke->last_mouse_position[1],
-		        x, y);
+		immVertex2f(pos, stroke->last_mouse_position[0], stroke->last_mouse_position[1]);
+		immVertex2f(pos, x, y);
 	}
 
+	immEnd();
+
 	glLineWidth(1.0f);
 	immUniformColor4ub(255, 255, 255, paint->paint_cursor_col[3]);
+
+	immBegin(GL_LINES, 2);
+
 	if (stroke->constrain_line) {
-		imm_draw_line(pos, stroke->last_mouse_position[0], stroke->last_mouse_position[1],
-		        stroke->constrained_pos[0], stroke->constrained_pos[1]);
+		immVertex2f(pos, stroke->last_mouse_position[0], stroke->last_mouse_position[1]);
+		immVertex2f(pos, stroke->constrained_pos[0], stroke->constrained_pos[1]);
 	}
 	else {
-		imm_draw_line(pos, stroke->last_mouse_position[0], stroke->last_mouse_position[1],
-		        x, y);
+		immVertex2f(pos, stroke->last_mouse_position[0], stroke->last_mouse_position[1]);
+		immVertex2f(pos, x, y);
 	}
+
+	immEnd();
+
 	immUnbindProgram();
 
 	setlinestyle(0);
diff --git a/source/blender/editors/space_outliner/outliner_draw.c b/source/blender/editors/space_outliner/outliner_draw.c
index 4b3b7ad6a45..f99ccd52bfc 100644
--- a/source/blender/editors/space_outliner/outliner_draw.c
+++ b/source/blender/editors/space_outliner/outliner_draw.c
@@ -1651,7 +1651,12 @@ static void outliner_draw_struct_marks(ARegion *ar, SpaceOops *soops, ListBase *
 				unsigned pos = add_attrib(format, "pos", GL_FLOAT, 2, KEEP_FLOAT);
 				immBindBuiltinProgram(GPU_SHADER_2D_UNIFORM_COLOR);
 				immThemeColorShadeAlpha(TH_BACK, -15, -200);
-				imm_draw_line(pos, 0, (float)*starty + UI_UNIT_Y, ar->v2d.cur.xmax, (float)*starty + UI_UNIT_Y);
+
+				immBegin(GL_LINES, 2);
+				immVertex2f(pos, 0, (float)*starty + UI_UNIT_Y);
+				immVertex2f(pos, ar->v2d.cur.xmax, (float)*starty + UI_UNIT_Y);
+				immEnd();
+
 				immUnbindProgram();
 			}
 		}